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Wiraguna, Edi. "Enhancement of Fixation Nitrogen in Food Legumes". Journal of Agricultural Studies 4, n.º 2 (20 de febrero de 2016): 1. http://dx.doi.org/10.5296/jas.v4i2.9065.
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Increasing the capability of nitrogen fixation in legumes is crucial because the population has been risen dramatically and predicted to be doubled by 2050. In order to feed this high population, food productivity needs to be increased. A solution to overcome this problem is through improvement of crop productivity by applying fertilizer. However, the application of fertilizer such as nitrogen is over the recommended amount and the cost is high at approximately $US 40 billion per year. Therefore, legumes are important in order to minimize the cost and enhance soil fertility through nitrogen fixation (nodulation). To achieve high nitrogen fixation, agriculture managements such as minimum tillage, breeding programs and induced mutants have been developed. In breeding program, it was found that BT-477 had high nitrogen fixation and drought tolerant based on selection among 7 common bean genotypes. Induced mutants were applied by soaking swollen seeds in EMS and resulted to higher number of nodules (10x).
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Sinclair, Thomas R. y Vincent Vadez. "The future of grain legumes in cropping systems". Crop and Pasture Science 63, n.º 6 (2012): 501. http://dx.doi.org/10.1071/cp12128.
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Grain legume production is increasing worldwide due to their use directly as human food, feed for animals, and industrial demands. Further, grain legumes have the ability to enhance the levels of nitrogen and phosphorus in cropping systems. Considering the increasing needs for human consumption of plant products and the economic constraints of applying fertiliser on cereal crops, we envision a greater role for grain legumes in cropping systems, especially in regions where accessibility and affordability of fertiliser is an issue. However, for several reasons the role of grain legumes in cropping systems has often received less emphasis than cereals. In this review, we discuss four major issues in increasing grain legume productivity and their role in overall crop production: (i) increased symbiotic nitrogen fixation capacity, (ii) increased phosphorus recovery from the soil, (iii) overcoming grain legume yield limitations, and (iv) cropping systems to take advantage of the multi-dimensional benefits of grain legumes.
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Vollmann, Johann. "Soybean versus other food grain legumes: A critical appraisal of the United Nations International Year of Pulses 2016". Die Bodenkultur: Journal of Land Management, Food and Environment 71, n.º 1 (1 de marzo de 2016): 17–24. http://dx.doi.org/10.1515/boku-2016-0002.
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SummaryThe United Nations have declared 2016 as the International Year of Pulses, which aims at communicating the various benefits of legume cropping and legume-protein-based food consumption. As the term “pulses” is inherently excluding soybean from other grain legumes, this review aims at challenging the scientific justification of this separation from both historical and crop science perspectives toward a better understanding of grain legumes and their contributions to food security. An analysis of the historical development and uses of the term “pulses” reveals that it is not used unambiguously throughout the recent scientific literature, and that the separation of soybean from other grain legumes occurred rather recently. Soybean, while being extensively used as an oilseed and animal feedstuff in some parts of the world, is an important protein crop species in other regions with a seed protein content of 40% and outstanding nutritional and food health properties as compared to most other grain legumes. Owing to similar agronomic features such as symbiotic nitrogen fixation and comparable seed protein properties, it does not seem scientifically justified to separate soybean from other food legumes. Therefore, focusing on “grain legumes” rather than “pulses” would better support food security and nutritional quality goals.
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Scheublin, Tanja R., Karyn P. Ridgway, J. Peter W. Young y Marcel G. A. van der Heijden. "Nonlegumes, Legumes, and Root Nodules Harbor Different Arbuscular Mycorrhizal Fungal Communities". Applied and Environmental Microbiology 70, n.º 10 (octubre de 2004): 6240–46. http://dx.doi.org/10.1128/aem.70.10.6240-6246.2004.
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ABSTRACT Legumes are an important plant functional group since they can form a tripartite symbiosis with nitrogen-fixing Rhizobium bacteria and phosphorus-acquiring arbuscular mycorrhizal fungi (AMF). However, not much is known about AMF community composition in legumes and their root nodules. In this study, we analyzed the AMF community composition in the roots of three nonlegumes and in the roots and root nodules of three legumes growing in a natural dune grassland. We amplified a portion of the small-subunit ribosomal DNA and analyzed it by using restriction fragment length polymorphism and direct sequencing. We found differences in AMF communities between legumes and nonlegumes and between legume roots and root nodules. Different plant species also contained different AMF communities, with different AMF diversity. One AMF sequence type was much more abundant in legumes than in nonlegumes (39 and 13%, respectively). Root nodules contained characteristic AMF communities that were different from those in legume roots, even though the communities were similar in nodules from different legume species. One AMF sequence type was found almost exclusively in root nodules. Legumes and root nodules have relatively high nitrogen concentrations and high phosphorus demands. Accordingly, the presence of legume- and nodule-related AMF can be explained by the specific nutritional requirements of legumes or by host-specific interactions among legumes, root nodules, and AMF. In summary, we found that AMF communities vary between plant functional groups (legumes and nonlegumes), between plant species, and between parts of a root system (roots and root nodules).
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Tognetti, Pedro M., Suzanne M. Prober, Selene Báez, Enrique J. Chaneton, Jennifer Firn, Anita C. Risch, Martin Schuetz et al. "Negative effects of nitrogen override positive effects of phosphorus on grassland legumes worldwide". Proceedings of the National Academy of Sciences 118, n.º 28 (6 de julio de 2021): e2023718118. http://dx.doi.org/10.1073/pnas.2023718118.
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Anthropogenic nutrient enrichment is driving global biodiversity decline and modifying ecosystem functions. Theory suggests that plant functional types that fix atmospheric nitrogen have a competitive advantage in nitrogen-poor soils, but lose this advantage with increasing nitrogen supply. By contrast, the addition of phosphorus, potassium, and other nutrients may benefit such species in low-nutrient environments by enhancing their nitrogen-fixing capacity. We present a global-scale experiment confirming these predictions for nitrogen-fixing legumes (Fabaceae) across 45 grasslands on six continents. Nitrogen addition reduced legume cover, richness, and biomass, particularly in nitrogen-poor soils, while cover of non–nitrogen-fixing plants increased. The addition of phosphorous, potassium, and other nutrients enhanced legume abundance, but did not mitigate the negative effects of nitrogen addition. Increasing nitrogen supply thus has the potential to decrease the diversity and abundance of grassland legumes worldwide regardless of the availability of other nutrients, with consequences for biodiversity, food webs, ecosystem resilience, and genetic improvement of protein-rich agricultural plant species.
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Rice, Natasha R. y Michael W. Smith. "EVALUATION OF LOW-INPUT PECAN ORCHARD FLOOR MANAGEMENT SYSTEMS". HortScience 27, n.º 6 (junio de 1992): 638c—638. http://dx.doi.org/10.21273/hortsci.27.6.638c.
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Legume ground covers in pecan orchards can reduce nitrogen inputs and increase beneficial insects. Preliminary data indicate that certain legumes can supply over 100 kg·ha-1 N. Additionally, certain legumes have high aphid populations which attract beneficial insects. When aphid populations on the legumes crash, beneficial insects seek alternative food sources in the pecan trees, thus reducing the necessity for pesticide applications. Preliminary studies suggest that a mixture of 'Dixie' crimson clover and hairy vetch produces high populations of beneficial insects and over 100 kg·ha-1 N. Treatments were established at four pecan orchard sites in Oklahoma, each with 5 ha of a crimson clover/vetch mixture and 5 ha of native grass sod. Additions of 0-200 kg·ha-1 N were added to the sod plots but no supplemental N was added to the legume plots. Nitrogen and biomass production by the legumes, and leaf N concentration of pecans were determined. In addition, both aphid and beneficial insect populations were monitored in the legume and grass treatments, and in the pecan trees. Results will be discussed in the presentation.
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KUMAR, J., A. PRATAP, R. K. SOLANKI, D. S. GUPTA, A. GOYAL, S. K. CHATURVEDI, N. NADARAJAN y S. KUMAR. "Genomic resources for improving food legume crops". Journal of Agricultural Science 150, n.º 3 (30 de junio de 2011): 289–318. http://dx.doi.org/10.1017/s0021859611000554.
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SUMMARYFood legumes are the main source of dietary protein for a large part of the world's population, and also play an important role in maintaining soil fertility through nitrogen fixation. However, legume yields and production are often limited by large genotype×environment (G×E) interactions that influence the expression of agronomically important, complex quantitative traits. Consequently, genetic improvement has been slower than expected. Molecular marker technology enables genetic dissection of such complex traits, allowing breeders to identify genomic regions on the chromosome that have main effects or interactive effects. A number of genomic resources have been developed in several legume species during the last two decades, and provide a platform for exploiting marker technology. The present paper reviews the available genomic resources in food legumes: linkage maps, high-throughput sequencing technologies, expression sequence tag (EST) databases, genome sequences, DNA chips, targeting induced local lesions in genomes (TILLING), bacterial artificial chromosome (BAC) libraries and others. It also describes how these resources are being used to tag and map genes/quantitative trait loci (QTLs) for domesticated and other agronomically important traits. This information is important to genetic improvement efforts aiming at improving food and nutrition security worldwide.
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Connor, David J. "Land required for legumes restricts the contribution of organic agriculture to global food security". Outlook on Agriculture 47, n.º 4 (21 de octubre de 2018): 277–82. http://dx.doi.org/10.1177/0030727018805765.
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Commercial extraction of nitrogen (N) from the atmosphere began soon after World War II and has provided N fertilizer that has transformed agriculture to meet, through greater crop areas and yields although with some regional shortfalls, the increasing food demand of a world population that has increased from 2 billion then to 7.6 billion in 2018. N fertilizer now provides more N input to agriculture (113 Mt N/year) than biological N fixation by legumes (33–46 Mt N/year) on which earlier agriculture relied entirely. Persistent claims over the last decade for return to organic methods, which include rejection of fertilizer N, are based on studies that erroneously claim adequate productivity to feed the world. Previous analyses, by contrast, have estimated that organic agriculture (OA) could at best support a world population of three to four billion. The problem is two-fold. First, organic crops grown in sequences with legumes or treated with N manures mostly yield less than crops grown with N fertilizer. Second, substantial areas of legumes are required to provide adequate N for required yields of non-legume crops. Recent analyses have overestimated the yield of organic crops by omitting the effect of weeds, pests and diseases, and by ignoring the land required for legumes. The result is a large overestimation of the relative productivity of OA. The effect of area is critical because, since there is little opportunity to increase cropping area beyond the current 1400 Mha, land for legumes means less land for, and consequently lower total production from, non-legume food crops. To replace 100 Mt N fertilizer/year with legumes at a net fixation of 100 kg N/ha/year would leave just 30% of cropland available for non-legumes producing a similar proportion of current yield. Even with major gains in yield, organic systems cannot feed our populous world and less so as the population increases to an expected 9.8 billion by 2050.
