Academic literature on the topic 'Reduced irrigation'
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Journal articles on the topic "Reduced irrigation"
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Kasniya, Pawan Kumar, and Opinder Singh Sandhu. "Alternate wetting and drying irrigation: A strategic approach to increase water productivity and managing of sheath blight disease in rice." JOURNAL OF MYCOLOGY AND PLANT PATHOLOGY 54, no. 02 (2024): 122. http://dx.doi.org/10.59467/jmpp.2024.54.122.
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The traditional practice of continuous flooding irrigation in rice cultivation has resulted in excessive groundwater exploitation and low water productivity of crop. This study aimed to evaluate the impact of two irrigation techniques, alternate wetting and drying (AWD) and continuous flooding (CF) on the development of sheath blight disease (Rhizoctonia solani Kuhn) and water productivity of poplar rice cultivar PR 121 during the kharif seasons 2021 and 2022. Irrigating the rice fields two days after percolation of ponded water as follow AWD technique was identified the optimal irrigation practice for saving irrigation water and managing of sheath blight disease in rice crop. The AWD technique of irrigation was significantly reduced the disease severity (32.3%), number of irrigations (21.3%) and volume of irrigation water (20.3%), while increasing water productivity (29.9%) and grain yield (1.26%) as compared to the traditional continuous flooding system in rice cultivation.. KEYWORDS :Irrigation, severity, sheath blight, water productivity, yield
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Barber, J. S., and R. S. Jessop. "Factors affecting yield and quality in irrigated wheat." Journal of Agricultural Science 109, no. 1 (1987): 19–26. http://dx.doi.org/10.1017/s002185960008093x.
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SummaryTwo field experiments examined the effects of nitrogen fertilizer, irrigation frequency and three wheat varieties on the yield and quality of irrigated wheat on a heavy clay soil. In the first experiment, with irrigation supplied to all plots at mid-tillering and close to ear emergence, there were negative effects of nitrogen fertilizer on grain yield with the reverse occurring with grain protein. The variety Songlen had one of the highest grain yields combined with higher milling yields and flour protein. In the second experiment, yield was maximized with at least two irrigations, whilst increasing irrigation frequency reduced flour protein and dough development time. While WW15 gave the highest yields irrespective of nitrogen or irrigation treatments, this variety had the lowest flour protein. With only one irrigation or without irrigation, nitrogen fertilizer increased grain protein; more frequent irrigation reduced mean flour protein.
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Taylor, Donald C. "Reduced Pressure Irrigation Investment Economics." Water Resources Research 22, no. 2 (1986): 121–28. http://dx.doi.org/10.1029/wr022i002p00121.
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Chen, Ji-Jhong, Youping Sun, Lorence R. Oki, et al. "Climate-ready Landscape Plants: Garden Roses Trialed at Reduced Irrigation Frequency in Utah, USA." HortTechnology 33, no. 5 (2023): 477–92. http://dx.doi.org/10.21273/horttech05252-23.
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Increased urban and suburban populations in the arid western United States have resulted in more water demand; however, water availability in the region has become limited because of inadequate precipitation. Recent droughts have led to restrictions on irrigating landscape plants. Garden rose (Rosa ×hybrida) is commonly used as flowering plants in residential landscapes, but its drought tolerance has not been widely studied. The objective of this study was to determine the impact of reduced irrigation frequency on visual quality, plant growth, and physiology of five garden rose cultivars, including ChewPatout (Oso Easy® Urban Legend®), Meibenbino (Petite Knock Out®), MEIRIFTDAY (Oso Easy® Double Pink), Overedclimb (Cherry Frost™), and Radbeauty (Sitting Pretty™). Twenty-four plants of each rose cultivar were established in a trial plot at Utah Agricultural Experiment Station Greenville Research Farm (North Logan, UT, USA) in Summer 2021. Plants were randomly assigned to one of three deficit irrigation treatments for which irrigation frequencies were calculated using 80% reference evapotranspiration (ETO) (high), 50% ETO (medium), and 20% ETO (low). The total volumes of irrigation water applied to each plant were 345.6, 172.8, and 43.2 L for the high, medium, and low irrigation frequencies, respectively, during the deficit irrigation trial from 12 May to 30 Sep 2022. Root zones were wetted more frequently as irrigation frequency increased from low to high irrigation frequencies. Decreased irrigation frequency increased the number of visibly wilted and damaged leaves on all rose cultivars. However, only ‘Meibenbino’ and ‘MEIRIFTDAY’ exhibited a reduction in overall appearance under decreased irrigation frequency. The relative growth indices of both ‘Meibenbino’ and ‘MEIRIFTDAY’ decreased by 6%, whereas the dry weights of their leaves decreased by 37% and 36%, respectively, as irrigation decreased from high to low frequencies. Roses in this study appeared to decrease stomatal conductance up to 51% when irrigation decreased from high to low frequencies, or when air temperature increased. ‘Meibenbino’ and ‘MEIRIFTDAY’ exhibited unacceptable overall appearance, growth reduction, and higher leaf–air temperature differences, and they were less tolerant to reduced irrigation. Although the ‘Radbeauty’ maintained plant growth under the reduced irrigation frequency, the large leaf size led to a more visibly wilted appearance and the potential for heat stress, thus impairing visual quality. ‘ChewPatout’ and ‘Overedclimb’ were most tolerant to deficit irrigation at 20% ETO and maintained plant growth with acceptable visual quality and lower leaf temperatures when they received one irrigation during the growing season.
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Zaman, R., A. R. Akanda, S. K. Biswas, and M. R. Islam. "Effect of Deficit Irrigation on Raised Bed Wheat Cultivation." Cercetari Agronomice in Moldova 50, no. 4 (2017): 17–28. http://dx.doi.org/10.1515/cerce-2017-0032.
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Abstract The experiment was conducted during Rabi season of 2015-2016 and 2016-2017 at the Regional Agricultural Research station, BARI, Ishurdi, Pabna, Bangladesh, to determine the water requirements of wheat on raised bed and the effect of different deficit irrigation on yield, water use efficiency and applied water productivity under raised bed wheat. This study consisted of following irrigation treatments: T1 = Irrigations up to 100% field capacity (FC) at crown root initiation (CRI), botting and grain filling stages (flat bed), T2 = Irrigations up to 100% FC at CRI, botting and grain filling stages on raised bed, T3 = Irrigations up to 80% FC at CRI, botting and grain filling stages on raised bed and T4 = Irrigations up to 60% FC at CRI, botting and grain filling stages on raised bed and laid out in a randomize complete block design with three replications. The result showed that significant effect of irrigation treatments were observed on plant height, spike per m2 and grain yield. Highest grain yield (4.66 t/ha) was obtained from treatment, irrigations up to 100% FC at CRI, botting and grain filling stages on raised bed, followed by irrigation up to 100% FC at same stages on flat bed. At raised bed wheat cultivation saving 14.30% water with increasing 15.66% grain yield than flat bed. Besides, comparing deficit irrigation (20% and 40% of full irrigation) and full irrigation condition on raised bed seeding system water use could be reduced about 4.18% to 5.57%, while scarifying 18.20% to 32.33% grain yield, where reduced 14.17% to 27.54% water use efficiency. Maximum applied water productivity 1.81 kg m−3 was observed in raised bed full irrigation condition. The rate of daily evaporation started to increase as the temperature started to rise and humidity started to decrease during the crop growing period. The results will be helpful for taking policy decision regarding efficient irrigation and water management under prevailing water scarce situation.
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Sapkota, Anish, Amir Haghverdi, Claudia C. E. Avila, and Samantha C. Ying. "Irrigation and Greenhouse Gas Emissions: A Review of Field-Based Studies." Soil Systems 4, no. 2 (2020): 20. http://dx.doi.org/10.3390/soilsystems4020020.
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Irrigation practices can greatly influence greenhouse gas (GHG) emissions because of their control on soil microbial activity and substrate supply. However, the effects of different irrigation management practices, such as flood irrigations versus reduced volume methods, including drip and sprinkler irrigation, on GHG emissions are still poorly understood. Therefore, this review was performed to investigate the effects of different irrigation management strategies on the emission of nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4) by synthesizing existing research that either directly or indirectly examined the effects of at least two irrigation rates on GHG emissions within a single field-based study. Out of thirty-two articles selected for review, reduced irrigation was found to be effective in lowering the rate of CH4 emissions, while flood irrigation had the highest CH4 emission. The rate of CO2 emission increased mostly under low irrigation, and the effect of irrigation strategies on N2O emissions were inconsistent, though a majority of studies reported low N2O emissions in continuously flooded field treatments. The global warming potential (GWP) demonstrated that reduced or water-saving irrigation strategies have the potential to decrease the effect of GHG emissions. In general, GWP was higher for the field that was continuously flooded. The major finding from this review is that optimizing irrigation may help to reduce CH4 emissions and net GWP. However, more field research assessing the effect of varying rates of irrigation on the emission of GHGs from the agricultural field is warranted.
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Honorata, Danilčenko, Jarienė Elvyra, Televičiutė Dalė, et al. "Reduced microbiological contamination following irrigation of germinated seed for foods." Czech Journal of Food Sciences 36, No. 2 (2018): 139–45. http://dx.doi.org/10.17221/267/2017-cjfs.
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Germinated seeds are rich in various nutrients but are vulnerable to fungal contamination which favours micromycete formation on the sprouts. The main aim of this work was an investigation of strategies to reduce the contamination of sprouted seed foods. Over the course of 96 hours of sprouting, seeds of organic spring wheat (Triticum aestivum L.), winter wheat (Triticum aestivum L.), naked oat (Avena nuda L.), triticale (xTriticosecale) and rye (Secale cereale L.) were irrigated in water filtered using the Pazdroid Med-1500 filtration device with and without 4% ethyl alcohol. Germinated seeds were stored at 18°C for one, three and seven days and the levels of Mucor spp., Penicillium spp., Alternaria spp., Aspergillus spp., Fusarium spp. and Bipolaris spp were determined. Micromycete numbers were greater in sprouted winter wheat and rye but were reduced when these were soaked and irrigated with filtered water and filtered water containing 4% ethyl alcohol. Filtered water led to greater reductions in micromycete numbers in sprouted winter and spring wheat than in other seeds.
