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Adopting eco‐friendly diets will demand the consumption of more plant‐based protein food sources such as legumes. However, assessing the impact of such a dietary shift on the dietary and nutritional intake of traditionally omnivorous populations is needed. The objective of this study was to assess the impact of substituting a traditional omnivorous‐based lunch for a vegetarian, legume‐based meal on the daily dietary and nutritional intake in a group of omnivorous adults in the city of Porto, Portugal. Nineteen, non‐vegetarian, healthy young adults consumed a vegetarian, legume‐based meal from Monday to Friday, for 8 consecutive weeks. Socio‐demographic data, health status, lifestyle‐related information and anthropometric parameters were recorded. Three‐day food records were used to collect food intake at baseline and week 8. European Food Safety Authority and World Health Organization reference values were used to assess nutritional inadequacies. Variables were described as medians (P25 and P75). Wilcoxon signed‐rank and Mann–Whitney tests were used for statistical comparisons. A p‐value of <0.05 was considered statistically significant. Participants consumed 38.0 (P25 = 35.0; P75 = 40.0) meals, resulting in an intake of 84.5 g (P25 = 74.9; P75 = 98.4) of cooked legumes per meal, meaning 11 subjects (57.9%) met the Portuguese guidelines for legume consumption (≥80 g/day of legumes). The current dietary intervention did not seem to aggravate the prevalence of nutritional inadequacies for the macro‐ and micronutrients tested, except for the case of vitamin B12 (52.6% [95% CI: 28.9–75.6] vs. 78.9% [95% CI: 54.4–94.0]). This could be linked to the reduction of dietary sources of this vitamin which is an expected consequence of vegetarian meals. Dietary changes towards grain legume‐based diets are desirable yet need to be carefully implemented to prevent exacerbating potential nutrient inadequacies, especially of vitamin B12. [ABSTRACT FROM AUTHOR]

BACKGROUND The protein‐rich fractions of pulses and pseudocereals exhibit a well‐balanced amino acid profile, particularly when combined in different portions, and are therefore high‐value ingredients for the production of extruded snacks. However, the impact of a combination of pulses and pseudocereals on the physical and sensory qualities of extruded snacks has not been investigated up to now. Native or preconditioned protein isolates and concentrates from pulses – as single ingredients or in combination with protein‐rich flours of pseudocereals – were analyzed regarding their thermal and functional properties in relation to extrusion characteristics. Low moisture extrusion cooking was used to investigate the impact of protein source (lentil, lupin, faba bean), pseudocereal source (quinoa, amaranth, buckwheat) and protein content (30%, 50%, 70%) on sectional expansion, specific hardness, density and sensory properties of the snacks. RESULTS: With increasing protein content from 30% to 50%, the sectional expansion decreased and the density and specific hardness of the extrudates increased, which could be counteracted by preconditioning of the protein‐rich ingredients. Lupin protein‐based extrudates exhibited satisfactory texture and sensory properties. Extruded mixtures of pulses and pseudocereals (70% protein) exhibited a smaller sectional expansion compared to pulses as single ingredients (30%, 50%), regardless of pseudocereal type. However, the texture and sensory properties of the extruded blends were satisfactory. CONCLUSIONS: We show for the first time that protein‐rich fractions of pulses and pseudocereals can be processed into expanded snacks with favorable texture and nutritional properties such as increased protein contents (70%) and balanced amino acid profiles. © 2020 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Legumes play a key role in food and nutrition security, providing livestock feed and contributing to soil fertility, in mixed smallholder farms in sub‐Saharan Africa (SSA). The environmental conditions under which smallholder farming is practiced are highly heterogeneous with large differences in management practices among farms resulting in variable legume productivity. A meta‐analysis based on 128 publications was conducted to quantify the effects of intercropping, inoculation with rhizobia, minimum tillage and phosphorus application on legume grain and biomass yield and the amount of biological nitrogen fixation in a range of SSA contexts. To further explain the heterogeneity in the results, legume species, type of inoculant, P‐application rate, altitude, rainfall, soil characteristics and non‐legume companion crops were used as moderators. Intercropping as compared to sole cropping reduced legume biomass and grain yields to varying extents, although the total land equivalent ratio for the sum of the intercrops was higher than 1 (1.2–1.9) in all cases. Expressed as the relative land equivalent ratio (rLER) intercropping affected pigeonpea grain yield the least (rLER 0.9) and faba bean the most (rLER 0.3). The non‐legume companion crops explained some of the heterogeneity where maize and sorghum significantly reduced the legume yields. Inoculation and P application increased legume grain and biomass yield and moderators such as legume species, type of inoculant, soil organic carbon and soil pH further explained the different effects of the management practices on legume productivity. Minimum tillage had no effect on legume productivity, although less data were available than for the other practices. We conclude that intercropping with legumes improves overall productivity and that application of P fertilizer and inoculants increase legume grain and biomass yield. The effect varies with crop species, soil type and other environmental conditions, and this needs to be factored into tailored recommendations supporting decision making in smallholder farming. [ABSTRACT FROM AUTHOR]