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Barros, Felipe Martins do Rêgo, Giselle Gomes Monteiro Fracetto, Felipe José Cury Fracetto, José Petrônio Mendes Júnior, Victor Lucas Vieira Prudêncio de Araújo y Mario Andrade Lira Junior. "Silvopastoral systems drive the nitrogen-cycling bacterial community in soil". Ciência e Agrotecnologia 42, n.º 3 (junio de 2018): 281–90. http://dx.doi.org/10.1590/1413-70542018423031117.
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ABSTRACT Intercropping tree legumes with forage grasses in a silvopastoral system can avoid pasture degradation benefiting the soil. In such a system, nitrogen (N) is supplied by symbiosis between legumes and bacteria. However, the pasture quality determines the action of free-living nitrogen-fixing bacteria, which possess nifH genes, which encode nitrogenase enzyme. Ammonium-oxidizing bacteria (AOB), involved in the nitrification step, can be evaluated by specific regions of the 16S rRNA corresponding to AOB. Thus, we investigated the influence of the introduction of tree legumes into a silvopastoral system on the community structure and abundance of total bacteria, diazotrophic bacteria and ammonium-oxidizing bacteria by DGGE (denaturing gradient gel electrophoresis) and real-time qPCR (quantitative PCR). The experiment involved nine plots of one hectare each, planted with sabia (Mimosa caesalpinifolia), a Gliricidia species (Gliricidia sepium), and a Brachiaria species (Brachiaria decumbens) in a randomized block design, forming three treatments: I-Brachiaria intercropped with sabia; II-Brachiaria intercropped with Gliricidia and III-Brachiaria only, with three replicates. The structures of the total bacterial and ammonium-oxidizing bacterial communities were influenced by tree legume introduction, possibly through modification of the soil chemical attributes. The copy numbers of total bacteria, ammonium-oxidizing bacteria and diazotrophic bacteria were higher in soils planted with legumes, which provided better conditions for microbial growth compared to planting with the Brachiaria species alone. Silvopastoral management with tree legumes improves the biological quality of soil, favouring the bacterial community linked to N-cycling.
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Neugschwandtner, Reinhard W., Alexander Bernhuber, Stefan Kammlander, Helmut Wagentristl, Agnieszka Klimek-Kopyra, Tomáš Lošák, Kuanysh K. Zholamanov y Hans-Peter Kaul. "Nitrogen Yields and Biological Nitrogen Fixation of Winter Grain Legumes". Agronomy 11, n.º 4 (2 de abril de 2021): 681. http://dx.doi.org/10.3390/agronomy11040681.
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Grain legumes are valuable sources of protein and contribute to the diversification and sustainability of agricultural systems. Shifting the sowing date from spring to autumn is a strategy to address low yields of spring grain legumes under conditions of climate change. A two-year field experiment was conducted under Pannonian climate conditions in eastern Austria to assess the nitrogen yield and biological N2 fixation of winter peas and winter faba beans compared to their spring forms. The grain nitrogen yields of winter peas and winter faba beans were 1.83-fold and 1.35-fold higher compared to their spring forms, respectively, with a higher value for winter peas. This was mainly due to higher grain yields of winter legumes, as winter faba beans had a 1.06-fold higher grain nitrogen concentration than spring faba bean. Soil mineral nitrate after harvest was similar for all grain legumes, with by 2.85- and 2.92-fold higher values for peas and faba beans than for cereals, respectively. The N2 fixation of winter peas and winter faba beans were 3.90-fold and 2.28-fold higher compared to their spring forms, with winter peas having a 1.60-fold higher N2 fixation than winter faba beans. The negative nitrogen balance of winter peas was smaller than that of winter faba beans as they demonstrated the ability to overcompensate for higher nitrogen removal with grain through higher N2 fixation. The cultivation of winter grain legumes, especially winter peas, can be recommended under Pannonian climate conditions as they achieve high nitrogen yields and high levels of N2 fixation.
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Silva, Charlley de Freitas, Erika Valente de Medeiros, Marthony Dornelas Santana, Maysa Bezerra de Araújo, Argemiro Pereira Martins Filho y Mácio Farias de Moura. "SOIL MICROBIOLOGICAL ACTIVITY AND PRODUCTIVITY OF MAIZE FODDER WITH LEGUMES AND MANURE DOSES". Revista Caatinga 31, n.º 4 (diciembre de 2018): 882–90. http://dx.doi.org/10.1590/1983-21252018v31n410rc.
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ABSTRACT Maize is an important cereal and it is widely consumed in the world, both as food for humans and animals. Nitrogen (N) is a nutrient required in large quantities by maize, but unfortunately, soils are limited in meeting this need. Nodulating legumes can serve as a source of Nitrogen, because they are symbiotically associated with bacteria capable of fixing atmospheric N. Another important source of this nutrient is cattle manure, which is widely used in agriculture. The objective of the present study was to evaluate the effect of using legumes and cattle manure on the production as well as the microbial and biochemical quality of the soil used for maize cultivation. The experiment was conducted using a randomized complete block design, in a sub-subdivided plot scheme [(2x4) +2], two leguminous plants (pigeon pea and macassar bean), four doses of cattle manure (0, 20, 40 and 60 t ha-1) and two controls; one with mineral fertilization and the other cultivated without the use of fertilizers. Treatment using a manure dose of 60t ha-1 and pigeon pea legume, recorded higher dry mass production per plant. The increase in manure doses was directly proportional to the length and weight of the cobs for the two legumes. The enzymatic activities were affected by the different doses and legumes, with greater results being recorded at the 60 t ha-1 dose with the macassar legume. The use of legumes with manure improved maize production as well as the microbiological and biochemical quality of soils.
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Martin, Kirsty, Grant Edwards, Rachael Bryant, Miriam Hodge, Jim Moir, David Chapman y Keith Cameron. "Herbage dry-matter yield and nitrogen concentration of grass, legume and herb species grown at different nitrogen-fertiliser rates under irrigation". Animal Production Science 57, n.º 7 (2017): 1283. http://dx.doi.org/10.1071/an16455.
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An important goal in dairy systems is to increase production while achieving environmental targets associated with lower nitrate leaching from soils. One approach is to identify forages that grow more at a given level of nitrogen (N) input and result in a lower N intake per kilogram dry matter (DM) consumed. However, while N responses have been well described for perennial ryegrasses, less information is available for alternative grasses, legumes and herbs. In the present study, conducted on the Canterbury Plains, New Zealand, six species (perennial ryegrass, Italian ryegrass, white clover, lucerne, chicory and plantain) were grown at six N-fertiliser rates ranging from 0 to 450 kg N/ha.year and managed under irrigation and cutting management. Herbage DM yield and N concentration were measured over 12 months. As N-fertiliser rate increased from 0 to 450 kg N/ha, annual herbage yield increased linearly (from 4794 to 14 329 kg DM/ha.year in grasses and from 7146 to 13 177 kg DM/ha.year in herbs). In contrast, annual herbage yield for legumes was unaffected by N-fertiliser rate and ranged from 11 874 to 13 112 kg DM/ha. Additionally, there were contrasting responses in herbage N concentration between species. At all N-fertiliser rates, herbage N concentration was highest in legumes (43.4 g N/kg DM), then herbs (30.7 g N/kg DM), and lowest in grasses (25.8 g N/kg DM). The N concentration of legume DM was unaffected by increasing N-fertiliser rate, whereas in grasses and herbs it increased. Results suggested that there were no benefits in using herbs instead of grasses for reducing N intake in livestock in an irrigated Canterbury environment.
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Beck, D. P., J. Wery, M. C. Saxena y A. Ayadi. "Dinitrogen Fixation and Nitrogen Balance in Cool‐Season Food Legumes". Agronomy Journal 83, n.º 2 (enero de 1991): 334–41. http://dx.doi.org/10.2134/agronj1991.00021962008300020015x.
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STODDARD, F. L., S. HOVINEN y M. KONTTURI. "Legumes in Finnish agriculture: history, present status and future prospects". Agricultural and Food Science 18, n.º 3-4 (4 de diciembre de 2008): 191. http://dx.doi.org/10.2137/145960609790059578.
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Legumes are important in world agriculture, providing biologically fixed nitrogen, breaking cereal disease cycles and contributing locally grown food and feed, including forage. Pea and faba bean were grown by early farmers in Finland, with remains dated to 500 BC. Landraces of pea and faba bean were gradually replaced by better adapted, higher quality materials for food use. While grain legumes have been restricted by their long growing seasons to the south of the country, red, white and alsike clovers are native throughout and have long been used in leys for grazing, hay and silage. Breeding programmes released many cultivars of these crops during the 1900s, particularly pea and red clover. A.I. Virtanen earned the 1945 Nobel Prize in Chemistry for his work on both nitrogen fixation and silage preservation. Use of crop mixtures may appear modern, but farmers used them already in the early 1800s, when oat was used to support pea, and much effort has been devoted to improving the system and establishing its other benefits. Although international cultivars have been easily accessible since Finlands 1995 entry into the European Union, the combination of feed quality and appropriate earliness is still needed, as < 1% of arable land is sown to grain legumes and an increase to 910% would allow replacement of imported protein feeds. Climate change will alter the stresses on legume crops, and investment in agronomy, physiology and breeding is needed so that farmers can gain from the many advantages of a legume-supported rotation.;
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Mytton, L. R. "European perspectives on nitrogen fixation and the application of mineral nitrogen". NZGA: Research and Practice Series 6 (1 de enero de 1996): 95–98. http://dx.doi.org/10.33584/rps.6.1995.3345.