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Xu, C., and D. I. Leskovar. "Growth, physiology and yield responses of cabbage to deficit irrigation." Horticultural Science 41, No. 3 (2014): 138–46. http://dx.doi.org/10.17221/208/2013-hortsci.
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Field experiments were conducted in two seasons to investigate growth, physiology and yield responses of cabbage (Brassica oleracea L. cvs Pennant and Rio Grande) to deficit irrigation. In 2012 season, 50% of crop evapotranspiration (ETc) irrigation temporarily decreased plant size, reduced leaf area, fresh weight, relative water content, specific leaf area and gas exchange during late development, and decreased head fresh weight, size, marketable and total yield. Deficit irrigation at 75% ETc had little influence on plant growth and physiology, but it still reduced both marketable and total yield. In 2013 season, 75% ETc irrigation had little influence on plant growth, leaf characteristics, photosynthetic rate, head fresh weight and size, but it temporarily increased chlorophyll and carotenoid content, and decreased stomata conductance, transpiration, and marketable yield. Pennant, the green-head cultivar, had higher photosynthetic rate, head fresh weight, marketable and total yield than the red-head cultivar Rio Grande. In both seasons, deficit irrigations did not influence cabbage head dry weight, indicating that most yield reduction under deficit irrigations is related to water content.  
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Kirnak, H., C. Kaya, D. Higgs, I. Bolat, M. Simsek, and A. Ikinci. "Effects of preharvest drip-irrigation scheduling on strawberry yield, quality and growth." Australian Journal of Experimental Agriculture 43, no. 1 (2003): 105. http://dx.doi.org/10.1071/ea02045.
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Strawberry (Fragaria × ananassa Duch) cultivars, Oso Grande and Camarosa were grown in the field from July 1999 to May 2000 in order to investigate the effectiveness of preharvest drip-irrigation management on fruit yield, quality (i.e. soluble dry matter, fruit size), leaf macro-nutrient composition and normal growth parameters. All plots were irrigated uniformly until 2 weeks before harvest. Differential treatments were then imposed ranging from a complete cut-off of irrigation to full irrigation through the harvest period. Preharvest drip-irrigation management treatments were (i) complete irrigation cut-off, dry (D), (ii) normal irrigation based on class A pan and percentage cover (C), (iii) 75% of normal irrigation, C (IR1), (iv) 50% of normal irrigation, C (IR2), and (v) 25% of normal irrigation, C (IR3). Normal irrigation (control, C) was created by irrigating plants once every 2 days at 100% A pan (Epan) evaporation. No irrigation (D) and IR3 treatments caused reductions in most parameters measured, except water-soluble dry matter concentrations (SDM) in fruit compared with other treatments. There were no significant differences between C, IR1, and IR2 treatments in normal growth parameters or leaf nutrient composition. Fruit size and SDM were both significantly affected by late-season irrigation management; individual fruit weight was significantly reduced and SDM increased even in the IR2 and IR3 treatments compared with control values. Fruit yield was not affected significantly by reduced water application except in the D treatment. These results clearly indicate that reduced preharvest irrigation was partially detrimental; a small reduction in irrigation (IR1) had little or no effect but 50% or less of normal irrigation, while not reducing overall fruit yield, resulted in smaller fruits.
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Giotakis, A. I., E. M. Karow, M. O. Scheithauer, R. Weber, and H. Riechelmann. "Saline irrigations following sinus surgery - a controlled, single blinded, randomized trial." Rhinology journal 54, no. 4 (2016): 302–10. http://dx.doi.org/10.4193/rhino16.026.
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Background: Chronic rhinosinusitis (CRS) is a common health problem. If medical treatment fails, endonasal sinus surgery is a valuable treatment option. A thorough postsurgical treatment is needed including, among others, nasal saline irrigations (NSI). In this prospective, controlled, single blinded, randomized trial, we aimed to evaluate efficacy of nasal saline irrigations following endonasal sinus surgery in CRS-patients with nasal polyps. Methodology: We examined patient's nasal symptoms, general quality of life and postoperative condition of the mucosa. We also investigated whether or not NSI reduced the number of missed workdays after surgery (MWD). Patients were randomized into an irrigation and non-irrigation arm. Results: Following treatment, mean nasal sum-score in the irrigation arm was 4.4 and in the non-irrigation arm it was 6.3. Accordingly, mean general sum-score in the irrigation arm was 2.5 and in the non-irrigation arm 4.8. Thus, nasal irrigation led to a more pronounced improvement of nasal and general symptoms than in the non-irrigation arm. No differences were observed in postoperative condition of mucosa or number of MWD. Conclusions: Nasal irrigation improves symptoms score after ESS in patients with CRSwNP.
Dissertations / Theses on the topic "Reduced irrigation"
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Kittock, David L., Roger A. Selley, and B. Brooks Taylor. "Comparison of Reduced Irrigation Strategies in Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/204073.
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Martin, E. C., K. O. Adu-Tutu, W. B. McCloskey, S. H. Husman, P. Clay, and M. Ottman. "Reduced Tillage Effects on Irrigation Management in Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 2003. http://hdl.handle.net/10150/197914.
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Conservation or reduced tillage practices in cotton-based crop rotation systems were studied in field experiments initiated at Marana, Coolidge and Goodyear in 2001. Following barley cover and grain crops, soil and water management assessments were made during the 2002 cotton season at the three sites. Cover and grain crop residues and a lack of tillage prior to planting cotton or during the cotton season increased the infiltration of irrigation water into coarsetextured soils, slowed irrigation advance times, and increased the amount of irrigation water used at two of the three sites compared to conventional tillage treatments.
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Gonz?alez, Rico Antonio. "Growth characteristics and water demand of three Quercus species under reduced irrigation using a computer-controlled irrigation system /." The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487843314696831.
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Ottman, M. J., T. A. Doerge, M. D. Sheedy, and R. T. Ramage. "Nitrogen Fertilizer Rates for Barley Bred for Reduced Water Use." College of Agriculture, University of Arizona (Tucson, AZ), 1991. http://hdl.handle.net/10150/201355.
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Barley lines have been developed for one-irrigation conditions. The purpose of these studies is to provide information required to develop recommendations for nitrogen fertilizer practices for one - irrigation barley. A total of nine field studies were conducted at the Marana and Maricopa Agricultural Centers testing six nitrogen rates ranging from 0 to 200 lbs N/A under a variety of conditions. The optimum nitrogen fertilizer rate ranged from 0 to 40 lbs N /A. No relationship was established between optimum nitrogen fertilizer rate and preplant soil nitrate, previous crop, planting date, or number of irrigations (1 vs. 2). Based on the results of this and other studies, a nitrogen rate of 40 to 50 lbs N/A is usually adequate for one-irrigation barley, and nitrogen rates greater than 80 to 100 lbs N/A is considered excessive.
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De, Villiers Adriaan Jacobus. "Seasonal growth patterns and water relations in response to reduced irrigation regimes in mango (Mangifera indica L.)." Diss., University of Pretoria, 2001. http://hdl.handle.net/2263/29890.
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Karam, Nabila Subhi. "Overhead sprinkler irrigation strategies to reduce water and nitrogen loss from container-grown plants." Diss., Virginia Tech, 1993. http://hdl.handle.net/10919/40069.
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The overall objective of this study was to determine the influence of intermittent water application via overhead irrigation on water and N leaching, substrate water distribution, and plant growth in a pine bark substrate. Intermittent irrigation was defined as the application of a plants' daily water allotment in multiple applications with prescribed intervals between applications. Specifically, experiments were conducted to determine: 1) the influence of water application rate and pre-irrigation substrate moisture content on water application efficiency, 2) the influence of the number of intermittent applications and interval duration between applications on application efficiency, 3) substrate water distribution after intermittent irrigation, 4) efficiency of intermittent irrigation in unamended and sand-amended pine bark, and 5) influence of intermittent irrigation on plant growth. In all experiments, Marigold (<u>Tagetes erecta</u> L. 'Apollo') was grown in unamended or sand-amended pine bark in 3.8-liter containers. After saturation, bark was allowed to dry via evapotranspiration to targeted moisture deficits after which irrigation treatments were applied via a simulated overhead irrigation system. In experiments evaluating intermittent irrigation, water was applied intermittently (multiple applications with intervals between applications) or continuously (single application). After 1 h drainage, collected leachate was measured and analyzed (in two experiments) for electrical conductivity, N0₃-N and NH₄-N and water application efficiency (percentage of applied water that is retained in the substrate) determined. There was an inverse linear relationship between water application rate and efficiency. Leachate N (total) increased linearly as application rate increased. Efficiency increased curvilinearly and leachate N (total and concentration) increased linearly as pre-irrigation substrate moisture content decreased. Efficiency of intermittent irrigation was greater than continuous irrigation over a range of pre-irrigation substrate moisture contents, and in both unamended and sand-amended pine bark. Intermittent efficiency increased linearly as interval duration between applications increased. Efficiency of five 60 ml applications was greater than three 100 ml applications. Gravimetric moisture content of the bottom third of the substrate was greater with intermittent than continuous irrigation. Intermittent efficiency was greater in pine bark than in sand-amended pine bark when the water deficit from container capacity was the same for both substrates. Repeated intermittent irrigations resulted in less water and N leaching compared to continuous irrigation. Intermittent irrigation did not result in substrate nutrient accumulation and had no adverse effect on plant growth. Fresh and dry root weights and shoot and root N concentrations were greater with intermittent irrigation than continuous irrigation.<br>Ph. D.
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Kotze, Madelize J. "Investigating the efficacy of medium pressure UV and hydrogen peroxide as on-farm treatment methods to reduce the microbial load of irrigation water." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96867.
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Thesis (MSc Food Sc)--Stellenbosch University, 2015.<br>ENGLISH ABSTRACT: Many South African farmers are forced to use water from nearby rivers for crop irrigation, since it is
the most affordable and sometimes only source of water available to them. During this research
project, a baseline study was performed on a farm irrigating fresh produce with water obtained
from the Eerste River. The baseline study was done over a five month period, at six preselected
sampling points, to determine the microbial and physico-chemical parameters of the water so a
baseline could be established to compare the results to when the ultraviolet (UV) apparatus was
installed (February 2013). Aerobic colony count (ACC), total coliforms (TC) and Escherichia coli
(E. coli) were tested for during the microbiological study, while the physico-chemical analysis
comprised of temperature, pH, conductivity, chemical oxygen demand (COD), alkalinity and total
soluble solids (TSS). The UV treatment study was also performed over a five month timeline, at
eight different sampling points (original six sampling points, with additional sampling points before
and after UV). The same microbiological tests were performed during the UV treatment study, but
turbidity and percentage ultraviolet transmittance (% UVT) were performed additionally during
physico-chemical analysis.