Concerns about insect declines are growing and the provisioning of ecosystem services like pollination may be threatened. To safeguard biodiversity, greening measures were introduced within the reform of the EU's Common Agricultural Policy. One measure commonly applied by farmers is the cultivation of nitrogen fixing crops. Although underlying studies are largely missing, this measure is criticized as providing no significant biodiversity benefit.Using a landscape‐scale approach, we selected 30 paired study landscapes (1 km × 1 km) in Germany, that is, 15 study landscapes with faba bean (FB) fields (Vicia faba L.) and 15 without any grain legumes. Flower‐visiting wild bees were recorded with transect walks at the field margins of different crops using a stratified sampling approach. We analysed the effect of FB cultivation and landscape composition on the abundance and species richness of wild bees as well as on the functional composition of the bee communities.Bumblebee densities (Bombus spp. Latreille) were more than twice as high in FB compared to control landscapes after the flowering of the beans. Non‐Bombus wild bee densities, however, were not affected by FB cultivation, but were enhanced by increasing amounts of semi‐natural habitats (SNH).After the beans' blooming had ceased, FB landscapes had a higher proportion of wild bees collecting pollen from Fabaceae than control landscapes. The community‐weighted means for bee size, measured as intertegular distance, were not affected by FB cultivation, but we found smaller species and species with shorter tongues with an increasing percentage of SNH.Synthesis and applications. The cultivation of faba bean Vicia faba L. strongly increased bumblebee densities throughout the season. This indicates that also on‐field greening measures can support biodiversity. Nevertheless, since only functional groups adapted to faba bean benefit, measures to promote semi‐natural habitats in agricultural landscapes need to be implemented. We conclude that the combination of on‐ and off‐field measures is essential to maintain farmland biodiversity and the Common Agricultural Policy should furthermore promote both. [ABSTRACT FROM AUTHOR]

Legumes are important components of sustainable agricultural production, food, nutrition and income systems of developing countries. In spite of their importance, legume crop production is challenged by a number of biotic (diseases and pests) and abiotic stresses (heat, frost, drought and salinity), edaphic factors (associated with soil nutrient deficits) and policy issues (where less emphasis is put on legumes compared to priority starchy staples). Significant research and development work have been done in the past decade on important grain legumes through collaborative bilateral and multilateral projects as well as the CGIAR Research Program on Grain Legumes (CRP‐GL). Through these initiatives, genomic resources and genomic tools such as draft genome sequence, resequencing data, large‐scale genomewide markers, dense genetic maps, quantitative trait loci (QTLs) and diagnostic markers have been developed for further use in multiple genetic and breeding applications. Also, these mega‐initiatives facilitated release of a number of new varieties and also dissemination of on‐the‐shelf varieties to the farmers. More efforts are needed to enhance genetic gains by reducing the time required in cultivar development through integration of genomics‐assisted breeding approaches and rapid generation advancement. [ABSTRACT FROM AUTHOR]