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An analysis is made of the main factors influencing nitrogen use in the European Union (EU). The Common Agricultural Policy (CAP) is identified as a major factor. A brief explanation is given of its functions and of recent reforms which are aimed at reducing overproduction. These reforms should favour more efficient use of nitrogen. The reasons why this is difficult to achieve are explained and the major factors influencing our ability to balance the nitrogen economies of food production are identified. The interrelationship between these factors is then used to predict the impact of CAP reforms on research, on fertiliser use and on the wider use of legumes. Keywords: Common Agricultural Policy, Europe, farm subsidies, legumes, nitrogen cycle, nitrogen fertiliser, nitrogen fixation, over-production, pollution, soil organic matter
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Smýkal, Petr, Eric J. B. von Wettberg y Kevin McPhee. "Legume Genetics and Biology: From Mendel’s Pea to Legume Genomics". International Journal of Molecular Sciences 21, n.º 9 (8 de mayo de 2020): 3336. http://dx.doi.org/10.3390/ijms21093336.
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Legumes have played an important part in cropping systems since the dawn of agriculture, both as human food and as animal feed. The legume family is arguably one of the most abundantly domesticated crop plant families. Their ability to symbiotically fix nitrogen and improve soil fertility has been rewarded since antiquity and makes them a key protein source. The pea was the original model organism used in Mendel’s discovery of the laws of inheritance, making it the foundation of modern plant genetics. This Special Issue provides up-to-date information on legume biology, genetic advances, and the legacy of Mendel.
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Mhango, Wezi G., Sieglinde S. Snapp y George Y. K. Phiri. "Opportunities and constraints to legume diversification for sustainable maize production on smallholder farms in Malawi". Renewable Agriculture and Food Systems 28, n.º 3 (16 de mayo de 2012): 234–44. http://dx.doi.org/10.1017/s1742170512000178.
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AbstractSustainable intensification of smallholder farms in Africa is highly dependent on enhancing biological nitrogen fixation (BNF). Legume diversification of maize-based systems is a core example of sustainable intensification, with the food security of millions of farm families at stake. This study highlights the constraints and opportunities associated with the adoption of legumes by smallholder farmers in southern Africa. A two-part survey of households and farm fields (n=88) was conducted in the Ekwendeni watershed of northern Malawi. Participatory research and education activities have been underway for over a decade in this region, resulting in expanded uptake of a range of legume species as intercrops and in rotation with the staple maize crop. Farmer adoption has occurred to a varying extent for soybean (Glycine max), pigeon pea (Cajanus cajan), velvet bean (Mucuna pruriens) and fish bean (Tephrosia vogelii). Farmers, working with the project valued pigeon pea and other legumes for soil fertility purposes to a greater extent than farmers not working with the project. Legumes were valued for a wide range of purposes beyond soil cover and fertility enhancement, notably for infant nutrition (at least for soybean), insect control, and vegetable and grain production for both market and home consumption. Literature values for BNF in tropical legumes range up to 170 kg N ha−1for grain and 300 kg N ha−1for green manure species; however, our field interviews illustrated the extent of constraints imposed by soil properties on smallholder fields in Malawi. The key edaphic constraints observed were very deficient to moderate phosphorus levels (range 4–142, average 33 mg kg−1), and moderately acid soils (range pH 5.1–7.9, average 6.2). The per farm hectarage devoted to legume production relative to maize production was also low (0.15 versus 0.35 ha), a surprising find in an area with demonstrated interest in novel legume species. Further, farmers showed a strong preference for legumes that produced edible grain, regardless of the associated nutrient removal in the harvested grain, and did not sow large areas to legume crops. These farm-level decisions act as constraints to BNF inputs in maize-based smallholder cropping systems. Overall, we found that legume productivity could be enhanced. We documented the value of policies and educational efforts that support farmers gaining access to high-quality seeds, amendments for phosphorus-deficient soils, and promotion of multipurpose legumes that build soils through leafy residues and roots, as well as providing grain for food security and sales.
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Materon, L. A., J. D. H. Keatinge, D. P. Beck, N. Yurtsever, K. Karuc y S. Altuntas. "The Role of Rhizobial Biodiversity in Legume Crop Productivity in the West Asian Highlands". Experimental Agriculture 31, n.º 4 (octubre de 1995): 485–91. http://dx.doi.org/10.1017/s0014479700026466.
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SUMMARYThe native rhizobia capable of symbiosis with annually-sown food and forage legume crops in the Turkish highlands were surveyed and estimates made of the numbers and nitrogen fixing efficiency of native Rhizobium leguminosarum with Turkish cultivars of lentil (Lens culinaris Medik.) and vetch (Vicia sativa L.). Native rhizobia were present in medium to high numbers in most samples but the nitrogen fixation efficiency of at least half of the isolates was poor. Vetch was somewhat less specific in its rhizobial compatibility than lentil, suggesting a potential for artificial inoculation to improve the productivity and sustainability of cropping in both species especially in areas of central and eastern Anatolia where legumes are not traditionally grown.Biodiversidad en el Rhizobium leguminosarum
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Castro-Montoya, J. M., K. Goetz y U. Dickhoefer. "In vitro fermentation characteristics of tropical legumes and grasses of good and poor nutritional quality and the degradability of their neutral detergent fibre". Animal Production Science 61, n.º 7 (2021): 645. http://dx.doi.org/10.1071/an20136.
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Context Tropical legumes are commonly assumed to share all positive attributes known from temperate legumes such as lucerne. However, increasing evidence exists on the differences between those forages, particularly in terms of their ruminal degradability. Aims Exploring the 24-h rumen in vitro-fermentation characteristics of tropical legumes, their direct comparison with lucerne, and their interactions with grasses depending on their nutritional quality. Methods Arachis and stylosanthes (tropical legumes), pennisetum and andropogon (tropical grasses), and lucerne (lucerne_21 and lucerne_35, harvested 21 and 35 days after emergence respectively) were used for the study. On the basis of the nitrogen and neutral detergent fibre (NDF) concentration, arachis and pennisetum were classified as of good quality, while stylosanthes and andropogon as of poor quality. The following four incubation series were performed: first, forages alone were incubated under iso-nitrogenous conditions; second, forages were incubated under iso-nitrogenous conditions with supplemented starch; third, NDF extract of each forage was incubated alone; fourth, NDF extract of tropical grasses and legumes was incubated combined in grass:legume proportions of 33:67 and 67:33. Key results When incubated alone, gas production (GP) and total short chain fatty acids were higher for temperate legumes, intermediate for tropical legumes and lowest for tropical grasses. Similar trends were observed for GP when the forages were incubated with starch, but the differences between arachis and lucerne_35 disappeared; short chain fatty acids did not differ among all tropical forages. Moreover, acetate:propionate ratio was highest for tropical legumes, intermediate for temperate legumes, and lowest for tropical grasses. Gas production of NDF extracts was highest for the lucerne samples and lowest for the tropical legumes. Improvements in GP were found when the NDF from the poor-quality grass (andropogon) was combined with the legumes, particularly the good-quality legume (arachis). Conclusions On the basis of the gas production, tropical legumes appear to have lower degradability than do temperate ones, while also showing a different fermentation pattern. Fibre of tropical legumes is less degradable than that of tropical grasses, but when combining both fibre sources, there seems to be a synergistic effect on degradability. Implications The current results give important insights on the fermentation characteristics of tropical legumes, helping better understand their role in ruminants’ nutrition, while giving inputs towards improving their utilisation.
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Herridge, D. F., O. P. Rupela, R. Serraj y D. P. Beck. "Screening techniques and improved biological nitrogen fixation in cool season food legumes". Euphytica 73, n.º 1-2 (1994): 95–108. http://dx.doi.org/10.1007/bf00027186.
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Villegas, Daniel M., Jaime Velasquez, Jacobo Arango, Karen Obregon, Idupulapati M. Rao, Gelber Rosas y Astrid Oberson. "Urochloa Grasses Swap Nitrogen Source When Grown in Association with Legumes in Tropical Pastures". Diversity 12, n.º 11 (5 de noviembre de 2020): 419. http://dx.doi.org/10.3390/d12110419.
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The degradation of tropical pastures sown with introduced grasses (e.g., Urochloa spp.) has dramatic environmental and economic consequences in Latin America. Nitrogen (N) limitation to plant growth contributes to pasture degradation. The introduction of legumes in association with grasses has been proposed as a strategy to improve N supply via symbiotic N2 fixation, but the fixed N input and N benefits for associated grasses have hardly been determined in farmers’ pastures. We have carried out on-farm research in ten paired plots of grass-alone (GA) vs. grass-legume (GL) pastures. Measurements included soil properties, pasture productivity, and sources of plant N uptake using 15N isotope natural abundance methods. The integration of legumes increased pasture biomass production by about 74%, while N uptake was improved by two-fold. The legumes derived about 80% of their N via symbiotic N2 fixation. The isotopic signature of N of grasses in GA vs. GL pastures suggested that sources of grass N are affected by sward composition. Low values of δ15N found in some grasses in GA pastures indicate that they depend, to some extent, on N from non-symbiotic N2 fixation, while δ15N signatures of grasses in GL pastures pointed to N transfer to grass from the associated legume. The role of different soil–plant processes such as biological nitrification inhibition (BNI), non-symbiotic N2 fixation by GA pastures and legume–N transfer to grasses in GL pastures need to be further studied to provide a more comprehensive understanding of N sources supporting the growth of grasses in tropical pastures.
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Lemaire, Benny, Samson B. M. Chimphango, Charles Stirton, Suhail Rafudeen, Olivier Honnay, Erik Smets, Wen-Ming Chen, Janet Sprent, Euan K. James y A. Muthama Muasya. "Biogeographical Patterns of Legume-Nodulating Burkholderia spp.: from African Fynbos to Continental Scales". Applied and Environmental Microbiology 82, n.º 17 (17 de junio de 2016): 5099–115. http://dx.doi.org/10.1128/aem.00591-16.