During the baseline study ACC, TC and E. coli counts as high as 9 600 cfu.mL-1, 13 799
MPN.100 mL-1 and 2 098 MPN.100 mL-1 were isolated at the river (Sampling Point 1), respectively.
While performing the UV treatment study ACC, TC and E. coli counts as high as 142 000 cfu.mL-1,
241 960 MPN.100 mL-1 and 6 867 MPN.100 mL-1 were isolated at the river, respectively. As a
result it was concluded that the Eerste River was mostly unsuitable for irrigation of fresh produce
that are consumed raw. The higher counts in the river, during the UV treatment study might be
attributed to the increase in rainfall that occurred in the sampling months (March to July 2013).
The counts as measured at the point of irrigation are considered of greater importance,
since the counts present in the river might still decrease to below the guideline levels after passing
through sand filters and the addition of hydrogen peroxide (current mode of treatment) or after
passing through the UV in the UV treatment study. The ACC, TC and E. coli counts during the
baseline study were as high as 8 800 cfu.mL-1, 24 196 MPN.100 mL-1 and 85 MPN.100 mL-1 at the
point of irrigation (Sampling Point 6), respectively. After hydrogen peroxide addition average logreductions
ranging between 0.65 and 1.13 were seen, but reduction was never constant. The counts at the point of irrigation remained more or less constant compared to the river
due to contamination that occurred at the sand filters, making the water unsuitable for irrigation of
fresh produce in terms of ACC and TC counts. In the UV treatment study ACC, TC and E. coli
counts were as high as 35 000 cfu.mL-1, 10 462 MPN.100 mL-1 and 63 MPN.100 mL-1 at the point
of irrigation (Sampling Point 8), respectively. Average log-reductions in the range of 0.90 to 1.25
were achieved, but it was inconsistent. After treatment with chlorine and re-sanding of the sand
filters, no further contamination occurred and counts decreased to below guideline limits, making
the water safe for irrigational use in terms of all of the microbiological parameters. Not only is UV treatment more effective in reducing microbiological counts than H2O2, it is also relatively less
expensive in the long term. Hydrogen peroxide treatment of water amounts to a very high capital
expense every month, whereas UV may seem expensive when starting up, but the monthly
operating cost thereafter is marginally less than for H2O2.
It is of great importance to farmers to find a treatment that would reduce the counts in the
river water to below the guideline limits required for safe irrigation since pathogens can be carried
over from water onto fresh produce, resulting in an increase in produce-associated foodborne
outbreaks and loss of consumer trust.<br>AFRIKAANSE OPSOMMING: Menigte Suid-Afrikaners is afhanklik van nabygeleë riviere om hulle oeste te besproei aangesien
dit meestal die mees bekostigbare en soms enigste bron tot hul beskikking is. Tydens hierdie
projek is ‘n grondslag sowel as ‘n UV behandelingsmetode studie uitgevoer op ‘n plaas wat vars
vrugte en groente besproei met water water wat hul vanuit die Eersterivier verkry. Die
grondslagstudie is oor ‘n tydperk van vyf maande uitgevoer by ses voorafgekose punte. Dit is
gedoen om die mikrobiologiese sowel as chemiese parameters van die water te bepaal sodat ‘n
grondslag beskikbaar kon wees om met resultate te vergelyk wat met behulp van die
ultravioletmasjien verkry is (in Februarie 2013 geïnstalleer). Tydens die mikrobiologiese studie is
daar vir aerobiese koliform tellings (ACC), totale koliforme (TC) en Escherichia coli (E. coli)
getoets. Tydens die chemiese analise is temperatuur, pH, konduktiwiteit, chemiese suurstof
benodiging, alkaliniteit en totale oplosbaie vastestowwe in die water getoets. Die UV
behandelingsmetode studie is ook oor ‘n tydperk van vyf maande uitgevoer, met twee addisionale
toetspunte by. Presies dieselfde mikrobiologiese analises as wat tydens die grondslag studie
uitgevoer is, is tydens die UV behandelingsmetode studie uitgevoer, maar vir die chemiese analise
het turbiditeit en persentasie ultraviolet transmissie van die water bygekom.
Gedurende die grondslag studie was ACC, TC and E. coli tellings so hoog as 9 600
cfu.mL-1, 13 799 MPN.100 mL-1 en 2 098 MPN.100 mL-1 onderskeidelik uit die rivier geïsoleer
(Punt 1). Tydens die UV behandelingsmetode studie was ACC, TC en E. coli tellings so hoog as
142 000 cfu.mL-1, 241 960 MPN.100 mL-1 en 6 867 MPN.100 mL-1 onderskeidelik by die rivier
geïsoleer. Gevolglik is daar afgelei dat die Eersterivier se water meestal ongeskik is om te gebruik
vir die besproeiing van vars groente en vrugte wat rou geëet word sonder dat enige verdere
behandeling plaasvind. Die hoër tellings wat tydens die UV behandelingsmetode in die rivier
sigbaar was kan hoofsaaklik toegeskryf word aan die toename in reënval in daardie tyd (Maart tot
Julie 2013).
Tellings soos gemeet by die punt van besproeiing is wel van groter belang as die wat
aangeteken is by die rivier; aangesien die tellings wat in die rivier aangeteken is steeds kan
afneem tot onder aanvaarbare hoeveelhede soos in die standaarde uiteengesit, want die water
moet steeds deur sandfilters beweeg en word ook huidiglik deur waterstofperoksied behandel
tydens die die grondslagstudie of beweeg deur die UV apparaat in die UV behandelingsmetode
studie. Die ACC, TC en E. coli tellings soos gemeet by die besproeiingspunt (Punt 6) was so hoog
as 8 800 cfu.mL-1, 24 196 MPN.100 mL-1 en 85 MPN.100 mL-1, onderskeidelik. Na
waterstofperoksied byvoeging was die gemiddelde log-reduksies sigbaar, tussen 065 en 1.13,
maar afnames was nooit konstant nie. Die tellings by die punt van besproeiing het ongeveer
konstant gebly in vergelyking met die tellings wat by die rivier aangeteken is; moontlik as gevolg
van die hoë kontaminasie vlakke in die sandfilters. Kontaminasie van sandfilters het veroorsaak
dat die water ongeskik was vir die gebruik van besproeiing van vars groente as gevolg van die hoë ACC en TC vlakke. Tydens die UV behandelingsmetode studie is ACC, TC en E. coli tellings so
hoog as 35 000 cfu.mL-1, 10 462 MPN.100 mL-1 en 63 MPN.100 mL-1, onderskeidelik aangeteken
(Punt 8). Gemiddelde log-reduksies tussen 0.90 tot 1.25 was verkry, maar behandeling en
afnames in tellings was nie konstant nie. Nadat die sandfilters met chloor behandel is en die sand
daarin vervang is, het geen verdere kontaminasie by die punt voorgekom nie. Nadat al die
voorafgenoemde behandelings afgehandel is, het die tellings tot laer as die van die standaarde
gedaal en dus was die water nou veilig om te gebruik vir besproeiingsdoeleindes in terme van die
mikrobiologiese parameters. Die UV behandelingsmetode is nie net meer effektief in die verlaging
van mikrobiologiesese tellings as waterstofperoksied nie, dis ook heelwat goedkoper in die
langtermyn. Waterstofperoksied behandeling van water lei tot ‘n baie hoë kapitale onkoste per
maand, terwyl UV baie duur mag voorkom in die beginfase, maar die maandelikse kostes is
aansienlik laer as die van waterstofperoksied en maak sodoende op daarvoor.
Dit is van uiterste belang vir boere om ‘n water behandelingsmetode te vind wat die hoë
tellings in die rivier sal afbring tot laer as Suid-Afrikaanse en Kanadese riglyne; aangesien
patogene oorgedra kan word van vars vrugte en groente. Laasgenoemde kan tot ‘n drastiese
toename in vars voedsel geassosieerde siektes en gevolglik ‘n afname in die vertroue wat ‘n kliënt
in ‘n produk plaas, lei.
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Falk, James. "Using a reamer-irrigator-aspirator reduces femoral intramedullary pressure during simulated total knee arthroplasty." Connect to resource, 2008. http://hdl.handle.net/1811/32035.
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Golden, Lisa C. "Evaluation of Management Strategies and Physiological Mechanisms of Agrostis Species for Reduced Irrigation Environments." 2014. https://scholarworks.umass.edu/masters_theses_2/19.
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Water is a basic necessity for turfgrass growth and metabolic processes, with optimal levels required for the maintenance of turf quality and function. As water restrictions for irrigation of landscapes become more widespread across the United States, turfgrass managers will need to rely on management strategies to improve the performance of turfgrasses under reduced irrigation environments. Therefore, the objectives of the research were to (i) compare the performance of different Agrostis species and cultivars under reduced irrigation, (ii) evaluate the use of wetting agents for maintaining turf quality under reduced irrigation, (iii) and examine the physiological mechanisms associated with improved drought resistance traits of Agrostis species. To address our primary objectives, we conducted a two-year field study comparing cultivars of three bentgrass species, including ‘Revere’ and ‘Tiger II’ colonial bentgrasses (Agrostis capillaris), ‘Legendary’ and ‘Greenwich’ velvet bentgrasses (A. canina), and ‘13M’, ‘T-1’, ‘L-93’, and ‘Penncross’ creeping bentgrasses (A. stolonifera) in response to reduced irrigation with and without the use of a wetting agent. In general, the use of a wetting agent did not result in any significant differences in turf quality or soil moisture content among treatments. There were significant differences in turf quality among bentgrass species and cultivars under reduced irrigation. Colonial bentgrass cultivars maintained high turf quality, and were found to be well suited for fairways under reduced irrigation. Due to excessive thatch accumulation in our study, velvet bentgrass cultivars exhibited significant declines in quality regardless of irrigation level. Among creeping bentgrass cultivars, T-1 exhibited improved drought tolerance compared to the older cultivars of creeping bentgrass. Based on results from the field study, we further evaluated the drought resistance and recovery characteristics among five cultivars of colonial bentgrass (‘Barking’, 'Tiger II’, ‘Revere’, ‘Capri’, and ‘Greentime’). Under moderate drought stress, Barking, Tiger II, and Revere all exhibited lower leaf relative water content levels compared to Capri and Greentime, although no significant differences in turf quality or soil water content were observed during the drought period. Following re-watering, Barking and Tiger II exhibited the most rapid recovery from drought (as measured by percent green cover), while Capri and Greentime exhibited delayed recovery. Therefore, although significant differences in turf performance during drought stress were not observed, recovery potential seems to vary among the different cultivars of colonial bentgrass.