During soil waterlogging, plants experience O2 deficits, elevated ethylene, and high CO2 in the root‐zone. The effects on chickpea (Cicer arietinum L.) and faba bean (Vicia faba L.) of ethylene (2 μL L−1), CO2 (2–20% v/v) or deoxygenated stagnant solution were evaluated. Ethylene and high CO2 reduced root growth of both species, but O2 deficiency had the most damaging effect and especially so for chickpea. Chickpea suffered root tip death when in deoxygenated stagnant solution. High CO2 inhibited root respiration and reduced growth, whereas sugars accumulated in root tips, of both species. Gas‐filled porosity of the basal portion of the primary root of faba bean (23%, v/v) was greater than for chickpea (10%), and internal O2 movement was more prominent in faba bean when in an O2‐free medium. Ethylene treatment increased the porosity of roots. The damaging effects of low O2, such as death of root tips, resulted in poor recovery of root growth upon reaeration. In conclusion, ethylene and high CO2 partially inhibited root extension in both species, but low O2 in deoxygenated stagnant solution had the most damaging effect, even causing death of root tips in chickpea, which was more sensitive to the low O2 condition than faba bean. Roots in waterlogged soil can experience O2 deficits, elevated ethylene, and high CO2. Faba bean was more tolerant than chickpea, to growth in stagnant deoxygenated nutrient solution, as the gas‐filled porosity and internal O2 movement were greater in the roots of faba bean than in chickpea. Ethylene (2 μL L−1) and high CO2 (2–20% v/v) each reduced root growth of both species, and high CO2 inhibited root respiration. Thus, ethylene and high CO2 can partially inhibit root growth, but low O2 had the most damaging effect on the roots of these cool‐season grain legume species. [ABSTRACT FROM AUTHOR]

A major challenge of our time is to produce sufficient nutrient‐rich food for the ever‐growing human population with limited land resources. There is a huge gap between current yields and genetic potential in many crops, which can be narrowed by enhancing land productivity. High‐input cropping increases crop yields, but heavy fertilizer and pesticide use can lead to land degradation, increase greenhouse gas footprint, and carry significant risks for eutrophication. What efforts can be taken to 'decouple' land productivity and the environmental footprint? Can land productivity increase while concurrently minimizing the environmental footprint? Here, we show that an integrated systems approach can minimize the tradeoff to achieve an effective 'decoupling' outcome. Some key components that can be integrated into a system include (i) intensifying crop rotations to enhance carbon conversion from atmospheric CO2 to plant biomass, (ii) diversifying cropping systems to enhance residual soil water and nutrient use and increase systems resilience, (iii) including N2‐fixing pulse crops in rotations to reduce synthetic fertilizer use, (iv) improving fertilizer‐N use efficiency to lower N2O emissions, and (v) sequestering more carbon to the soil to potentially offset CO2 equivalent emissions from cropping inputs. Integration of these proven cropping practices into a system creates a powerful synergy among individual components, thereby improving land productivity and systems resilience for long‐term sustainability. Relevant economic and agro‐environmental policies are needed to reinforce the adoption of a systems approach at the local farm level. [ABSTRACT FROM AUTHOR]

Summary: Stem growth habit is a key plant architecture trait determining yield potential in grain legumes, and the phenotypic change from the indeterminate stem growth habit of wild mungbeans (Vigna radiata) to the determinate stem growth habit of cultivated mungbeans is a critical domestication transition. Here we show that indeterminate stem growth in wild mungbean is modulated by a single gene, VrDet1, which encodes a signaling protein of shoot apical meristems. The transition from an indeterminate to a determinate stem growth habit was achieved by selection of two linked point mutations in two putative cis‐regulatory elements, resulting in a significant reduction in gene expression. Both the wild‐type nucleotides corresponding to the two point mutations were essential for VrDet1 function. In addition, two highly diverse haplotypes of Vrdet1 were found in cultivated mungbeans, suggesting dual domestication of Vrdet1. VrDet1 was orthologous to Dt1 in wild soybean and PvTFL1y in wild common bean, where multiple loss‐of‐function mutations altering the coding sequences of individual genes were selected to produce determinate stems in cultivated accessions. Interspecific comparison of these orthologs in the wild and cultivated accessions reveals the most conservative interspecific and intraspecific parallel domestication events with the broadest mutational spectrum of a domestication trait in leguminous crops. We also found that interspecifically and functionally conserved promoters possess cis‐regulatory elements that are highly conserved in kind but greatly variable in number and order, demonstrating the evolutionary dynamics of regulatory sequences. This work provides insights into the origins of cultivated mungbean and exemplifies the conservativeness and plasticity of the domestication processes of related crops. Significance Statement: This work addresses fundamental questions regarding the origins and domestication processes of cultivated mungbean by elucidating the genetic and molecular bases of stem growth habit, illustrating the conservativeness and plasticity of crop domestication. The findings lay a foundation for dissection of the regulatory mechanisms underlying stem growth habit and other agronomic traits with which it interacts, with the aim of optimizing plant architecture for enhanced yield potential and environmental adaptability. [ABSTRACT FROM AUTHOR]