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ABSTRACTRhizobia of the genusBurkholderiahave large-scale distribution ranges and are usually associated with South African papilionoid and South American mimosoid legumes, yet little is known about their genetic structuring at either local or global geographic scales. To understand variation at different spatial scales, from individual legumes in the fynbos (South Africa) to a global context, we analyzed chromosomal (16S rRNA,recA) and symbiosis (nifH,nodA,nodC) gene sequences. We showed that the global diversity of nodulation genes is generally grouped according to the South African papilionoid or South American mimosoid subfamilies, whereas chromosomal sequence data were unrelated to biogeography. While nodulation genes are structured on a continental scale, a geographic or host-specific distribution pattern was not detected in the fynbos region. In host range experiments, symbiotic promiscuity ofBurkholderiatuberumSTM678TandB.phymatumSTM815Twas discovered in selected fynbos species. Finally, a greenhouse experiment was undertaken to assess the ability of mimosoid (Mimosapudica) and papilionoid (Dipogonlignosus,Indigoferafilifolia,Macroptiliumatropurpureum, andPodalyriacalyptrata) species to nodulate in South African (fynbos) and Malawian (savanna) soils. While theBurkholderia-philous fynbos legumes (D.lignosus,I.filifolia, andP.calyptrata) nodulated only in their native soils, the invasive neotropical speciesM.pudicadid not develop nodules in the African soils. The fynbos soil, notably rich inBurkholderia, seems to retain nodulation genes compatible with the local papilionoid legume flora but is incapable of nodulating mimosoid legumes that have their center of diversity in South America.IMPORTANCEThis study is the most comprehensive phylogenetic assessment of root-nodulatingBurkholderiaand investigated biogeographic and host-related patterns of the legume-rhizobial symbiosis in the South African fynbos biome, as well as at global scales, including native species from the South American Caatinga and Cerrado biomes. While a global investigation of the rhizobial diversity revealed distinct nodulation and nitrogen fixation genes among South African and South American legumes, regionally distributed species in the Cape region were unrelated to geographic and host factors.
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Bell, RW, DG Edwards y CJ Asher. "Effects of calcium supply on uptake of calcium and selected mineral nutrients by tropical food legumes in solution culture". Australian Journal of Agricultural Research 40, n.º 5 (1989): 1003. http://dx.doi.org/10.1071/ar9891003.
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Six tropical food legumes, peanut (Arachis hypogaea (L.) cv. Red Spanish), pigeonpea (Cajanus cajan (L.) Millsp. cv. Royes), guar (Cyarnopsis tetragonoloba (L.) Taub. cv. Brooks), soybean (Glycine max (L.) Merr. cv. Fitzroy), and cowpea (Vigna unguiculuta (L.) Walp. cv. Vita 4 and CPI 282 15) were grown for 20 days at six constant solution calcium concentrations (2, 12, 50, 100,500 and 2500 8M ) in flowing solution culture at pH 5.5 � 0.1, with adequate inorganic nitrogen and controlled basal nutrient concentrations. Increases in solution calcium concentration from 2 to 12 8M generally increased rates of absorption of nitrogen, phosphorus, potassium, manganese and zinc, and rates of transport of magnesium and iron to plant tops. These increases in nutrient absorption and transport rates were associated with the alleviation of severe calcium deficiency. Further increases in solution calcium concentration from 12 to 2500 8M generally had no effect on potassium absorption rate, but increased absorption rates of nitrogen (by 20-130%), and phosphorus (by 90-500%), and decreased those of manganese and zinc; it also decreased rates of transport of iron and magnesium to plant tops. With guar, rates of phosphorus absorption at <2500 8M calcium were too low to maintain adequate concentrations of phosphorus in tops for maximum growth. With the remaining legumes, rates of zinc absorption at 12 8M calcium were high enough for plants to accumulate excessive concentrations of zinc (347-479 mg kg-1) in their tops. These results are discussed in relation to the adaptation of tropical food legumes to soils with low concentrations of calcium in the soil solution and the response of legumes to calcium or lime applications.
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Lagrange, Sebastian, Karen Beauchemin, Jennifer MacAdam y Juan J. Villalba. "94 President Oral Presentation Pick: Grazing diverse combinations of tanniferous and non-tanniferous legumes: Implications for beef cattle performance and environmental impact". Journal of Animal Science 98, Supplement_4 (3 de noviembre de 2020): 76–77. http://dx.doi.org/10.1093/jas/skaa278.139.
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Abstract We tested the effect of increasingly diverse combinations of tanniferous legumes (birdsfoot trefoil-BFT, sainfoin-SF) and alfalfa (ALF) on cattle performance, methane (CH4) emissions and nitrogen (N) balance. Pairs of heifers (401 ± 49.6 kg) grazed three spatial replications of 7 treatments (n = 3/treatment): monocultures (BFT, SF, ALF) and all possible 2- and 3-way choices among strips of these legumes in a completely randomized block design of two 15-d periods during 2 consecutive years. Average daily gains (ADG) of heifers grazing the tanniferous legumes (1.05 kg/d) were 40% greater (P < 0.10) than of heifers grazing ALF (0.74 kg/d) during the first year. Heifers grazing the 3-way choice had greater intakes (10.4 vs 7.8 kg/d; P = 0.064) and ADG (1.21 vs. 0.95 kg/d, P = 0.054) than those grazing monocultures, suggesting a nutritional synergism among legumes. The average CH4 emissions for legume monocultures vs. 2- and 3-way choices was 222 vs. 202 and 162 g/kg BW gain (P > 0.10), respectively. For heifers grazing SF and BFT compared with ALF, blood urea N was less (14.3 and 16.8 vs 20.8 mg/dL; P < 0.05) as were urinary N concentrations (3.7 and 3.5 vs 6.0 g/L; P < 0.05), but fecal N concentrations were greater (34.5 and 35.5 vs 30.5 g/kg, respectively; P < 0.05). Combining both tanniferous legumes (SF-BFT) led to the greatest declines in urinary N (2.24 g/L) and urea-N (1.71 g/L) concentration, suggesting that different types of tannins in different legume species result in associative effects that enhance N economy. In addition, heifers grazing 3-way choices partitioned less N into urine (40.7 vs 50.6%; P = 0.037) and retained more N (36.1 vs 25.2%, P = 0.046) than heifers grazing monocultures. In summary, combinations of tanniferous legumes with alfalfa improved animal performance and reduced environmental impacts relative to monocultures, resulting in a more sustainable approach to beef production in pasture-based finishing systems.
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Koropeckyj-Cox, Lydia, Reid D. Christianson y Yongping Yuan. "Effectiveness of Conservation Crop Rotation for Water Pollutant Reduction from Agricultural Areas". Transactions of the ASABE 64, n.º 2 (2021): 691–704. http://dx.doi.org/10.13031/trans.14017.
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HighlightsAdjusting nitrogen (N) fertilization rates for corn following legumes can reduce N losses.Including perennial legumes in corn rotations can reduce nitrate-N losses and improve water quality.Crop rotations that include three or more years of legumes can be cost-effective.Corn-soybean was the most cost-effective, with a net benefit in nitrate-N loss reduction compared to continuous corn.Abstract. Legumes included in corn-based crop rotation systems provide a variety of benefits to the subsequent crops and potentially to the environment. This review aims to synthesize available data from the literature on legume N credits and the effects of crop rotations on water quality, as well as to analyze the cost benefits associated with different legume-corn rotation systems. We found that there was much variation in reported values for legume N credits to subsequent corn crops, from both empirical results and recommendations made by U.S. land grant universities. But despite inherent complexity, accounting for this contribution is critical when estimating optimal N fertilizer application rates as part of nutrient management. Results from research on the influence of crop rotations on water quality show that including legumes in corn-based rotation systems generally decreases nitrate-N concentrations in subsurface drainage discharge. Our cost analysis showed that incorporating legumes in cropping systems reduced N fertilizer and pesticide costs compared to conventional cropping systems, i.e., continuous corn and corn-soybean rotations, but extended rotations, such as corn-soybean-alfalfa-alfalfa-alfalfa, are not as profitable as conventional systems in the U.S. Midwest. In comparing continuous corn and corn-soybean rotations, although their impacts on water quality are not significantly different when using overall means from the literature data, corn-soybean rotations are more profitable than continuous corn. When using data from papers that directly compared the two, we found that switching from continuous corn to corn-soybean can provide a benefit of $5 per kg N loss reduction. The cost analysis methods used could be tailored to any location or management scenario with appropriate inputs and serve as a useful tool for assessing cost benefits for other agricultural conservation practices. Legume-corn crop rotations have the potential to be an effective conservation practice with the ultimate goal of improving water quality, and, with further research, these rotations could be made even more effective by integrating them into a multi-practice system. Keywords: Conservation practice, Cost analysis, Crop rotation, Nitrate, Nutrient management, Water quality.
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Herendeen, Patrick S. y William L. Crepet. "Paleobotanical and biogeographic history of the legumes (Leguminosae), an important component in Cenozoic and modern tropical terrestrial ecosystems". Paleontological Society Special Publications 6 (1992): 127. http://dx.doi.org/10.1017/s2475262200006870.
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The Leguminosae are consistently one of the two or three most important angiosperm families in diversity and abundance in modern African and American tropical and subtropical lowland ecosystems. Many legumes are colonizers of disturbed sites while others are components of more mature communities. The great diversity and abundance of legumes reflects characteristics that have made them important components of tropical ecosystems. One of the most significant of these is the ability of most legume species to enrich the soil through the activities of bacteria in their root nodules. Legumes are also important as sources of food to vertebrate and invertebrate pollinators alike. Legumes have well known plant-pollinator relationships with bats, birds, hymenoptera, and lepidoptera and their diversity is sometimes linked with their strong association with specialized animal pollinators. Legumes also enjoy a variety of unusual defense strategies based on various interrelationships with ants. Thus, the evolution of specialized interrelationships with a diversity of organisms has helped the legumes become a family of considerable importance in American and African tropical ecosystems.Legumes are well represented in the fossil record and the paleobotanical data now available demonstrate that the family was an important component in tropical ecosystems by the Paleocene/Eocene. Sediments of the Mississippi Embayment in southeastern North America are yielding the most abundant and diverse assemblage of fossil legumes. The individual legume taxa in this specific subtropical to tropical flora represent a wide variety of different biogeographic distribution patterns. Legume fossils that are most closely related to extant taxa that occur only in tropical South America today are the most common components of this assemblage. Other biogeographic distribution patterns include American-Asian disjuncts, Asian, African, and Pantropical taxa. Although several of the fossil taxa are widespread in the North American Tertiary, these cases are restricted to taxa that have an Old World Tropics or American-Asian disjunct distribution today. The South American taxa seem to have been largely restricted to the Mississippi Embayment system.The Paleocene/Eocene legume fossil flora suggests that nitrogen fixation and highly specific insect pollination mechanisms were well established by that time. In addition, bat pollination in legumes may have been established by the upper Eocene. Specialized foliar glands, which are indicative of defense strategies involving ants, are present by at least the Oligocene. Although fruit and seed dispersal in legumes is largely abiotic, a wide variety of fruiting structures and abiotic dispersal mechanisms occur in the family and many of these were present by the Eocene.This study of the fossil record of the Leguminosae is demonstrating that the legumes were well established and diverse by the Paleocene/Eocene and that many of the functions and relationships that make them important in modern tropical ecosystems were established by that time.