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Hall, James Olin. "Limiting root zone leaching to reduce groundwater contamination in sandy soils." 1991. http://www.cdpr.ca.gov/docs/empm/pubs/ehapreps/eh9110.pdf.
Full textBooks on the topic "Reduced irrigation"
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Girgin, Burhan N. Surge flow furrow irrigation and crop residues to reduce soil erosion. 1992.
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Weiss, Harvey. 4.2 ka BP Megadrought and the Akkadian Collapse. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780199329199.003.0004.
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The Akkadians, of southern Mesopotamia, created the first empire ca. 2300 BC with the conquest and imperialization of southern irrigation agriculture and northern Mesopotamian dry-farming landscapes. The Akkadian Empire conquered and controlled a territory of roughly 30,000 square kilometers and, importantly, its wealth in labor and cereal crop-yields. The Empire maintained a standing army, weaponry, and a hierarchy of administrators, scribes, surveyors, craft specialists, and transport personnel, sustainable and profitable for about one hundred years. Archaeological excavations indicate the empire was still in the process of expansion when the 2200 BC–1900 BC/4.2–3.9 ka BP global abrupt climate change deflected or weakened the Mediterranean westerlies and the Indian Monsoon and generated synchronous megadrought across the Mediterranean, west Asia, the Indus, and northeast Africa. Dry-farming agriculture domains and their productivity across west Asia were reduced severely, forcing adaptive societal collapses, regional abandonments, habitat-tracking, nomadization, and the collapse of the Akkadian Empire. These adaptive processes extended across the hydrographically varied landscapes of west Asia and thereby provided demographic and societal resilience in the face of the megadrought’s abruptness, magnitude, and duration.
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Jones, Isabel, Andrea Lund, Gilles Riveau, et al. Ecological control of schistosomiasis in Sub-Saharan Africa: restoration of predator-prey dynamics to reduce transmission. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198789833.003.0015.
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Human modification of the landscape can increase the transmission of schistosomiasis, a snail-borne parasitic infection prevalent in Sub-Saharan Africa. The construction of dams and irrigation schemes increases the habitat available for the freshwater snails that serve as the parasite’s intermediate host. Schistosomiasis is considered both a cause and consequence of poverty. The disease is treatable, but its persistence in the environment makes it difficult to prevent reinfection after treatment. Interventions that address the environmental source of infection are a necessary complement to mass treatment campaigns. We present a promising ecological solution for schistosomiasis control that harnesses predator-prey dynamics to suppress snail populations and parasite transmission. We present data on the ecological and epidemiological impacts of restoring Macrobrachium vollenhovenii, a freshwater prawn native to the Senegal River. Harnessing ecology to control disease transmission may be a viable strategy in other geographic regions and other disease systems.
Book chapters on the topic "Reduced irrigation"
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Cuhadar, Muhammed. "The Impact of Drought on Agricultural Production and Agricultural Adaptation to Drought." In Agricultural Economics and Climate Change. Nobel Tip Kitabevleri, 2024. http://dx.doi.org/10.69860/nobel.9786053359432.5.
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Drought is a significant natural disaster that seriously impacts agriculture and is becoming an increasingly prevalent issue worldwide. The effects of this disaster on agriculture present severe challenges both in terms of productivity and agricultural sustainability. Consequently, adaptation measures to combat drought are of great importance. Drought can cause significant yield losses in agricultural production. The reduction or depletion of water resources leads to water stress in plants, adversely affecting their growth and productivity. Particularly during drought periods, limited irrigation opportunities exacerbate drought stress on agricultural lands. This situation results in quality loss in agricultural products, decreased productivity, and reduced harvest quantities. Drought also negatively impacts soil health. Decreased moisture levels can lead to soil structure degradation and increased erosion risk. Erosion reduces the productivity of agricultural lands, causing long-term sustainability issues in agricultural production. Adaptation measures to combat drought can help increase the resilience of the agricultural sector and make it more resistant to drought stress. These measures include water management, improved irrigation techniques, the use of drought-tolerant crop varieties, soil management practices, and agricultural policies that support climate change adaptation. Especially during drought periods, the efficient use and conservation of water resources are critical to ensuring the continuity of agriculture. Technological advancements that enhance water efficiency and irrigation systems that better manage the water cycle can help agriculture cope more effectively with drought. In conclusion, the ability of the agricultural sector to adapt to drought is of great importance. Efforts in areas such as the conservation of water resources, soil management, crop diversity, and technological innovations can contribute to making agriculture more resilient to natural disasters like drought. This, in turn, can strengthen food security and agricultural sustainability on more solid foundations. This study discusses the negative effects of drought on agriculture and adaptation strategies that can minimize these effects. It focuses on necessary precautions, implementation methods, steps to be taken, and policies to be developed. Additionally, it emphasizes the need for adaptation strategies to combat drought.
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Njagi, Timothy, and Yukichi Mano. "Toward a Green Revolution in Sub-Saharan Africa: Farm Mechanization in the Mwea Irrigation Scheme." In Emerging-Economy State and International Policy Studies. Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-5542-6_5.
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AbstractGovernments in Sub-Saharan Africa (SSA) have made concerted efforts to improve farmers’ adoption of modern technologies in their farm operations to realize a rice Green Revolution, improve food security, and alleviate poverty. However, smallholder farmers’ access to farm mechanization in SSA remains constrained due to supply-side and demand-side challenges. On the supply side, the market for agricultural machinery services is often underdeveloped. On the demand side, the smallholders with inadequate knowledge of improved rice cultivation practices have limited demand for mechanized services despite increasing wage rates. This study analyzes the mechanization process of rice farmers in the Mwea Irrigation Scheme, Kenya. The Mwea Irrigation Scheme is the most advanced rice production area in SSA, with farmers familiar with improved rice cultivation practices, well-functioning input credit markets, and millers adopting modern milling technologies, enabling local rice to compete with imported Asian rice. Analyzing original data collected in 2011, 2016, and 2018, we found that most farmers in Mwea implemented rotavation using tractor services provided by farmers’ cooperatives, while they implemented leveling using draft animals. Non-cooperative members reduced tractor use and adopted draft animals to implement both harrowing and leveling, implying the importance of a well-developed mechanization service market.
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Oyeagu, Chika E., and Francis B. Lewu. "Why Agricultural Water Productivity Matters: A Review." In Enhancing Water and Food Security Through Improved Agricultural Water Productivity. Springer Nature Singapore, 2025. https://doi.org/10.1007/978-981-96-1848-4_2.
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Abstract Due to the increasing population, economic development, and climate change, providing food and water security requires significant changes in the technologies that propel present-day water management. Irrigation is the largest and most inefficient water user, and there is an expectation that even small improvements in agricultural water productivity will enhance water security. Increasing water productivity is a novel practice needed to improved water management for sustainable agriculture, food security and healthy ecosystem. The explanation of water productivity involves the quantity of agricultural output per unit of water loss, which can be applied to crops, livestock and aquaculture. This chapter reviews the challenges and opportunities for enhancing water productivity in socially equitable and sustainable ways. Water productivity can be improved in irrigated and rainfed cropping systems by choosing a well-adopted crop type, reducing unproductive water losses, and maintaining healthy, vigorous growing crops through optimized water, nutrient, and agronomic management. Livestock water productivity can be increased through improved feed management and animal husbandry, reduced animal mortality, appropriate livestock watering, and sustainable grazing management. In aquaculture systems, most water is lost indirectly for feed production via seepage and evaporation from water bodies, and through polluted water discharge, and efforts to improve water productivity should be directed at minimizing those losses. The review also identifies different strategies for improving agricultural water productivity and biophysical and climate change influence on agricultural water productivity. Effort has been made to address why agricultural water productivity matters.
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Behboudian, M. H., J. Marsal, J. Girona, and G. Lopez. "Quality and Yield Responses of Deciduous Fruits to Reduce Irrigation." In Horticultural Reviews. John Wiley & Sons, Inc., 2011. http://dx.doi.org/10.1002/9780470872376.ch4.
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Aguirre, T., I. Misar, J. Moeglen, and N. Daly. "Bituminous geomembranes (BGM) to reduce water losses in irrigation canals." In Geosynthetics: Leading the Way to a Resilient Planet. CRC Press, 2023. http://dx.doi.org/10.1201/9781003386889-215.
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Popoola, Kehinde Olayinka, Anne Jerneck, and Sunday Adesola Ajayi. "Climate Variability and Rural Livelihood Security: Impacts and Implications." In African Handbook of Climate Change Adaptation. Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-45106-6_200.
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AbstractIn a typical Nigerian village, the majority of the population comprises old people who are mostly economically unproductive due to reduced or loss of physical strength brought about by ageing and ill health. Many of these rural old people still work, and do so outside the formal sector, and are particularly susceptible to the effects of climate variability and change. Few studies have reported on climate change and the rural aged and there is a research gap as regards rural elderly peoples’ perception of climate variability impact on them. Since little is known about their perception of climate variability impacts and implications on the rural aged especially in relation to their livelihood activities in Sub-Saharan Africa, this chapter therefore examined the impact of climate variability on the livelihood security of the rural aged in different ecological zones of Nigeria.Both qualitative and quantitative methods were used for data collection. Qualitative data were obtained through interviews with four aged and four aged women selected purposively in each rural community and analyzed using Content Analysis Method. Quantitative data were obtained through structured questionnaire administered to an aged male and an aged female population available in selected houses (the aged are people 60 years and over in age) in selected rural communities in selected ecological zones of Nigeria. Where there was no combination of the two (aged men and aged women), either of the two was also sufficient.It was discovered that the ageds’ experiences of climate variability impact relate to the prevailing climate variability characteristic of each ecological zones. The impact on their livelihood in these zones is seen in terms of livestock death, lack of pastures for herds, scarcity of water, pest invasion, delayed planting crop failure, need for irrigation, water logging, drowning of small animals, human and animal illness. This means that planning decisions related to climate change issues should take cognizance of the views of the aged populations especially of those residing in rural areas as they are the most affected by the impact.