Abstract: On‐farm evaluation of 15 common bean varieties was undertaken with nine farmer groups under two fertilizer applications levels in four subcounties of Hoima and Rakai districts for two seasons to select farmers’ desired and undesired varieties. Farmers’ votes for acceptance and rejection of varieties at podding stage were converted to a preference index, and analysis of variance was conducted to examine differences in farmers’ preference indices among subcounties and combined across subcounties, seasons, management and gender. Management had no‐significant influence on the way farmers selected varieties in the subcounties. Choice of varieties varied significantly (p ≤ .001) between seasons and gender in the different subcounties. Variety Masindi Yellow Long and Farmers’ seed (Kaduli), and the introduced KATB1 were accepted by farmers due to their medium seed size, desired seed colour and potential of varietal adaptability to their farm conditions. Varieties NABE2, ROBA1 and RWR719 were deselected due to possession of traits less desired in the market. These results demonstrate the need for breeding programmes to involve diverse stakeholders in capturing the diverse traits preferences in varietal development process. [ABSTRACT FROM AUTHOR]

Abstract: Two trials were carried out to evaluate the apparent digestibility coefficients (ADCs) of dry matter (DM), crude protein (CP), lipids, starch and gross energy (GE) of six European varieties of grain legumes, namely chickpea‐type Kabuli (CHK), chickpea‐type Desi (CHD), field pea (FP), faba bean (FB), white lupin (WL) and chickling vetch (CV), in rainbow trout and Nile tilapia juveniles. The ADCs were measured using a reference diet and six experimental diets (700 g/kg of the reference diet and 300 g/kg of each raw grain legume) containing 10 g/kg chromic oxide as inert marker. Additionally, grain legumes were analysed for the organic acids profile. In rainbow trout, FP presented the highest ADCs of DM, CP and GE, whereas chickpeas and FB had the lowest DM, GE and starch ADC values. In Nile tilapia, the lowest values of nutrients (except starch) and energy ADCs were found for FP and CV. Nutrients and energy of chickpeas, WL and FB were better digested by tilapia, whereas FP was better digested by trout. Overall results reveal raw grain legumes as promising feed sources for both fish species. [ABSTRACT FROM AUTHOR]

Grain legumes serve as key sources of dietary protein to the global human population. Consequence of high-temperature ( HT) stress is increasingly evident as drastically lost production of different crops including grain legumes worldwide, thus putting the global food security under great threat. In a changing climate scenario, cool season-adapted grain legumes frequently encounter heat stress ( HS) during their reproductive phase, thus witnessing serious yield losses. To combat the emerging challenges of HT stress, an integrated approach demanding collaborative efforts from various disciplines of plant science should be in place. This review summarizes major impacts of HT stress on grain legume, and captures the relevance of crop genetic resources to HS tolerance in these crops. Measurement of physiological traits assumes key place in view of ever-increasing precision of next-generation phenotyping assays. We also discuss the significance of genetic inheritance and QTL discovery and evolving 'omics' science for developing HS tolerance grain legume crops. [ABSTRACT FROM AUTHOR]