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AbdElgawad, Hamada, Walid Abuelsoud, Mahmoud M. Y. Madany, Samy Selim, Gaurav Zinta, Ahmed S. M. Mousa y Wael N. Hozzein. "Actinomycetes Enrich Soil Rhizosphere and Improve Seed Quality as well as Productivity of Legumes by Boosting Nitrogen Availability and Metabolism". Biomolecules 10, n.º 12 (15 de diciembre de 2020): 1675. http://dx.doi.org/10.3390/biom10121675.
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The use of actinomycetes for improving soil fertility and plant production is an attractive strategy for developing sustainable agricultural systems due to their effectiveness, eco-friendliness, and low production cost. Out of 17 species isolated from the soil rhizosphere of legume crops, 4 bioactive isolates were selected and their impact on 5 legumes: soybean, kidney bean, chickpea, lentil, and pea were evaluated. According to the morphological and molecular identification, these isolates belong to the genus Streptomyces. Here, we showed that these isolates increased soil nutrients and organic matter content and improved soil microbial populations. At the plant level, soil enrichment with actinomycetes increased photosynthetic reactions and eventually increased legume yield. Actinomycetes also increased nitrogen availability in soil and legume tissue and seeds, which induced the activity of key nitrogen metabolizing enzymes, e.g., glutamine synthetase, glutamate synthase, and nitrate reductase. In addition to increased nitrogen-containing amino acids levels, we also report high sugar, organic acids, and fatty acids as well as antioxidant phenolics, mineral, and vitamins levels in actinomycete treated legume seeds, which in turn improved their seed quality. Overall, this study shed the light on the impact of actinomycetes on enhancing the quality and productivity of legume crops by boosting the bioactive primary and secondary metabolites. Moreover, our findings emphasize the positive role of actinomycetes in improving the soil by enriching its microbial population. Therefore, our data reinforce the usage of actinomycetes as biofertilizers to provide sustainable food production and achieve biosafety.
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Salgado, Gabriela Cristina, Edmilson Jose Ambrosano, Fabrício Rossi, Ivani Pozar Otsuk, Gláucia Maria Bovi Ambrosano, Cesar Augusto Santana, Takashi Muraoka y Paulo Cesar Ocheuze Trivelin. "Biological N Fixation and N Transfer in an Intercropping System between Legumes and Organic Cherry Tomatoes in Succession to Green Corn". Agriculture 11, n.º 8 (22 de julio de 2021): 690. http://dx.doi.org/10.3390/agriculture11080690.
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The aim of this study was to investigate the transfer of N from different legumes to cherry tomatoes in the intercropping system under residual straw of the previous green corn crop using the 15N natural abundance method. We also investigated the temporal variation in nitrogen transfer to a cherry tomato, the biological nitrogen fixation (BNF) of legumes, and the N concentration of green corn cultivated in the intercrop succession. The experimental design was a complete randomized block with eight treatments and five replications, described as follows: two controls consisting of a monocrop of cherry tomato with or without residual straw, cherry tomato and jack bean, sun hemp, dwarf velvet bean, mung bean, and white lupine or cowpea bean in intercropping system. The BNF was responsible for more than half of the N accumulated in the legumes. The N of legumes was transferred to cherry tomato in similar quantities, and the leaves and fruits of cherry tomato received more N transfer than shoots. It was shown that N transfer increases with the growth/development of cherry tomatoes. The intercropping system with legumes did not affect the 15N natural abundance of leaves and the aboveground biomass of green corn cultivated in succession.
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Fariani, A., L. Warly, T. Ichinohe y T. Fujihara. "In vitro rumen degradation of legumes in south Sumatra, Indonesia". BSAP Occasional Publication 22 (1998): 241–43. http://dx.doi.org/10.1017/s0263967x00032730.
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Legumes have a significant role in many farming systems of the tropics and subtropics through their contribution to enhanced nutritive value of the animal diet, biological nitrogen fixation and landscape stability (Humphreys, 1995). The great potential of legumes to increase productivity of livestock is being related with their high content of nutrients, especially protein and other nutrients often deficient in grass or low quality hay diets for ruminants. In Indonesia, legumes are often used for replacement of costly concentrate in ruminants diets. Norton and Poppi (1995) reported that quality of tropical legumes varies between and within species but is generally higher than that of tropical grasses. It is well known that the major factors limiting intake and digestibility are those associated with rate and extent of forage degradation by microbial and physical factors in the rumen, primarily the amount of cell wall constituents and the extent of lignification. Association of polysaccharides of cell wall with lignin hinders attack by microbial enzymes and prevents the physical attachment of bacteria to the cell wall. Menke et al. (1979) reported that the amount of gas released when a food is incubated in vitro in the rumen fluid, is also closely related to digestibility of the food and could be used to predict food intake. There is very little information available on the rumen degradation characteristics and in vitro gas production of the tropical legumes. Objectives of the present study were to assess differences in in vitro degradation and gas production between five commonly used legumes in south Sumatra, Indonesia.
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Bautista-Expósito, Sara, Elena Peñas, Albert Vanderberg, Juana Frias y Cristina Martínez-Villaluenga. "Effect of Time and Legume Type on Germination-Induced Proteolysis of Lentils and Faba Beans". Proceedings 70, n.º 1 (10 de noviembre de 2020): 4. http://dx.doi.org/10.3390/foods_2020-07823.
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Legumes are alternative protein sources that have been successfully used to develop diverse meatless foods. Although these plant-based products have a lower impact on the environment than equivalent animal-based products, they have lower protein digestibility. Germination could be a useful bioprocess to enhance protein digestibility in legumes, although its effect at different times of seedling development has been little studied in lentils and faba beans. This work investigated the effect of germination time (4 and 6 days after full seed imbibition) on the proteins of three types of Canadian lentils (“gray zero tannin”, G; “caviar black”, B; and “red dehulled”, D) and faba beans (“zero vicin/convicin”, F). Germination increased total nitrogen (4–14% increase) and total levels of some amino acids: Asp in all the sprouts studied; Ser, Pro, Ala, Cys, His and Lys in G; and Met and Tyr in B. A concurrent degradation of the 7S and 11S globulin subunits, the accumulation of peptides below 20 kDa and free essential and non-essential amino acids (4- to 6-fold increase) were observed after germination in all the legumes studied. These effects were attributable to the increased protease activity observed after sprouting. Trypsin inhibitory activity was lower in legume sprouts, except for D, where a small increase was detected. Time, legume type and their interaction showed significant effects on the parameters studied. Germination effects were generally more remarkable at longer stages of seedling development. Among the legumes studied, D showed a differential behavior characterized by a faster protein degradation and release of small peptides, probably due to its higher protease activity as indicated by principal component analysis. These results evidence the positive effects of germination on the protein digestibility of different lentil types and faba beans. The protein quality of plant-based foods could be improved through the selection of legume species with higher germination-induced proteolytic rates and optimized germination times.
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KIHARA, J., B. VANLAUWE, B. WASWA, J. M. KIMETU, J. CHIANU y A. BATIONO. "STRATEGIC PHOSPHORUS APPLICATION IN LEGUME-CEREAL ROTATIONS INCREASES LAND PRODUCTIVITY AND PROFITABILITY IN WESTERN KENYA". Experimental Agriculture 46, n.º 1 (30 de noviembre de 2009): 35–52. http://dx.doi.org/10.1017/s0014479709990810.
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SUMMARYMany food production systems in sub-Saharan Africa are constrained by phosphorus (P). We hypothesized that within legume-cereal rotation systems: targeting P to the legume phase leads to higher system productivity, and that use of grain legumes leads to better economic returns than use of herbaceous legumes. Four P application regimes: (i) no P, (ii) P applied every season, (iii) P applied in season 1 only and (iv) P applied in season 2 only were tested for four seasons in three cropping systems (continuous maize, mucuna-maize rotation and soybean-maize rotation) in a split plot experiment set up in Nyabeda, western Kenya. Treatments where P was applied were better than no P treatments. While continuous cereal systems showed the need for application of P every second season, rotation systems involving mucuna and soyabean indicated that application in one out of three seasons could be sufficient. Nitrogen fertilizer equivalence was 52 to >90 kg N ha−1for soyabean and 37 to >90 kg N ha−1for mucuna, depending on P fertilization and season. Analysis of marginal rates of return (MRR) showed that soybean-maize rotation with one application of P was the most economically viable option, with an MRR of at least 147% compared to other non-dominated options.
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Lagrange, Sebastian y Juan J. Villalba. "Tannin-containing legumes and forage diversity influence foraging behavior, diet digestibility, and nitrogen excretion by lambs1,2". Journal of Animal Science 97, n.º 9 (septiembre de 2019): 3994–4009. http://dx.doi.org/10.1093/jas/skz246.
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Abstract Diverse combinations of forages with different nutrient profiles and plant secondary compounds may improve intake and nutrient utilization by ruminants. We tested the influence of diverse dietary combinations of tannin- (sainfoin-Onobrichis viciifolia; birdsfoot trefoil-Lotus corniculatus) and non-tannin- (alfalfa-Medicago sativa L.) containing legumes on intake and diet digestibility in lambs. Freshly cut birdsfoot trefoil, alfalfa, and sainfoin were offered in ad libitum amounts to 42 lambs in individual pens assigned to 7 treatments (6 animals/treatment): 1) single forage species (sainfoin [SF], birdsfoot trefoil [BFT], and alfalfa [ALF]), 2) all possible 2-way choices of the 3 forage species (alfalfa-sainfoin [ALF-SF], alfalfa-birdsfoot trefoil [ALF-BFT], and sainfoin-birdsfoot trefoil [SF-BFT]), or 3) a choice of all 3 forages (alfalfa-sainfoin-birdsfoot trefoil [ALF-SF-BFT]). Dry matter intake (DMI) was greater in ALF than in BFT (P = 0.002), and DMI in SF tended to be greater than in BFT (P = 0.053). However, when alfalfa was offered in a choice with either of the tannin-containing legumes (ALF-SF; ALF-BFT), DMI did not differ from ALF, whereas DMI in SF-BFT did not differ from SF (P > 0.10). When lambs were allowed to choose between 2 or 3 legume species, DMI was greater (36.6 vs. 33.2 g/kg BW; P = 0.038) or tended to be greater (37.4 vs. 33.2 g/kg BW; P = 0.067) than when lambs were fed single species, respectively. Intake did not differ between 2- or 3-way choice treatments (P = 0.723). Lambs preferred alfalfa over the tannin-containing legumes in a 70:30 ratio for 2-way choices, and alfalfa > sainfoin > birdsfoot trefoil in a 53:33:14 ratio for the 3-way choice. In vivo digestibility (DMD) was SF > BFT (72.0% vs. 67.7%; P = 0.012) and DMD in BFT tended to be greater than in ALF (64.6%; P = 0.061). Nevertheless, when alfalfa was offered in a choice with either sainfoin or birdsfoot trefoil (ALF-SF; ALF-BFT), DMD was greater than ALF (P < 0.001 and P = 0.007, respectively), suggesting positive associative effects. The SF treatment had lower blood urea nitrogen and greater fecal N/N intake ratios than the ALF, BFT, or ALF-BFT treatments (P < 0.05), implying a shift in the site of N excretion from urine to feces. In conclusion, offering diverse combinations of legumes to sheep enhanced intake and diet digestibility relative to feeding single species, while allowing for the incorporation of beneficial bioactive compounds like condensed tannins into the diet.