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Zhang, Pingchuan, Sijie Wang, Xiaowen Li, et al. "Orchard Energy Management to Improve Fruit Quality Based on the Internet of Things." In Proceeding of 2021 International Conference on Wireless Communications, Networking and Applications. Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-2456-9_68.
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AbstractThe crop growth is an energy conversion process, and energy management has an important impact on the quality and yield of crop products. As IoT (the Internet of Things) is widely used in agriculture, for example, orchard IoT is often used to realize water-saving irrigation, this paper innovatively proposes a scheme to improve fruit quality by using IoT to realize orchard energy management. The designed Internet of things, in addition to the usual orchard environmental parameters and water-saving irrigation, can further adjust the temperature difference between day and night according to the local temperature, that is, by spraying low-temperature water mist at 16 ℃ to reduce the ambient temperature of the orchard at night, creating an environment conducive to the conversion of carbohydrate into sugar. The experiment in peach orchard shows that the orchard energy management method based on Internet of Things works effectively, which can reduce the peach orchard temperature to 20° at night in summer, which is beneficial to improve the peach fruit sweetness.
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"REDUCED DEMAND IRRIGATION SCHEDULING UNDER CONSTRAINT OF THE IRRIGATION METHOD." In Water and the Environment. CRC Press, 2003. http://dx.doi.org/10.1201/9781482272086-58.
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Sindhu, V. K., A. S. Brar, Norah Johal, Priyanka Sahoo, and Harjeet Kaur. "INNOVATIONS IN IRRIGATION AUTOMATION FOR SUSTAINABLE AGRICULTURE." In Futuristic Trends in Robotics & Automation Volume 3, Book 1. Iterative International Publisher, Selfypage Developers Pvt Ltd, 2024. http://dx.doi.org/10.58532/v3bbra1p4ch1.
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Irrigation plays a critical role in global food security, with over 70% of water usage dedicated to irrigating crops. Developing countries heavily rely on irrigation, accounting for over 80% of freshwater withdrawals, and improving water use efficiency in these regions could significantly conserve water resources. With the world's population projected to increase, particularly in South Asia, where India alone will account for a substantial portion, the demand for irrigation water is expected to rise, emphasizing the need for sustainable practices to meet future food production needs while addressing the challenges posed by climate change. The implementation of automated irrigation systems holds promise in addressing various challenges associated with irrigation. While automated irrigation has been widely used in different water distribution systems, its adoption in flood irrigation systems has been limited. This chapter aims to assess the current state and advancements in automated irrigation for crops, including its components and technologies. Additionally, it identifies potential factors that may impede the widespread adoption of existing systems and highlights the need for additional features in automated irrigation systems to maximize water savings in commercial crop production. To fully realize the socio-economic and environmental paybacks of automation, further research is obligatory to determine optimal parameters for irrigation scheduling. Resolving the research and technical gaps could facilitate the extensive adoption of automated irrigation practices, leading to improved water use efficiency, crop productivity, and profitability, reduced labor requirements, and minimized environmental impact.
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Jha, Ayushi, Simranpreet Kaur, Sadhani Kumari, and Mahima Sharma. "IOT BASED IRRIGATION MANAGEMENT SYSTEM." In Futuristic Trends in Agriculture Engineering & Food Sciences Volume 2 Book 9. Iterative International Publishers, Selfypage Developers Pvt Ltd, 2023. http://dx.doi.org/10.58532/v2bs9ch15.
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Agriculture is one of the major activities in developing countries to sustain the life by providing food and other essentials to the living organism. Also, agriculture is a major water consuming sector in which irrigation practice utilizes major percentage of water of about 70-80 percent. Thus, a method is required to use water in agriculture effectively. In comparison to conventional methods, the modern irrigation system significantly reduces the amount of water used and assists irrigation scheduling mainly in some crops, like rice, require varying amounts of water as they develop. This chapter discusses about IoT based irrigation management system and suggests automating irrigation through the use of a smart phone that measures moisture content and periodically communicates data to a microcontroller via a connectivity unit. The microcontroller makes irrigation decisions and notifies the farmer through text message when the field is in good condition. This technology will raise agricultural yield because it is non-contact and non-invasive property. It can also help farmers decide how much irrigation to use in order to enhance crop cultivation. By utilizing this new age agricultural technologies, the crop's overall production costs will be reduced and also saves the time by decreasing the need for human i
Conference papers on the topic "Reduced irrigation"
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Samfiraa, Ionel, Nicolae Marinel Horablaga, Saida Feier David, Veronica Sarateanu, and Elena Mirela Samfira. "POPLAR BIOMASS PRODUCTION IN TEMPERATE-CONTINENTAL PLAIN CONDITIONS." In 24th SGEM International Multidisciplinary Scientific GeoConference 2024. STEF92 Technology, 2024. https://doi.org/10.5593/sgem2024v/4.2/s16.06.
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Biomass is the first form of energy used by man at the same time with the discovery of fire, means all the products of animal and vegetable origin used in present in the production of energy. Actually, the biomass approximately half (44-65 %) of the total renewable energy sources used in the EU, and occupies a third place as a primary energy source in the world, after coal and oil. At the same time represents a sustainable alternative to reduce carbon emissions. The experimental territory is located in the middle of the low plain area of the Western Plain in Romania at an altitude of 80-90 meters. The climate is temperate-continental, with Mediterranean and oceanic influences, the average annual temperatures are 10-11 degrees Celsius. Precipitation shows some particularities, but on average the average annual amounts recorded are 500-600 mm. The purpose of the present study, the production potential of a poplar energy crop located in the low plain in Romania. A pure culture was analyzed in terms of biomass production over a 6-year production cycle under optimal culture conditions. Development parameters such as survival rate and plant height were analyzed, as well as production parameters such as dry matter content and biomass production. Also, a culture technology characterized by low energy consumption was used, i.e. without the application of irrigation, or fertilization. Finally, the study wants to convince that the energy poplar culture is particularly productive in a 6-year production cycle and also constitutes a very good alternative to using agricultural land unsuitable for other crops.
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"Screening of Tomato Genotypes for Tolerance of Reduced Irrigation." In June 19-21, 2019 Lisbon (Portugal). Excellence in Research & Innovation, 2019. http://dx.doi.org/10.17758/eirai5.f0619209.
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Burke, John J. "Genetic Programming of Crops to Sustain or Increase Yields under Reduced Irrigation." In World Water and Environmental Resources Congress 2005. American Society of Civil Engineers, 2005. http://dx.doi.org/10.1061/40792(173)532.
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Senyigit, Ulas, Haq Nawaz, Vilda Grybauskiene, Ilknur Akguen, Cengiz Turkay, and Veli Demirbilek. "Sustainable water management in maize farming: comparison of deficit irrigation approaches." In 24th International Scientific Conference Engineering for Rural Development. Latvia University of Life Sciences and Technologies, Faculty of Engineering and Information Technologies, 2025. https://doi.org/10.22616/erdev.2025.24.tf063.
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In the face of global water scarcity and the increasing demand for agricultural production, efficient water management practices have become crucial, especially in water-intensive crops like maize. This study is important as it addresses the pressing need to improve water optimization in maize. The objective of this study was to evaluate the impact of using both modern and conventional deficit irrigation method strategies on maize production. In this experiment we evaluated conventional irrigation as 100%, 75%, 50% and 25% along with the modern alternative technique PRD (partial root zone irrigation) with one right and one left side irrigation (50% deficit) of the cultivated maize crop. Based on analysis of the results, the highest yield and yield contributing traits were obtained from 100% irrigation followed by 75% irrigation which was statistically in line with PRD. Experimental plots applied with 100% irrigation resulted in 7211 kg·ha-1 grain yield, 75% irrigation 5411 kg·ha-1, while PRD plots 5122 kg·ha-1. Likewise, 50% irrigation resulted in 3955 kg·ha-1, while 25% irrigation resulted in 2123 kg·ha-1. This study shows that partial root zone irrigation (PRD) and 75% irrigation can achieve high maize yields with reduced water use compared to full irrigation. While lower irrigation levels (25% and 50%) significantly decreased yields, PRD offers a sustainable solution for conserving water without compromising crop production.
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Wiens, A. Josh, and Amos G. Winter. "A Novel Pressure Compensating Valve for Low-Cost Drip Irrigation." In ASME 2014 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/detc2014-35131.
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This paper presents a novel pressure-compensating flow restrictor for low-cost/low-pressure drip irrigation systems. There are nearly one billion subsistence farmers in the developing world who lack the resources and opportunities to rise out of poverty. Irrigation is an effective development strategy for this population, enabling farmers to increase crop yields and grow more lucrative plant varieties. Unfortunately, as a large fraction of subsistence farmers live off the electrical grid, the capital cost of solar or diesel powered irrigation systems makes them unobtainable. This cost could be drastically reduced by altering drip irrigation systems to operate at a decreased pressure such that lower pumping power is required. The work presented here aims to accomplish this by designing a drip emitter that operates at 0.1 bar, 1/10 the pressure of current products, while also providing pressure-compensation to uniformly distribute flow over a field. Our proposed pressure compensating solution is inspired by the resonating nozzle of a deflating balloon. First, a reduced order model is developed to understand the physical principles which drive the cyclic collapse of the balloon nozzle. We then apply this understanding to propose a pressure compensating emitter consisting of compliant tube in series with a rigid diffuser. A scaling analysis is performed to determine the ideal geometry of the system and the reduced order model is applied to demonstrate that the proposed design is capable of pressure compensation in the required operation range. Preliminary experiments demonstrating the collapse effect are presented, along with initial work to translate the concept to a robust physical device.