Male sexual aggregations are a common territorial, mating-related or resource-based, behaviour observed in diverse organisms, including insects such as thrips. The influence of factors such as plant substrate, time of day, and geographic location on aggregation of thrips is uncertain, therefore we monitored the dispersion of male and female bean flower thrips (BFT), Megalurothrips sjostedti (Trybom) (Thysanoptera: Thripidae), on cowpea, Vigna unguiculata (L.) Walp. (Fabaceae), over three cowpea growth stages and across three cowpea-growing areas of Kenya. Our results indicated that for all the crop growth stages, the density of BFTs varied over the time of day, with higher densities at 10:00, 13:00, and 16:00 hours than at 07:00 hours. Thrips densities did not differ among blocks at the budding stage, but they did at peak flowering and podding stages. Dispersion indices suggested that both male and female BFTs were aggregated. Active male aggregation occurred only on green plant parts and it varied across blocks, crop stages, and locations. Similarly, active female aggregation was observed in peak flowering and podding stages. Such active aggregation indicates a semiochemical or behaviour-mediated aggregation. Identification of such a semiochemical may offer new opportunities for refining monitoring and management strategies for BFT on cowpea, the most important grain legume in sub-Saharan Africa. [ABSTRACT FROM AUTHOR]

BACKGROUND: The effect of spatial separation of the semiochemical Lurem-TR, which has been found to inhibit conidia of entomopathogenic fungi when put together, on the persistence of conidia of Metarhizium brunneum and M. anisopliae was evaluated in the greenhouse and field in order to develop an autodissemination strategy for the management of Megalurothrips sjostedti on cowpea crop. Influence of spatial separation of the semiochemical on thrips attraction and conidial acquisition by thrips from the autoinoculation device was also investigated in the field. RESULTS: Persistence of conidia of M. brunneum and M. anisopliae increased with distance of separation of Lurem-TR. Direct exposure of fungus without separation from Lurem-TR recorded the lowest conidial germination as compared with the other treatments. Attraction of thrips to the device also varied significantly according to distance between device and semiochemical, with a higher number of thrips attractedwhen Lurem-TRwas placed in a container belowthe device and at 10cmdistance. There was no significant difference in conidial acquisition between spatial separation treatments of conidia and Lurem-TR. Attraction of other insect pests to the device did not significantly vary between treatments. Positive correlations were found between conidial acquisition and thrips attraction. CONCLUSION: This study suggests that spatial separation of fungal conidia from Lurem-TR in an autoinoculation device could provide a low-cost strategy for effective management of thrips in grain legume cropping systems. [ABSTRACT FROM AUTHOR]

Adaptation to one novel host plant may simultaneously improve an insect's performance on other unfamiliar hosts, as a kind of cross-adaptation. In selection experiments using an Asian population of the seed beetle Callosobruchus maculatus ( Fabricius) ( Coleoptera: Chrysomelidae: Bruchinae), larval survival in lentil seeds increased from about 1 to >90% in fewer than 30 generations, and acceptance of lentil by egg-laying females increased two- to three-fold. We examined whether rapid adaptation to lentil altered beetle performance on other grain legumes, including hosts more closely related to lentil than to the ancestral host, mung bean. Three replicate, lentil-adapted lines were compared to the mung-bean (control) line with respect to both host acceptance (oviposition under no-choice conditions) and larval performance (survival to adult emergence, development time, and adult mass at emergence). In most experiments, females from the lentil lines laid more eggs on unfamiliar hosts than did females from the mung-bean line. Greater oviposition on novel hosts could not be explained by variation in potential fecundity, and did not appear to depend on a host's relatedness to lentil. Although survival in lentil remained extremely divergent between the mung-bean and lentil lines (0 vs. >90%), the lines did not differ in larval performance on two other novel hosts (pea and fava bean) that are much more closely related to lentil than to mung bean. Because larval performance is most likely the limiting factor in the potential colonization of a novel host by C. maculatus, our experiments did not provide strong evidence for cross-adaptation. The results suggest that adaptation to even a highly marginal host need not lead to a general expansion of an insect's host range. [ABSTRACT FROM AUTHOR]

Contents [ABSTRACT FROM AUTHOR]