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Rivas, Raul, Encarna Velázquez, Anne Willems, Nieves Vizcaíno, Nanjappa S. Subba-Rao, Pedro F. Mateos, Monique Gillis, Frank B. Dazzo y Eustoquio Martínez-Molina. "A New Species of Devosia That Forms a Unique Nitrogen-Fixing Root-Nodule Symbiosis with the Aquatic Legume Neptunia natans (L.f.) Druce". Applied and Environmental Microbiology 68, n.º 11 (noviembre de 2002): 5217–22. http://dx.doi.org/10.1128/aem.68.11.5217-5222.2002.
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ABSTRACT Rhizobia are the common bacterial symbionts that form nitrogen-fixing root nodules in legumes. However, recently other bacteria have been shown to nodulate and fix nitrogen symbiotically with these plants. Neptunia natans is an aquatic legume indigenous to tropical and subtropical regions and in African soils is nodulated by Allorhizobium undicola. This legume develops an unusual root-nodule symbiosis on floating stems in aquatic environments through a unique infection process. Here, we analyzed the low-molecular-weight RNA and 16S ribosomal DNA (rDNA) sequence of the same fast-growing isolates from India that were previously used to define the developmental morphology of the unique infection process in this symbiosis with N. natans and found that they are phylogenetically located in the genus Devosia, not Allorhizobium or Rhizobium. The 16S rDNA sequences of these two Neptunia-nodulating Devosia strains differ from the only species currently described in that genus, Devosia riboflavina. From the same isolated colonies, we also located their nodD and nifH genes involved in nodulation and nitrogen fixation on a plasmid of approximately 170 kb. Sequence analysis showed that their nodD and nifH genes are most closely related to nodD and nifH of Rhizobium tropici, suggesting that this newly described Neptunia-nodulating Devosia species may have acquired these symbiotic genes by horizontal transfer.
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Arnold, Markus F. F., Jon Penterman, Mohammed Shabab, Esther J. Chen y Graham C. Walker. "Important Late-Stage Symbiotic Role of theSinorhizobium melilotiExopolysaccharide Succinoglycan". Journal of Bacteriology 200, n.º 13 (9 de abril de 2018): e00665-17. http://dx.doi.org/10.1128/jb.00665-17.
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ABSTRACTSinorhizobium melilotienters into beneficial symbiotic interactions withMedicagospecies of legumes. Bacterial exopolysaccharides play critical signaling roles in infection thread initiation and growth during the early stages of root nodule formation. After endocytosis ofS. melilotiby plant cells in the developing nodule, plant-derived nodule-specific cysteine-rich (NCR) peptides mediate terminal differentiation of the bacteria into nitrogen-fixing bacteroids. Previous transcriptional studies showed that the intensively studied cationic peptide NCR247 induces expression of theexogenes that encode the proteins required for succinoglycan biosynthesis. In addition, genetic studies have shown that someexomutants exhibit increased sensitivity to the antimicrobial action of NCR247. Therefore, we investigated whether the symbiotically activeS. melilotiexopolysaccharide succinoglycan can protectS. melilotiagainst the antimicrobial activity of NCR247. We discovered that high-molecular-weight forms of succinoglycan have the ability to protectS. melilotifrom the antimicrobial action of the NCR247 peptide but low-molecular-weight forms of wild-type succinoglycan do not. The protective function of high-molecular-weight succinoglycan occurs via direct molecular interactions between anionic succinoglycan and the cationic NCR247 peptide, but this interaction is not chiral. Taken together, our observations suggest thatS. melilotiexopolysaccharides not only may be critical during early stages of nodule invasion but also are upregulated at a late stage of symbiosis to protect bacteria against the bactericidal action of cationic NCR peptides. Our findings represent an important step forward in fully understanding the complete set of exopolysaccharide functions during legume symbiosis.IMPORTANCESymbiotic interactions between rhizobia and legumes are economically important for global food production. The legume symbiosis also is a major part of the global nitrogen cycle and is an ideal model system to study host-microbe interactions. Signaling between legumes and rhizobia is essential to establish symbiosis, and understanding these signals is a major goal in the field. Exopolysaccharides are important in the symbiotic context because they are essential signaling molecules during early-stage symbiosis. In this study, we provide evidence suggesting that theSinorhizobium melilotiexopolysaccharide succinoglycan also protects the bacteria against the antimicrobial action of essential late-stage symbiosis plant peptides.
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Tomic, Z., Z. Lugic, J. Radovic, D. Sokolovic, Z. Nesic y V. Krnjaja. "Perennial legumes and grasses stable source of quality livestock fodder feed". Biotehnologija u stocarstvu 23, n.º 5-6-1 (2007): 559–72. http://dx.doi.org/10.2298/bah0701559t.
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Perennial legumes, alfalfa, red clover, bird's foot trefoil, white clover, sainfoin and grasses, cock's foot, meadow fescue, tall fescue, Italian ryegrass, English ryegrass, French ryegrass, red fescue and Timothy grass can be grown successfully in pure crops and in legume-grass mixtures, on different soil types. Their importance in livestock development is based primarily on the great potential for yield of dry matter of over 20 t ha-1 if adequate agro-technical measures have been applied. Also, perennial legumes are characterized with high content of nutritive substances, especially protein and represent the most important protein source in livestock nutrition. Depending on the species and pheno stage of utilization, the content of crude proteins in grasses varies from 100 to 174,6 g kg-1 of DM, and in perennial legumes from 190,0 to 228,8 g kg-1 of DM. Livestock feed obtained from these plant species can be used in several ways, from grazing as most efficient and economical way, to preparation of hay and high quality silages and haylages. Stated forage species are very important in sustainable agriculture and organic production, considering that they carry out the process of biological fixation of nitrogen, but also from the ecological aspect. By using diverse selection/breeding material numerous domestic cultivars of perennial legumes and grasses have been created which are characterized with high potential for main agronomical traits.
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Swarnalakshmi, Karivaradharajan, Vandana Yadav, Deepti Tyagi, Dolly Wattal Dhar, Annapurna Kannepalli y Shiv Kumar. "Significance of Plant Growth Promoting Rhizobacteria in Grain Legumes: Growth Promotion and Crop Production". Plants 9, n.º 11 (17 de noviembre de 2020): 1596. http://dx.doi.org/10.3390/plants9111596.
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Grain legumes are an important component of sustainable agri-food systems. They establish symbiotic association with rhizobia and arbuscular mycorrhizal fungi, thus reducing the use of chemical fertilizers. Several other free-living microbial communities (PGPR—plant growth promoting rhizobacteria) residing in the soil-root interface are also known to influence biogeochemical cycles and improve legume productivity. The growth and function of these microorganisms are affected by root exudate molecules secreted in the rhizosphere region. PGPRs produce the chemicals which stimulate growth and functions of leguminous crops at different growth stages. They promote plant growth by nitrogen fixation, solubilization as well as mineralization of phosphorus, and production of phytohormone(s). The co-inoculation of PGPRs along with rhizobia has shown to enhance nodulation and symbiotic interaction. The recent molecular tools are helpful to understand and predict the establishment and function of PGPRs and plant response. In this review, we provide an overview of various growth promoting mechanisms of PGPR inoculations in the production of leguminous crops.
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Buerkert, A., H. P. Piepho y A. Bationo. "MULTI-SITE TIME-TREND ANALYSIS OF SOIL FERTILITY MANAGEMENT EFFECTS ON CROP PRODUCTION IN SUB-SAHARAN WEST AFRICA". Experimental Agriculture 38, n.º 2 (28 de marzo de 2002): 163–83. http://dx.doi.org/10.1017/s0014479702000236.
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Soil fertility constraints to crop production have been recognized widely as a major obstacle to food security and agro-ecosystem sustainability in sub-Saharan West Africa. As such, they have led to a multitude of research projects and policy debates on how best they should be overcome. Conclusions, based on long-term multi-site experiments, are lacking with respect to a regional assessment of phosphorus and nitrogen fertilizer effects, surface mulched crop residues, and legume rotations on total dry matter of cereals in this region. A mixed model time-trend analysis was used to investigate the effects of four nitrogen and phosphorus rates, annually applied crop residue dry matter at 500 and 2000 kg ha−1, and cereal-legume rotation versus continuous cereal cropping on the total dry matter of cereals and legumes. The multi-factorial experiment was conducted over four years at eight locations, with annual rainfall ranging from 510 to 1300 mm, in Niger, Burkina Faso, and Togo. With the exception of phosphorus, treatment effects on legume growth were marginal. At most locations, except for typical Sudanian sites with very low base saturation and high rainfall, phosphorus effects on cereal total dry matter were much lower with rock phosphate than with soluble phosphorus, unless the rock phosphate was combined with an annual seed-placement of 4 kg ha−1 phosphorus. Across all other treatments, nitrogen effects were negligible at 500 mm annual rainfall but at 900 mm, the highest nitrogen rate led to total dry matter increases of up to 77% and, at 1300 mm, to 183%. Mulch-induced increases in cereal total dry matter were larger with lower base saturation, reaching 45% on typical acid sandy Sahelian soils. Legume rotation effects tended to increase over time but were strongly species-dependent.
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Baloyi, J. J., N. T. Ngongoni y H. Hamudikuwanda. "The effect feeding forage legumes as nitrogen supplement on growth performance of sheep". Tropical Animal Health and Production 40, n.º 6 (11 de enero de 2008): 457–62. http://dx.doi.org/10.1007/s11250-007-9120-3.