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"Reduced Runoff from Center Pivot and Linear Move irrigation Systems with Off-Set Booms (Boombacks)." In 2015 ASABE International Meeting. American Society of Agricultural and Biological Engineers, 2015. http://dx.doi.org/10.13031/aim.20152188723.
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Zimoch, Pawel J., Eliott Tixier, Abhijit Joshi, A. E. Hosoi, and Amos G. Winter. "Bio-Inspired, Low-Cost, Self-Regulating Valves for Drip Irrigation in Developing Countries." In ASME 2013 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/detc2013-12495.
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We use nonlinear behavior of thin-walled structures — an approach inspired by biological systems (the human airway, for example) — to address one of the most important problems facing subsistence farmers in developing countries: lack of access to inexpensive, water-efficient irrigation systems. An effective way of delivering water to crops is through a network of emitters, with up to 85% of the water delivered being absorbed by plants. However, of the 140 million hectares of cropped land in India alone, only 61 million are irrigated and just 5 million through drip irrigation. This is, in part, due to the relatively high cost of drip irrigation. The main cost comes from the requirement to pump the water at relatively high pressure (>1bar), to minimize the effect of uneven terrain and viscous losses in the network, and to ensure that each plant receives the same amount of water. Using a prototype, we demonstrate that the pressure required to drive the system can be reduced significantly by using thin-walled structures to design emitters with completely passive self-regulation that activates at approximately 0.1bar. This reduction in driving pressure could help bring the price of drip irrigation systems from several thousand dollars to approximately $300, which is within reach of small-scale farmers. Using order-of-magnitude calculations, we show that due to increased sensitivity of the proposed design to the applied pressure differential, a pressure compensating valve for drip irrigation could be built without using costly silicone membranes.
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Wang, Xinkun, and Junhong Li. "Numerical Calculation of Triangle Circulation Drip Irrigation Emitters." In ASME 2010 8th International Conference on Nanochannels, Microchannels, and Minichannels collocated with 3rd Joint US-European Fluids Engineering Summer Meeting. ASMEDC, 2010. http://dx.doi.org/10.1115/fedsm-icnmm2010-30581.
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Based on the hydraulic characteristics of triangle circulation, sudden-expansion pipe and sudden contraction pipe, Construct a drip irrigation emitter with strong turbulent flow, large over-current cross-section and strong anti-clogging ability. Triangular circulation flow path emitters for the key structural parameters for the factors, application of computer numerical fluid dynamics CFD software FLUENT6.3, simulate triangular circulation flow channel structure, analyze the influence of various structural parameters on hydraulic performance of emitters, flow index, flow rate and the anti-clogging ability. The results show that increase unit cusp, unit chamfer, the flow index increased, but the effect to varying degrees; inlet dimension increase, flow index reduced; flow channel depth and flow channel width increases, the discharge increases. Increase unit cusp, unit chamfered, can improve the anti-clogging performance of emitters. Based on the above results, to design an emitter structure with good performance, and its numerical simulation analysis, the flow index, flow rate and anti-clogging ability have met the requirements of drip irrigation. Provide a theoretical basis for the triangle circulation emitter structure design and quantitative analysis. The research has a positive meaning for energy conservation.
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Greenlee, Alison, Timothy Murray, Victor Lesniewski, Mark Jeunnette, and Amos G. Winter. "Design and Testing of a Low-Cost and Low-Maintenance Drip Irrigation Filtration System for Micro-Irrigation in Developing Countries." In ASME 2014 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/detc2014-35351.
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The cylindrical filters presently used in <1000 m2 drip irrigation systems are frequently clogged, increasing pressure loss and lowering the flow rate through the filters. This work investigates the mechanisms for this clogging and proposes an alternative filtration design that would enable both more reliable and lower maintenance filtering. This proposed system is compatible with existing drip irrigation systems and could be made inexpensively with plastic bottle manufacturing equipment. To compare the proposed design to off-the-shelf options, a drip irrigation test setup was built to measure the pressure loss across different filters as particles accumulated. These experiments confirmed that pleated cartridge filters, with high effective surface area, incurred lower pressure losses than cylindrical filters. These tests revealed that the greatest reason for clogged performance was that filtered particles (not the cartridge filter itself) eventually restricted the flow of water through the system. This inspired the redesign of the filter housing such that the housing extended far below the filter, providing a catch basin away from the filter for the particles to settle. Fixing the filter independently of the bottom casing significantly improved the overall performance of the filtration system, reduced the maintenance requirement necessary from the user, and would enable inexpensive manufacturing via blow molding. This paper experimentally demonstrates that the cartridge filter inside the redesigned housing can filter out over 2 kg of sand while maintaining less than a .03 bar pressure drop across the filter at a flow rate of 25 l/s.
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Tupajić, Ivan, Đorđe Moravčević, Marija Ćosić, et al. "EFFECT OF SOWING TIME AND IRRIGATION REGIMES ON YIELD COMPONENTS OF SWEET CORN." In 12. JEEP INTERNATIONAL SCIENTIFIC AGRIBUSINESS CONFERENCE, MAK 2025 – KOPAONIK. Association science and business center WORLD; Institute for plant protection and environmen, 2025. https://doi.org/10.46793/mak2025.186t.
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The objective of this study was to examine the feasibility of cultivating sweet corn in the agroecological conditions of the Šumadija region. During 2022/23, the most widespread hybrid of sweet corn on the Serbian market, ‘Enterprise,’ was tested. Two irrigation regimes were applied (full and reduced to 50%) along with a control treatment (natural moisture conditions). Harvest and cob analysis were conducted on average 22-25 days after pollination. Statistically significant higher values for the studied parameters were measured in the irrigated treatments across both sowing dates.
Reports on the topic "Reduced irrigation"
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MacDonald, James D., Aharon Abeliovich, Manuel C. Lagunas-Solar, David Faiman, and John Kabshima. Treatment of Irrigation Effluent Water to Reduce Nitrogenous Contaminants and Plant Pathogens. United States Department of Agriculture, 1993. http://dx.doi.org/10.32747/1993.7568092.bard.
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The contamination of surface and subterranean drinking water supplies with nitrogen-laden agricultural wastewater is a problem of increasing concern in the U.S. and Israel. Through this research, we found that bacteria could utilize common organic wastes (e.g. paper, straw, cotton) as carbon sources under anaerobic conditions, and reduce nitrate concentrations in wastewater to safe levels. Two species of bacteria, Cellulomonas uda and a Comamonas sp., were required for dentitrification. Celulomonas uda degraded cellulose and reduced nitrate to nitrite. In addition, it excreted soluble organic carbon needed as a food source by the Comamonas sp. for completion of denitrification. We also found that recirculated irrigation water contains substantial amounts of fungal inoculum, and that irrigating healthy plants with such water leads to significant levels of root infection. Water can be disinfected with UV, but our experiments showed that Hg-vapor lamps do not possess sufficient energy to kill spores in wastewater containing dissolved organics. Excimer lasers and Xenon flashlamps do possess the needed power levels, but only the laser had a high enough repetition rate to reliably treat large volumes of water. Ozone was highly efficacious, but it's use as a water treatment is probably best suited to moderate or low volume irrigation systems. This research provides critical data needed for the design of effective water denitrification and/or pathogen disinfection systems for different growing operations.
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Banin, Amos, Joseph Stucki, and Joel Kostka. Redox Processes in Soils Irrigated with Reclaimed Sewage Effluents: Field Cycles and Basic Mechanism. United States Department of Agriculture, 2004. http://dx.doi.org/10.32747/2004.7695870.bard.
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The overall objectives of the project were: (a) To measure and study in situ the effect of irrigation with reclaimed sewage effluents on redox processes and related chemical dynamics in soil profiles of agricultural fields. (b) To study under controlled conditions the kinetics and equilibrium states of selected processes that affect redox conditions in field soils or that are effected by them. Specifically, these include the effects on heavy metals sorption and desorption, and the effect on pesticide degradation. On the basis of the initial results from the field study, increased effort was devoted to clarifying and quantifying the effects of plants and water regime on the soil's redox potential while the study of heavy metals sorption was limited. The use of reclaimed sewage effluents as agricultural irrigation water is increasing at a significant rate. The relatively high levels of suspended and, especially, dissolved organic matter and nitrogen in effluents may affect the redox regime in field soils irrigated with them. In turn, the changes in redox regime may affect, among other parameters, the organic matter and nitrogen dynamics of the root zone and trace organic decomposition processes. Detailed data of the redox potential regime in field plots is lacking, and the detailed mechanisms of its control are obscure and not quantified. The study established the feasibility of long-term, non-disturbing monitoring of redox potential regime in field soils. This may enable to manage soil redox under conditions of continued inputs of wastewater. The importance of controlling the degree of wastewater treatment, particularly of adding ultrafiltration steps and/or tertiary treatment, may be assessed based on these and similar results. Low redox potential was measured in a field site (Site A, KibutzGivat Brenner), that has been irrigated with effluents for 30 years and was used for 15 years for continuous commercial sod production. A permanently reduced horizon (Time weighted averaged pe= 0.33±3.0) was found in this site at the 15 cm depth throughout the measurement period of 10 months. A drastic cultivation intervention, involving prolonged drying and deep plowing operations may be required to reclaim such soils. Site B, characterized by a loamy texture, irrigated with tap water for about 20 years was oxidized (Time weighted average pe=8.1±1.0) throughout the measurement period. Iron in the solid phases of the Givat Brenner soils is chemically-reduced by irrigation. Reduced Fe in these soils causes a change in reactivity toward the pesticide oxamyl, which has been determined to be both cytotoxic and genotoxic to mammalian cells. Reaction of oxamyl with reduced-Fe clay minerals dramatically decreases its cytotoxicity and genotoxicity to mammalian cells. Some other pesticides are affected in the same manner, whereas others are affected in the opposite direction (become more cyto- and genotoxic). Iron-reducing bacteria (FeRB) are abundant in the Givat Brenner soils. FeRB are capable of coupling the oxidation of small molecular weight carbon compounds (fermentation products) to the respiration of iron under anoxic conditions, such as those that occur under flooded soil conditions. FeRB from these soils utilize a variety of Fe forms, including Fe-containing clay minerals, as the sole electron acceptor. Daily cycles of the soil redox potential were discovered and documented in controlled-conditions lysimeter experiments. In the oxic range (pe=12-8) soil redox potential cycling is attributed to the effect of the daily temperature cycle on the equilibrium constant of the oxygenation reaction of H⁺ to form H₂O, and is observed under both effluent and freshwater irrigation. The presence of plants affects considerably the redox potential regime of soils. Redox potential cycling coupled to the irrigation cycles is observed when the soil becomes anoxic and the redox potential is controlled by the Fe(III)/Fe(II) redox couple. This is particularly seen when plants are grown. Re-oxidation of the soil after soil drying at the end of an irrigation cycle is affected to some degree by the water quality. Surprisingly, the results suggest that under certain conditions recovery is less pronounced in the freshwater irrigated soils.