With 2 figures and 3 tables Paucity of polymorphic molecular markers in pigeonpea, Cajanus cajan (L.) Millsp., has been a major limiting factor in application of molecular tools for its genetic improvement. As the development of microsatellite markers requires considerable time, expertise and research infrastructure, transfer of markers from other related genera offers an alternative option to increase the number of available markers. Since microsatellite sequences are conserved across Fabaceae taxa, transferability of 100 chickpea ( Cicer arietinum L.)-specific SSR markers was studied in two genotypes each of five wild and one cultivated species of Cajanus. The results revealed a significant transferability (46%) of chickpea microsatellites to Cajanus. In cultivated pigeonpea, chickpea-specific SSRs showed 38–39% transferability, while among wild Cajanus species, it ranged from 26% in Cajanus sericeus ICP 15760 to 40% in C. sericeus ICP 15761. The transferable primers exhibited extensive polymorphism in Cajanus with an average number of 4.11 alleles per marker. High level of polymorphism exhibited by chickpea microsatellite markers in the present study indicates their usefulness in diversity analysis, mapping agronomically important traits and marker-assisted breeding in pigeonpea. [ABSTRACT FROM AUTHOR]

Poor soil fertility and erratic rains are major constraints to crop production in semi-arid environments. In the smallholder farming systems of sub-Saharan Africa, these constraints are manifested in frequent crop failures and endemic food insecurity. We characterized a semi-arid smallholder farming system in south-western Zimbabwe to assess crop production, nutrient use and factors that constrain productivity. The farming system was studied using resource flow mapping, farmer interviews and calculations of crop production over three cropping seasons (2002/2003, 2003/2004 and 2004/2005) to capture variability between years. Farmers were categorized into three groups: better resourced, medium resourced and poorly resourced. Better resourced farmers produced adequate grain for basic household consumption, except in the drought year (2002/2003). Poorly resourced farmers had large grain deficits, whereas the medium resourced class had smaller deficits. Better resourced and medium resourced farmers produced adequate amounts of staple cereal in two of the seasons, while poorly resourced farmers produced inadequate amounts of food in all three seasons. All farmers produced less than 300 kg/ha of legumes per season. Lack of seed was cited as the main reason for poor legume production. Better resourced farmers used animal manure (2000–5000 kg per season) and some fertilizer on their cereal crops, while the medium resourced group used less manure (1000 kg or less) and no fertilizer. The use of manure varied strongly across the years. Poorly resourced farmers used no nutrient inputs on any of their crops. All groups had negative nitrogen balances during the three cropping seasons, although the values varied strongly between seasons. Investigation of the potential strategies for developing sustainable production systems are required to address the problems of food security in the semi-arid parts of the country and the region. [ABSTRACT FROM AUTHOR]

Nodule numbers are regulated through systemic auto-regulatory signals produced by shoots and roots. The relative effects of shoot and root genotype on nodule numbers together with relationships to organ biomass, carbon (C) and nitrogen (N) status, and related parameters were measured in pea ( Pisum sativum) exploiting natural genetic variation in maturity and apparent nodulation intensity. Reciprocal grafting experiments between the early (Athos), intermediate (Phönix) and late (S00182) maturity phenotypes were performed and Pearson's correlation coefficients for the parameters were calculated. No significant correlations were found between shoot C/N ratios and plant morphology parameters, but the root C/N ratio showed a strong correlation with root fresh and dry weights as well as with shoot fresh weight with less significant interactions with leaf number. Hence, the root C/N ratio rather than shoot C/N had a predominant influence on plant morphology when pea plants are grown under conditions of symbiotic nitrogen supply. The only phenotypic characteristic that showed a statistically significant correlation with nodulation intensity was shoot length, which accounted for 68.5% of the variation. A strong linear relationship was demonstrated between shoot length and nodule numbers. Hence, pea nodule numbers are controlled by factors related to shoot extension, but not by shoot or root biomass accumulation, total C or total N. The relationship between shoot length and nodule numbers persisted under field conditions. These results suggest that stem height could be used as a breeding marker for the selection of pea cultivars with high nodule numbers and high seed N contents. [ABSTRACT FROM AUTHOR]

Characterization of 16 grasspea ( Lathyrus sativus L.) accessions collected in central Italy (Marche region) was performed for morphological and agronomic traits and for 3-(-N-oxalyl)-L-2,3 diaminopropionic acid (ODAP) content. Field trials, carried out in two locations, revealed high among-population genetic variation. In particular, an evident differentiation between commercial populations, cultivated by market-oriented farms, and household populations (not market-oriented) was found. Genotype × environment interaction was negligible. Medium–high values of ODAP content were observed following colorimetric and capillary electrophoresis analyses. A high positive correlation between the two methods was found (r = 0.83**), but the colorimetric values showed, on average, significant 14% lower ODAP values. This research represents a pre-breeding activity aimed at developing a breeding programme for the preservation and utilization of Italian grasspea germplasm within sustainable or organic agricultural systems. [ABSTRACT FROM AUTHOR]