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Mullenix, Kim K. y Jennifer J. Tucker. "Economics and Feasibility of Legume Inclusion in Southeastern Perennial Grass-Based Systems". Journal of Animal Science 99, Supplement_2 (1 de mayo de 2021): 35. http://dx.doi.org/10.1093/jas/skab096.063.
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Abstract Perennial grass pastures provide the basis for beef production systems across the Southeast United States. One common management practice that is widely recommended among agronomists is interseeding cool-season legumes. Legumes can serve as a complementary resource for filling in production gaps, reducing supplemental feedstuffs, reducing the need for nitrogen fertilization, increasing the nutritional quality of forage available, increase biomass production, improve animal performance, and can reduce the toxic effects of endophyte-infected tall fescue through dilution. A simulated economic analysis was developed to further the economic understanding of the cost of implementation, the subsequent animal and forage performance benefits, and net returns from the inclusion of legumes over many research trials and years. Data from 15 peer-reviewed papers was used to simulate the economic benefits of implementing this production practice. Cost of production and revenue for each paper were calculated using the 10-year average from 2010 to 2019. This analysis provides users with a further understanding of the net returns, critical breakeven areas, and return on investment that is necessary in order to successfully implement the inclusion of cool-season legumes in perennial grass-based systems.
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Singh, D. K., N. McGuckian, R. A. Routley, G. A. Thomas, R. C. Dalal, Y. P. Dang, T. J. Hall et al. "Poor adoption of ley-pastures in south-west Queensland: biophysical, economic and social constraints". Animal Production Science 49, n.º 10 (2009): 894. http://dx.doi.org/10.1071/an09015.
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The present review identifies various constraints relating to poor adoption of ley-pastures in south-west Queensland, and suggests changes in research, development and extension efforts for improved adoption. The constraints include biophysical, economic and social constraints. In terms of biophysical constraints, first, shallower soil profiles with subsoil constraints (salt and sodicity), unpredictable rainfall, drier conditions with higher soil temperature and evaporative demand in summer, and frost and subzero temperature in winter, frequently result in a failure of established, or establishing, pastures. Second, there are limited options for legumes in a ley-pasture, with the legumes currently being mostly winter-active legumes such as lucerne and medics. Winter-active legumes are ineffective in improving soil conditions in a region with summer-dominant rainfall. Third, most grain growers are reluctant to include grasses in their ley-pasture mix, which can be uneconomical for various reasons, including nitrogen immobilisation, carryover of cereal diseases and depressed yields of the following cereal crops. Fourth, a severe depletion of soil water following perennial ley-pastures (grass + legumes or lucerne) can reduce the yields of subsequent crops for several seasons, and the practice of longer fallows to increase soil water storage may be uneconomical and damaging to the environment. Economic assessments of integrating medium- to long-term ley-pastures into cropping regions are generally less attractive because of reduced capital flow, increased capital investment, economic loss associated with establishment and termination phases of ley-pastures, and lost opportunities for cropping in a favourable season. Income from livestock on ley-pastures and soil productivity gains to subsequent crops in rotation may not be comparable to cropping when grain prices are high. However, the economic benefits of ley-pastures may be underestimated, because of unaccounted environmental benefits such as enhanced water use, and reduced soil erosion from summer-dominant rainfall, and therefore, this requires further investigation. In terms of social constraints, the risk of poor and unreliable establishment and persistence, uncertainties in economic and environmental benefits, the complicated process of changing from crop to ley-pastures and vice versa, and the additional labour and management requirements of livestock, present growers socially unattractive and complex decision-making processes for considering adoption of an existing medium- to long-term ley-pasture technology. It is essential that research, development and extension efforts should consider that new ley-pasture options, such as incorporation of a short-term summer forage legume, need to be less risky in establishment, productive in a region with prevailing biophysical constraints, economically viable, less complex and highly flexible in the change-over processes, and socially attractive to growers for adoption in south-west Queensland.
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Young, Douglas L. "Policy barriers to sustainable agriculture". American Journal of Alternative Agriculture 4, n.º 3-4 (diciembre de 1989): 135–43. http://dx.doi.org/10.1017/s0889189300002964.
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AbstractU.S. agriculture, which has developed in a mixed environment of private initiative and government support, is very successful by many measures. American farmers produce record levels of food and fiber per farm worker at very low budgetary cost to consumers. Recently, however, concern about resource depletion and agrichemical pollution has caused critics to question the environmental sustainability of the agricultural production system. Furthermore, pressures to trim the growing contribution of agricultural subsidies to the national budget deficit have led legislators and others to question the sustainability of the federal farm programs. Low agrichemical input or sustainable agricultural practices, such as nitrogen-fixing legumes in rotation with cereals, could reduce environmental damage. The selectivity and structure of historical farm programs, however, have economically favored conventional systems. Farm programs subsidize only about half the total value of agricultural products. Feed and food grains, cotton, and dairy products receive the lion's share of payments. Soil-building crops like forage legumes, most edible legumes, hay, and pasture are excluded. Secondly, the structure of commodity programs favors intensive production of program crops supported by high fertilizer and pesticide applications. This incentive emanates from the policy of computing the farm-wide deficiency payment for a program crop proportionately to the farm's historical “base” acreage and “established” yield for the crop. The leading farm program crops of corn, wheat, cotton, and soybeans occupied slightly over 60 percent of cropped acres and received at least 65 percent of all U.S. agricultural pesticides and fertilizer in the mid 19809s. Despite budget pressures and environmental concerns, near term termination of farm programs or decoupling them from production of particular commodities is unlikely. Fears about aggravating financial stress, reducing land values, and harming agrichemical supply businesses in program crop-growing regions will promote cautious incremental change. Recent promising signs of “creeping decoupling” include the 1986 freeze on established yields, the gradual reduction in target prices, the permitting of multi-year grass or legume plantings as set aside acreage, and the loosening of base acreage restrictions within the 1988 Drought Relief Bill.
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Savage, Joanna, Ben A. Woodcock, James M. Bullock, Marek Nowakowski, Jeremy R. B. Tallowin y Richard F. Pywell. "Management to Support Multiple Ecosystem Services from Productive Grasslands". Sustainability 13, n.º 11 (1 de junio de 2021): 6263. http://dx.doi.org/10.3390/su13116263.
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Sustainable intensification will require the development of new management systems to support global food demands, whilst conserving the integrity of ecosystem functions. Here, we test and identify management strategies to maintain or enhance agricultural production in grasslands whilst simultaneously supporting the provision of multiple ecosystem services. Over four years, we investigated how the establishment of three plant functional groups (grasses, legumes, and other flowering forbs), using different cultivation (minimum tillage and deep ploughing) and management (cutting, grazing and their intensity) techniques, affected provision and complementarity between key ecosystem services. These ecosystem services were agronomic production, pollination, pest control, food resources for farmland birds, and soil services. We found that the establishment of floristically diverse swards, particularly those containing grasses, legumes and forbs, maximised forage yield and quality, pollinator abundance, soil nitrogen, and bird food resources, as well as enhancing populations of natural predators of pests. Cutting management increased bird food resources and natural predators of pests without depleting other services considered. However, a single management solution to maximise the delivery of all ecosystem services is unlikely to exist, as trade-offs also occurred. Consequently, management options may need to be tailored to strategically support localised deficits in key ecosystem services.
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Espindola, J. A. A., J. G. M. Guerra, D. L. Almeida, M. G. Teixeira y S. Urquiaga. "Evaluation of perennial herbaceous legumes with different phosphorus sources and levels in a Brazilian Ultisol". Renewable Agriculture and Food Systems 20, n.º 1 (marzo de 2005): 56–62. http://dx.doi.org/10.1079/raf200492.
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AbstractThis study was carried out under field conditions with the aim of evaluating the period of time necessary for soil cover, dry matter production and accumulation of nutrients by perennial herbaceous legumes with different phosphorus sources at different levels. Four legumes were evaluated: calopo (Calopogonium mucunoides Desv.), forage groundnut (Arachis pintoi Krap. & Greg.), siratro (Macroptilium atropurpureum (OC.) Urb.) and tropical kudzu (Pueraria phaseoloides (Roxb.) Benth.). Each of these species received different phosphorus (P) sources and levels: no phosphate fertilization; 44 and 88 kg of P ha−1 applied as rock phosphate; and 44 kg of P ha−1 as triple superphosphate. Calopo, siratro and tropical kudzu completely covered the soil surface 129 days before forage groundnut. Phosphate fertilization did not increase the dry matter production of any species. The legumes forage groundnut, siratro and tropical kudzu showed desirable characteristics that promote their use as cover crops, such as high dry matter production and shoot accumulation of nitrogen (N) and potassium (K). Forage groundnut had the highest proportion of N derived from the atmosphere at the end of the rainy season, while there were no significant differences between the legumes at the end of the dry season. There was an elevation of soil pH and calcium+magnesium (Ca+Mg) contents, associated with a reduction of aluminum (Al) content, in the surface soil layer (0–5 cm) for siratro in relation to groundnut and tropical kudzu. Tropical kudzu promoted higher soil organic C contents when compared to groundnut.
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James, Euan K. y J. Ivo Baldani. "The role of biological nitrogen fixation by non-legumes in the sustainable production of food and biofuels". Plant and Soil 356, n.º 1-2 (9 de junio de 2012): 1–3. http://dx.doi.org/10.1007/s11104-012-1317-1.
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Roriz, Mariana, Susana M. P. Carvalho, Paula M. L. Castro y Marta W. Vasconcelos. "Legume Biofortification and the Role of Plant Growth-Promoting Bacteria in a Sustainable Agricultural Era". Agronomy 10, n.º 3 (22 de marzo de 2020): 435. http://dx.doi.org/10.3390/agronomy10030435.