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Agassi, Menahem, Michael J. Singer, Eyal Ben-Dor, et al. Developing Remote Sensing Based-Techniques for the Evaluation of Soil Infiltration Rate and Surface Roughness. United States Department of Agriculture, 2001. http://dx.doi.org/10.32747/2001.7586479.bard.
Full textAbstract:
The objective of this one-year project was to show whether a significant correlation can be established between the decreasing infiltration rate of the soil, during simulated rainstorm, and a following increase in the reflectance of the crusting soil. The project was supposed to be conducted under laboratory conditions, using at least three types of soils from each country. The general goal of this work was to develop a method for measuring the soil infiltration rate in-situ, solely from the reflectance readings, using a spectrometer. Loss of rain and irrigation water from cultivated fields is a matter of great concern, especially in arid, semi-arid regions, e.g. much of Israel and vast area in US, where water is a limiting factor for crop production. A major reason for runoff of rain and overhead irrigation water is the structural crust that is generated over a bare soils surface during rainfall or overhead irrigation events and reduces its infiltration rate (IR), considerably. IR data is essential for predicting the amount of percolating rainwater and runoff. Available information on in situ infiltration rate and crust strength is necessary for the farmers to consider: when it is necessary to cultivate for breaking the soil crust, crust strength and seedlings emergence, precision farming, etc. To date, soil IR is measured in the laboratory and in small-scale field plots, using rainfall simulators. This method is tedious and consumes considerable resources. Therefore, an available, non-destructive-in situ methods for soil IR and soil crusting levels evaluations, are essential for the verification of infiltration and runoff models and the evaluation of the amount of available water in the soil. In this research, soil samples from the US and Israel were subjected to simulated rainstorms of increasing levels of cumulative energies, during which IR (crusting levels) were measured. The soils from the US were studied simultaneously in the US and in Israel in order to compare the effect of the methodology on the results. The soil surface reflectance was remotely measured, using laboratory and portable spectrometers in the VIS-NIR and SWIR spectral region (0.4-2.5mm). A correlation coefficient spectra in which the wavelength, consisting of the higher correlation, was selected to hold the highest linear correlation between the spectroscopy and the infiltration rate. There does not appear to be a single wavelength that will be best for all soils. The results with the six soils in both countries indeed showed that there is a significant correlation between the infiltration rate of crusted soils and their reflectance values. Regarding the wavelength with the highest correlation for each soil, it is likely that either a combined analysis with more then one wavelength or several "best" wavelengths will be found that will provide useful data on soil surface condition and infiltration rate. The product of this work will serve as a model for predicting infiltration rate and crusting levels solely from the reflectance readings. Developing the aforementioned methodologies will allow increased utilization of rain and irrigation water, reduced runoff, floods and soil erosion hazards, reduced seedlings emergence problems and increased plants stand and yields.
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Friedler, Eran, and Karl G. Linden. Distributed UV LEDs for combined control of fouling of drip emitters and disinfection during irrigation with reclaimed wastewater effluent. United States-Israel Binational Agricultural Research and Development Fund, 2022. http://dx.doi.org/10.32747/2022.8134144.bard.
Full textAbstract:
Irrigating crops with reclaimed wastewater, replacing potable water, using drip irrigation has become more common as demands on water supplies have increased. Because of the quality characteristics of treated wastewater, the small size and geometry of drip emitters, and flow characteristics though the emitters, systems can become clogged for physical and biological reasons. Emitters clogging reduces flow and increases the variability of flows between emitters that can lead to crops water stress and thus reduce crop yield. Clogged systems require more energy or more labor- and chemical-intensive maintenance and cleaning, such as with chlorine. Ultraviolet (UV) irradiation, and specifically UV-C (200-300 nm) light emitting diodes (LEDs) have great promise for disinfection and biofouling prevention in irrigation water systems. LEDs are particularly well-suited for decentralized use in drip irrigation systems due to their small size, robust construction, low power requirements, long life, and intermittent operation capability. The main goal of this research was to study and develop UV-LED irradiation technology for reducing biofouling of drip irrigation fed by treated effluent, and to explore whether locating the UV-LEDs along the irrigation line as an integral part of the system could be advantageous.
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Hovav, Ran, Peggy Ozias-Akins, and Scott A. Jackson. The genetics of pod-filling in peanut under water-limiting conditions. United States Department of Agriculture, 2012. http://dx.doi.org/10.32747/2012.7597923.bard.
Full textAbstract:
Pod-filling, an important yield-determining stage is strongly influenced by water stress. This is particularly true for peanut (Arachishypogaea), wherein pods are developed underground and are directly affected by the water condition. Pod-filling in peanut has a significant genetic component as well, since genotypes are considerably varied in their pod-fill (PF) and seed-fill (SF) potential. The goals of this research were to: Examine the effects of genotype, irrigation, and genotype X irrigation on PF and SF. Detect global changes in mRNA and metabolites levels that accompany PF and SF. Explore the response of the duplicate peanut pod transcriptome to drought stress. Study how entire duplicated PF regulatory processes are networked within a polyploid organism. Discover locus-specific SNP markers and map pod quality traits under different environments. The research included genotypes and segregating populations from Israel and US that are varied in PF, SF and their tolerance to water deficit. Initially, an extensive field trial was conducted to investigate the effects of genotype, irrigation, and genotype X irrigation on PF and SF. Significant irrigation and genotypic effect was observed for the two main PF related traits, "seed ratio" and "dead-end ratio", demonstrating that reduction in irrigation directly influences the developing pods as a result of low water potential. Although the Irrigation × Genotype interaction was not statistically significant, one genotype (line 53) was found to be more sensitive to low irrigation treatments. Two RNAseq studies were simultaneously conducted in IL and the USA to characterize expression changes that accompany shell ("source") and seed ("sink") biogenesis in peanut. Both studies showed that SF and PF processes are very dynamic and undergo very rapid change in the accumulation of RNA, nutrients, and oil. Some genotypes differ in transcript accumulation rates, which can explain their difference in SF and PF potential; like cvHanoch that was found to be more enriched than line 53 in processes involving the generation of metabolites and energy at the beginning of seed development. Interestingly, an opposite situation was found in pericarp development, wherein rapid cell wall maturation processes were up-regulated in line 53. Although no significant effect was found for the irrigation level on seed transcriptome in general, and particularly on subgenomic assignment (that was found almost comparable to a 1:1 for A- and B- subgenomes), more specific homoeologous expression changes associated with particular biosynthesis pathways were found. For example, some significant A- and B- biases were observed in particular parts of the oil related gene expression network and several candidate genes with potential influence on oil content and SF were further examined. Substation achievement of the current program was the development and application of new SNP detection and mapping methods for peanut. Two major efforts on this direction were performed. In IL, a GBS approach was developed to map pod quality traits on Hanoch X 53 F2/F3 generations. Although the GBS approach was found to be less effective for our genetic system, it still succeeded to find significant mapping locations for several traits like testa color (linkage A10), number of seeds/pods (A5) and pod wart resistance (B7). In the USA, a SNP array was developed and applied for peanut, which is based on whole genome re-sequencing of 20 genotypes. This chip was used to map pod quality related traits in a Tifrunner x NC3033 RIL population. It was phenotyped for three years, including a new x-ray method to phenotype seed-fill and seed density. The total map size was 1229.7 cM with 1320 markers assigned. Based on this linkage map, 21 QTLs were identified for the traits 16/64 weight, kernel percentage, seed and pod weight, double pod and pod area. Collectively, this research serves as the first fundamental effort in peanut for understanding the PF and SF components, as a whole, and as influenced by the irrigation level. Results of the proposed study will also generate information and materials that will benefit peanut breeding by facilitating selection for reduced linkage drag during introgression of disease resistance traits into elite cultivars. BARD Report - Project4540 Page 2 of 10
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Gavin, Greg, Paul Inkenbrandt, Trevor Schlossnagle, and Rebecca Molinari. Groundwater of Pahvant Valley, Millard County, Utah. Utah Geological Survey, 2024. http://dx.doi.org/10.34191/ss-173.
Full textAbstract:
Pahvant Valley, located in Millard County, Utah, encompasses 1610 square miles and includes several small towns, agricultural districts, hot springs, and biologically important wetlands, all heavily reliant on groundwater. This study, conducted by the Utah Geological Survey during 2022 and 2023, aims to define Pahvant Valley’s water recharge and discharge estimates, characterize its primary hydrogeologic units, and describe groundwater recharge and discharge areas. The research includes the collection of groundwater and surface water samples to estimate flow paths, sources of recharge and discharge, and residence times. Additionally, a water-level campaign was conducted in early March 2022 to create an updated potentiometric surface map for the region. Pahvant Valley’s groundwater system comprises three main aquifers: the valley-fill aquifer, the volcanic aquifer of the Tabernacle Hill and Ice Springs lava flows, and the Black Rock Desert volcanics. For this study, we delineated these aquifers into three conceptual groundwater zones based on hydrogeologic, geochemical, and potentiometric characteristics. Results of this study indicate significant groundwater level declines, particularly in agricultural areas, driven by overextraction and reduced recharge. Groundwater levels have declined by an average of 26 feet since 1986 and some areas have experienced declines of up to 160 feet. The study emphasizes the crucial role of streamflow from the Pahvant Range in recharging the valley-fill aquifer, with stable isotope and chemical analyses confirming that stream discharge significantly contributes to groundwater recharge. Additionally, groundwater quality varies across the valley and increased total dissolved solids could affect water usability in some areas. The analysis of irrigation practices reveals a significant shift in the early 1990s from flood irrigation to pivot irrigation, which led to increased and more consistent crop density and health, as indicated by Normalized Difference Vegetation Index (NDVI) data. From 1992 to 2021, NDVI values rose substantially in both magnitude and duration, reflecting higher crop yields over time. This increase in crop density and vitality resulted in higher evapotranspiration per acre, while the extended duration of greenness demonstrated stable yields regardless of surface water availability. As irrigation shifted from surface water to groundwater sources, numerous high-capacity wells were established to meet demand. Consequently, groundwater pumping in areas no longer reliant on surface water led to declines in groundwater elevations. These decreases in groundwater levels have been linked to land subsidence, with Interferometric Synthetic Aperture Radar (InSAR) analysis detecting up to 5 inches of ground deformation in the Meadow area between 2014 and 2022, closely associated with changes in groundwater levels. This study underscores the critical balance between groundwater extraction and recharge, the effects of irrigation practices on water use, and the importance of continuous monitoring and management to ensure sustainable groundwater resources. The findings highlight the need for sustainable groundwater management practices to maintain agricultural productivity and ecological health in Pahvant Valley.