In a crop rotation trial, conducted from 1985 to 1988 at TU-Munich's research station in Roggenstein, the transfer of grain legume nitrogen was evaluated in crop rotations containing fababeans and dry peas as well as oats (reference crop) and winter wheat and winter barley as following crops. The results obtained can be summarized as follows: Dinitrogen fixation by fababeans ranged from 163 to 240 kg N ha-1, whereas N2-fixation by peas amounted from 215 to 246 kg N ha-1. In all seasons the calculated N-balance where only grain was removed was positive, with a net gain being on average 106 (peas) and 84 (fababeans) kg N ha-1. After the harvest of peas 202 kg N ha-1 remained on the field on average over seasons (158 kg N ha-1 in the above ground biomass and 44 kg N ha-1 as NO3-N in 0-90 cm depth). As compared to peas, fababeans left 41 kg N ha-1 less due to smaller amounts of nitrogen in the straw. After oats very small amounts of residual nitrogen (33 kg N ha-1) were detected. After the harvest of grain legumes always a very high nitrogen mineralization was observed during autumn especially after peas due to a close C/N-relationship and higher amounts of nitrogen in the straw as compared to fababeans. In comparison with fababeans, N-minerahzation after the cultivation of oats remained lower by more than 50%. During winter, seepage water regularly led to a considerable decrease of soil NO3-N content. The N-leaching losses were especially high after cultivation of peas (80 kg N ha-1) and considerably lower after fababeans (50 kg N ha-1) and oats (20 kg N ha-1). As compared to oats, a higher NO3-N content in soil was determined at the beginning of the growing period after preceding grain legumes. Therefore, winter wheat yielded highest after preceding peas (68 dt ha-1) and fababeans (60 dt ha-1) and lowest after preceding oats (42 dt ha-1). The cultivation of grain legumes had no measurable effect on yield formation of the third crop winter barley in either of the growing seasons. [ABSTRACT FROM AUTHOR]

The growth of young plants of the epigeal species Phaseolus vulgaris and Glycine max is compared with that of the hypogeal species Pisum sativum and Vicia faba, with particular reference to synchronization between the exhaustion of seed reserves of N and the availability of fixed N. It is argued that the N stress symptoms which occur when these two processes are not synchronized are more common and obvious in Phaseolus or Glycine than in Pisum or Vicia. This is primarily because in these species (a) the first fixed N is used for nodule growth rather than being exported to the shoot system and (b) the first foliage leaves have a much greater area and contain a larger proportion of N reserves from the seed. It is further suggested that Phaseolus and Glycine may show the greater response to nitrogen fertilizer applied at sowing since (a) most of the applied nitrate is passed directly to the shoots (rather than being reduced in the roots as in Pisum or Vicia) and (b) in addition to being used for growth (following reduction), it may also be used prior to reduction as part of the osmotic force driving cell expansion. [ABSTRACT FROM AUTHOR]

The spatial and temporal relationships between carbon (C) metabolism and nitrogen (N) nutrition in grain legumes are of great academic interest with the added bonus that any data for economically important species may ultimately prove useful to breeders and growers. So far there are no data which can be used to relate differences in carbon usage by any symbiotic association with differences in economic yield. Much research has focussed on the dependence of dinitrogen fixation on photosynthate supply, on the C-N relationships of nodulated roots and nodules and on diurnal and seasonal profiles of dinitrogen fixation. In all these aspects a plethora of responses have been described, often based on insufficiently proven measurement techniques; consequently unequivocal conclusions cannot be drown. We know little about within-species differences due to cultivar, strain of Rhizobium or environment, or about the proportions of any heritable variations which might be sufficiently large to merit inclusion among the selection criteria of grain legume breeders. [ABSTRACT FROM AUTHOR]