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World population growth, together with climate changes and increased hidden hunger, bring an urgent need for finding sustainable and eco-friendly agricultural approaches to improve crop yield and nutritional value. The existing methodologies for enhancing the concentration of bioavailable micronutrients in edible crop tissues (i.e., biofortification), including some agronomic strategies, conventional plant breeding, and genetic engineering, have not always been successful. In recent years, the use of plant growth-promoting bacteria (PGPB) has been suggested as a promising approach for the biofortification of important crops, including legumes. Legumes have many beneficial health effects, namely, improved immunological, metabolic and hormonal regulation, anticarcinogenic and anti-inflammatory effects, and decreased risk of cardiovascular and obesity-related diseases. These crops also play a key role in the environment through symbiotic nitrogen (N) fixation, reducing the need for N fertilizers, reducing CO2 emissions, improving soil composition, and increasing plant resistance to pests and diseases. PGPB act by a series of direct and indirect mechanisms to potentially improve crop yields and nutrition. This review will focus on the: (i) importance of legumes in the accomplishment of United Nations Sustainable Development Goals for production systems; (ii) understanding the role of PGPB in plant nutrition; (iii) iron biofortification of legumes with PGPB, which is an interesting case study of a green technology for sustainable plant-food production improving nutrition and promoting sustainable agriculture.
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Lazali, Mohamed, Simon Boudsocq, Elisa Taschen, Mohamed Farissi, Wissem Hamdi, Parthenopi Ralli y Hervé Sentenac. "CROSYMED Project: Enhancing Nutrient Use Efficiency through Legumes in Agroecosystems of the Mediterranean Basin". Sustainability 13, n.º 9 (22 de abril de 2021): 4695. http://dx.doi.org/10.3390/su13094695.
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Modern intensive agricultural systems generally focus on the productivity of monocultures. They are characterized by a low diversity of crops, with uniform and symmetrical planting layouts. They largely rely on the utilization of chemical inputs. They are widely denounced for their negative environmental impacts. In this context, the ecological intensification framework proposes the exploitation of biodiversity in order to better achieve such ecosystem services and soil conservation. Intercropping, i.e., the simultaneous growth of two or more crops mixed in the same field, appears to have the potentialities to improve the productivity, resilience capacity, and ecological sustainability of agroecosystems through the intensification of such positive interactions between plants as facilitation and niche complementarity. Cereal–legume intercropping turns out to be effective in low-N agroecosystems, since legumes have the ability to fix atmospheric nitrogen via their symbiosis with rhizobia. This fixed N, in turn, benefits the cereal through various ecological processes. The objective of the project is to improve the benefit of legumes for intercropped cereals in low-input agroecosystems through the management of plant–plant and plant–microbe interactions. The nitrogen-fixing symbiosis requires phosphorus and iron to be efficient. While these nutrients are prone to be lacking in N-limited agroecosystems, as is the case in Mediterranean agroecosystems, plant–plant interactions and rhizobacteria and mycorrhiza interactions seem to play an important role in their acquisition and efficient utilization. We propose the development of a participatory research project in four Mediterranean agroecosystems. Agronomic and environmental diagnosis will be performed in the field to assess N and P biogeochemical cycles, as well as Fe availability, in combination with the plant performances and the diversity of soil microorganisms. Molecular identification of soil microorganisms from the most productive sites will be done and research of genes for tolerance to Fe- and P-deficiencies will be realized. Glasshouse experiments involving various cultivars of cereals and legumes, as well as the previously identified microorganisms, will be done in order to disentangle the various mechanisms of nutrient acquisition, sharing, and transfer between plants. Other experiments will assess the effects of cereal–legume–microbe interactions on the development and architecture of the plant root systems and root hair development. The lines of research are integrated with a strategy of functional ecology on plant–microbe–soil interactions in the agroecosystems of Gabès (Tunisia), Boumedfaa (Algeria), Beni Mellal (Morocco), and Thessaloniki (Greece). Using multidisciplinary and innovative approaches, the program will provide novel knowledge and understanding of agroecosystem management for food production.
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Suzuki, Shino, Toshihiro Aono, Kyung-Bum Lee, Tadahiro Suzuki, Chi-Te Liu, Hiroki Miwa, Seiji Wakao, Taichiro Iki y Hiroshi Oyaizu. "Rhizobial Factors Required for Stem Nodule Maturation and Maintenance in Sesbania rostrata-Azorhizobium caulinodans ORS571 Symbiosis". Applied and Environmental Microbiology 73, n.º 20 (24 de agosto de 2007): 6650–59. http://dx.doi.org/10.1128/aem.01514-07.
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ABSTRACT The molecular and physiological mechanisms behind the maturation and maintenance of N2-fixing nodules during development of symbiosis between rhizobia and legumes still remain unclear, although the early events of symbiosis are relatively well understood. Azorhizobium caulinodans ORS571 is a microsymbiont of the tropical legume Sesbania rostrata, forming N2-fixing nodules not only on the roots but also on the stems. In this study, 10,080 transposon-inserted mutants of A. caulinodans ORS571 were individually inoculated onto the stems of S. rostrata, and those mutants that induced ineffective stem nodules, as displayed by halted development at various stages, were selected. From repeated observations on stem nodulation, 108 Tn5 mutants were selected and categorized into seven nodulation types based on size and N2 fixation activity. Tn5 insertions of some mutants were found in the well-known nodulation, nitrogen fixation, and symbiosis-related genes, such as nod, nif, and fix, respectively, lipopolysaccharide synthesis-related genes, C4 metabolism-related genes, and so on. However, other genes have not been reported to have roles in legume-rhizobium symbiosis. The list of newly identified symbiosis-related genes will present clues to aid in understanding the maturation and maintenance mechanisms of nodules.
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Mora, Yolanda, Rafael Díaz, Carmen Vargas-Lagunas, Humberto Peralta, Gabriela Guerrero, Alejandro Aguilar, Sergio Encarnación, Lourdes Girard y Jaime Mora. "Nitrogen-Fixing Rhizobial Strains Isolated from Common Bean Seeds: Phylogeny, Physiology, and Genome Analysis". Applied and Environmental Microbiology 80, n.º 18 (7 de julio de 2014): 5644–54. http://dx.doi.org/10.1128/aem.01491-14.
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ABSTRACTRhizobial bacteria are commonly found in soil but also establish symbiotic relationships with legumes, inhabiting the root nodules, where they fix nitrogen. Endophytic rhizobia have also been reported in the roots and stems of legumes and other plants. We isolated several rhizobial strains from the nodules of noninoculated bean plants and looked for their provenance in the interiors of the seeds. Nine isolates were obtained, covering most known bean symbiont species, which belong to theRhizobiumandSinorhizobiumgroups. The strains showed several large plasmids, except for aSinorhizobiumamericanumisolate. Two strains, oneRhizobium phaseoliand oneS. americanumstrain, were thoroughly characterized. Optimal symbiotic performance was observed for both of these strains. TheS. americanumstrain showed biotin prototrophy when subcultured, as well as high pyruvate dehydrogenase (PDH) activity, both of which are key factors in maintaining optimal growth. TheR. phaseolistrain was a biotin auxotroph, did not grow when subcultured, accumulated a large amount of poly-β-hydroxybutyrate, and exhibited low PDH activity. The physiology and genomes of these strains showed features that may have resulted from their lifestyle inside the seeds: stress sensitivity, a ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) complex, a homocitrate synthase (usually present only in free-living diazotrophs), a hydrogenase uptake cluster, and the presence of prophages. We propose that colonization by rhizobia and their presence inPhaseolusseeds may be part of a persistence mechanism that helps to retain and disperse rhizobial strains.
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Qiao, Yunfa, Shujie Miao, Jian Jin, Ulrike Mathesius y Caixian Tang. "Differential responses of the sunn4 and rdn1-1 super-nodulation mutants of Medicago truncatula to elevated atmospheric CO2". Annals of Botany 128, n.º 4 (23 de julio de 2021): 441–52. http://dx.doi.org/10.1093/aob/mcab098.
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Abstract Background and Aims Nitrogen fixation in legumes requires tight control of carbon and nitrogen balance. Thus, legumes control nodule numbers via an autoregulation mechanism. ‘Autoregulation of nodulation’ mutants super-nodulate are thought to be carbon-limited due to the high carbon-sink strength of excessive nodules. This study aimed to examine the effect of increasing carbon supply on the performance of super-nodulation mutants. Methods We compared the responses of Medicago truncatula super-nodulation mutants (sunn-4 and rdn1-1) and wild type to five CO2 levels (300–850 μmol mol−1). Nodule formation and nitrogen fixation were assessed in soil-grown plants at 18 and 42 d after sowing. Key Results Shoot and root biomass, nodule number and biomass, nitrogenase activity and fixed nitrogen per plant of all genotypes increased with increasing CO2 concentration and reached a maximum at 700 μmol mol−1. While the sunn-4 mutant showed strong growth retardation compared with wild-type plants, elevated CO2 increased shoot biomass and total nitrogen content of the rdn1-1 mutant up to 2-fold. This was accompanied by a 4-fold increase in nitrogen fixation capacity in the rdn1-1 mutant. Conclusions These results suggest that the super-nodulation phenotype per se did not limit growth. The additional nitrogen fixation capacity of the rdn1-1 mutant may enhance the benefit of elevated CO2 for plant growth and N2 fixation.
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Hossain, Akbar, Sunil Kumar Gunri, Manashi Barman, Ayman EL Sabagh y Jaime A. Teixeira da Silva. "Isolation, characterization and purification of Rhizobium strain to enrich the productivity of groundnut (Arachis hypogaea L.)". Open Agriculture 4, n.º 1 (19 de julio de 2019): 400–409. http://dx.doi.org/10.1515/opag-2019-0040.
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AbstractGroundnut (Arachis hypogaea L.) is an important food legume in tropical and subtropical areas because of its ability to adapt to a wide range of agro-climatic regions. Groundnut is usually cultivated in nutrient-poor soil and rain-fed conditions, so average yield tends to be very low relative to potential yield. Even though the nitrogen (N) requirement of groundnut is much higher than cereals due to its high protein content, it has the capacity to meet 60-80% of N-based requirements through symbiotic N fixation via its root nodules. In its symbiotic relationship with legumes, Rhizobium fixes N, thereby positively impacting the content of this nutrient. This study aimed to isolate, characterize and purify microbial strains of Rhizobium specific to groundnut in a bid to increase this legume’s productivity. The research was conducted in the AICRP-Groundnut laboratory and greenhouse of the Directorate of Research, BCKV, in Kalyani, India during October 2016 to March 2017. Two Rhizobium isolates (RhBC and NRA1) were isolated and selected from groundnut pot cultures. After 45 days, NRA1 produced higher plant biomass, longer roots and shoots, more nodules and higher nodule dry weight than RhBC. NRA1 was selected for a future field trial. The two isolated microbial strains will aid in the screening of additional local isolates to test their effectiveness when co-cultured with local groundnut cultivars to increase yield in soil with low fertility.