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Miyamoto, Seiichi, and Rami Keren. Improving Efficiency of Reclamation of Sodium-Affected Soils. United States Department of Agriculture, 2000. http://dx.doi.org/10.32747/2000.7570569.bard.
Full textAbstract:
Sodium affected soils, along with salt-affected soils, are distributed widely in irrigated areas of the arid and semi-arid region of the world. Some of these soils can and must be reclaimed to meet the increasing demand for food, and existing irrigated lands must be managed to reduce salinization and alkalization associated with deteriorating irrigation water quality. This project was conducted for examining ways to reduce the use of chemical amendments and large quantities of leaching water for reclaiming sodic soils or for preventing soil sodification, We hypothesized that sodicity of calcareous soils irrigated with moderately sodic irrigation water can be controlled by maximizing dissolution of soil CaCO3. The work performed in Israel has shown that dissolution of CaCO3 can be enhanced by elevating the CO2 partial pressure in soils, and by increasing pore water velocity. The concentration of Ca in pore water was at an order of 1.5 mmolc L-1 at a CO2 partial pressure of 5 kPa, which is sufficient to maintain SAR below 4 at salinity of irrigation water of 0.5 dS m-1 or less. Incorporation of crop residue at a flesh weight of 100 Mg ha-1 reduced the exchangeable Na percentage from 19 to 5%, while it remained 14% without crop residue application These findings indicate a possibility of preventing soil sodification with appropriate crop rotation and residue management without chemical amendments, provided that soils remain permeable. In the case of highly sodic soils, dissolution of CaCO3 alone is usually insufficient to maintain soil permeability during initial leaching. We examined the effect of salinity and sodicity on water infiltration, then developed a way to estimate the amendments required on the basis of water infiltration and drainage characteristics, rather than the traditional idea of reducing the exchangeable Na percentage to a pre-fixed value. Initial indications from soil column and lysimeter study are that the proposed method provides realistic estimates of amendment requirements. We further hypothesized that cultivation of salt-tolerant plants with water of elevated salinity can enhance reclamation of severely Na-affected soils primarily through improved water infiltration and increased dissolution of CaCO3 through respiration. An outdoor lysimeter experiment using two saline sodic Entisols sodded with saltgrass for two seasons did not necessarily support this hypothesis. While there was an evidence of increased removal of the exchangeable Na originally present in the soils, the final salinity and sodicity measured were lowest without sod, and highest when sodded. High transpiration rates, coupled with low permeability and/or inadequate leaching seemed to have offset the potential benefits of increased CaCO3 dissolution and subsequent removal of exchangeable Na. Although vegetative means of reclaiming sodic soils had been reported to be effective in sandy soils with sufficient permeability, additional study is needed for its use in saline sodic soils under the high evaporative demand. The use of cool season grass after initial salt leaching with CaCl2 should be explored. Results obtained from this project have several potential applications, which include the use of crop residues for maintaining sodium balance, the use of CaCl2 for initial leaching of poorly permeable clayey sodic soils, and appraisal of sodicity effects, and appropriate rates and types of amendments required for reclamation
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Graber, Ellen R., Linda S. Lee, and M. Borisover. An Inquiry into the Phenomenon of Enhanced Transport of Pesticides Caused by Effluents. United States Department of Agriculture, 1995. http://dx.doi.org/10.32747/1995.7570559.bard.
Full textAbstract:
The objective of this collaborative research project was to determine the factors that may cause enhanced pesticide transport under effluent irrigation. For s-triazines, the potential for enhanced transport through association with effluent dissolved organic matter (OM) was shown to be small in batch and column studies and in numerical simulations. High alkalinity and pH of treated effluents increased soil-solution pH for selected soil-effluent combinations, promoting the dissolution of soil OM and mobilizing otherwise OM-retained pesticides. Evapotranspiration in column studies resulted in increased pore-water concentrations of dissolved OM and some pesticide transport enhancement with the greatest effect observed with OM-poor soils. For ionogenic pesticides, effluent-induced increases in soil-solution pH increased the mobility of pesticides with acid dissociation constants within 2 pH units of the initial soil-solution pH. Effluents high in suspended solids and/or monovalent cations resulted in blockage of soil pores reducing water-flow velocity and/or changing flow paths. Reduced flow resulted in an increase in desorption time of soil sorbed pesticides, increasing the amount available for further transport with the net effect being soil texture dependent. In terms of pesticide degradation in soils, effluents appeared to have only a minor effect for the few pesticides investigated.
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Carvalho, Helena. Land Inequality, Agricultural Productivity, and the Portuguese Agrarian Reform (1974-1976). APHES Working Paper in Economic and Social History, 2022. http://dx.doi.org/10.55462/wpaphes_a_503.
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Land reforms sacrifice property rights in the name of a fairer distribution. The trade-off they imply makes their study of interest to Economic Historians: do the benefits of reduced land inequality justify the violation of property rights? The discussion about land reforms factors in both the social and efficiency consequences of land inequality. The debate preceding the Portuguese Agrarian Reform echoes these concerns and culminated in an anti-latifundia sentiment crystallized in the legislation used to justify the land occupations of 1974 to 1976. The aim of this paper is to critically assess the efficiency arguments used to justify the occupations. Was land productivity lower in latifúndio counties? A unique dataset drawn from primary sources was specially assembled to answer this question. Through standard OLS regression, this study finds that the number of agriculture journeyman per employer landowner has a statistically significant effect on agricultural productivity after controlling for geographical and soil characteristics. It also finds that introducing literacy as a control causes the effect of land inequality to disappear leading to the conclusion that policies aimed at improving human capital would have been just as effective as a land reform. Further, this study also identifies the crop mix selected as the proximate channel of transmission. Farmers in the region with the highest levels of land inequality favoured less valuable crops, like wheat. An arid climate combined with a lack of irrigation infrastructure and wheat protectionism justify this preference.
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Friedman, Shmuel, Jon Wraith, and Dani Or. Geometrical Considerations and Interfacial Processes Affecting Electromagnetic Measurement of Soil Water Content by TDR and Remote Sensing Methods. United States Department of Agriculture, 2002. http://dx.doi.org/10.32747/2002.7580679.bard.
Full textAbstract:
Time Domain Reflectometry (TDR) and other in-situ and remote sensing dielectric methods for determining the soil water content had become standard in both research and practice in the last two decades. Limitations of existing dielectric methods in some soils, and introduction of new agricultural measurement devices or approaches based on soil dielectric properties mandate improved understanding of the relationship between the measured effective permittivity (dielectric constant) and the soil water content. Mounting evidence indicates that consideration must be given not only to the volume fractions of soil constituents, as most mixing models assume, but also to soil attributes and ambient temperature in order to reduce errors in interpreting measured effective permittivities. The major objective of the present research project was to investigate the effects of the soil geometrical attributes and interfacial processes (bound water) on the effective permittivity of the soil, and to develop a theoretical frame for improved, soil-specific effective permittivity- water content calibration curves, which are based on easily attainable soil properties. After initializing the experimental investigation of the effective permittivity - water content relationship, we realized that the first step for water content determination by the Time Domain Reflectometry (TDR) method, namely, the TDR measurement of the soil effective permittivity still requires standardization and improvement, and we also made more efforts than originally planned towards this objective. The findings of the BARD project, related to these two consequential steps involved in TDR measurement of the soil water content, are expected to improve the accuracy of soil water content determination by existing in-situ and remote sensing dielectric methods and to help evaluate new water content sensors based on soil electrical properties. A more precise water content determination is expected to result in reduced irrigation levels, a matter which is beneficial first to American and Israeli farmers, and also to hydrologists and environmentalists dealing with production and assessment of contamination hazards of this progressively more precious natural resource. The improved understanding of the way the soil geometrical attributes affect its effective permittivity is expected to contribute to our understanding and predicting capability of other, related soil transport properties such as electrical and thermal conductivity, and diffusion coefficients of solutes and gas molecules. In addition, to the originally planned research activities we also investigated other related problems and made many contributions of short and longer terms benefits. These efforts include: Developing a method and a special TDR probe for using TDR systems to determine also the soil's matric potential; Developing a methodology for utilizing the thermodielectric effect, namely, the variation of the soil's effective permittivity with temperature, to evaluate its specific surface area; Developing a simple method for characterizing particle shape by measuring the repose angle of a granular material avalanching in water; Measurements and characterization of the pore scale, saturation degree - dependent anisotropy factor for electrical and hydraulic conductivities; Studying the dielectric properties of cereal grains towards improved determination of their water content. A reliable evaluation of the soil textural attributes (e.g. the specific surface area mentioned above) and its water content is essential for intensive irrigation and fertilization processes and within extensive precision agriculture management. The findings of the present research project are expected to improve the determination of cereal grain water content by on-line dielectric methods. A precise evaluation of grain water content is essential for pricing and evaluation of drying-before-storage requirements, issues involving energy savings and commercial aspects of major economic importance to the American agriculture. The results and methodologies developed within the above mentioned side studies are expected to be beneficial to also other industrial and environmental practices requiring the water content determination and characterization of granular materials.