Introduction Of Legumes Research Articles

Effect of Preceding Intercrops inBTCotton on The Productivity of Succeeding Wheat Crop and Total System Productivity

A field experiment was conducted to study the effect of different intercrops and row ratio on the growth, yield and quality of hybrid Bt cotton and effect of preceding intercrops in Bt cotton on the productivity of succeeding wheat crop and total system productivity. The results showed that different yield attributes, grain and straw yield of wheat were not significantly affected by different intercrops, though numerically higher wheat yield was obtained, where it was sown after legume intercrops viz. Bt cotton + cowpea fodder or Bt cotton + summer moong intercropping systems, as compared to that after sole Bt cotton and Bt cotton intercropped with other non legume intercrops viz. maize fodder, Bajra fodder and long melon etc. During 2010–11 crop season, all the intercropping systems except Bt cotton+ Bajra fodder-wheat and Bt cotton + long melon-wheat system recorded significantly higher total system productivity as compared to sole Bt cotton-wheat system. However, during 2011–12 crop season, intercropping systems like Bt cotton + maize fodder-wheat and Bt cotton + cowpea fodder-wheat system recorded significantly higher total system productivity as compared to sole Bt cotton-wheat system, Bt cotton + summer moong-wheat, Bt cotton + Bajra fodder-wheat and Bt cotton+ long melon-wheat systems. The land use efficiency in Bt cotton-wheat and Bt cotton based intercropping system-wheat varied from 93 to 96 percent as compared to 59–63 percent in sole crop-wheat based systems. With the introduction of legumes as sole or intercrop component, soil N status either improved or it remained same as initial status of the soil.

Grass–legume ratio can change soil carbon and nitrogen storage in a temperate steppe grassland

In grassland, introduction of legume potentially can play a significant role in increasing soil carbon (C) and nitrogen (N) storage through increasing biomass C input. It has been reported that grass–legume ratio (GLR) is important in assessing benefits of grass–legume mixtures, however, little is known about how GLR affects soil C and N storage. As an effort to understand the effects and mechanisms of GLR on soil carbon and nitrogen storage, biological nitrogen fixation (BNF) by legumes, and changes in C and N storage in plants and soil were examined under swards with different densities of grasses and legumes over 4 years in a temperate steppe grassland. Results showed that total N storage in 0–40 and overall 0–150cm soil depths varied as GLR changed, reaching peak values when the GLR was equivalent to 1:1. Increased relative legume abundance significantly enhanced soil C storage in both 0–40 and 0–150cm soil depths, which was primarily attributed to an increase of aboveground biomass C. Soil organic C and total N varied with GLR changes, leading to stoichiometric shifts in soil C:N ratios, possibly influencing soil C storage through changing plant community structure and soil biochemistry. It is suggested that introducing legumes in steppe grasslands with a GLR of 1:1 could increase resources use efficiency and improve the sustainability of the environment.

Optimization the Work of Soil for the Cultivation of Afila Peas in Turda Area

By applying minimum tillage system are reduced degradation by erosion, increase organic matter, it restores the soil structure and through the introduction of legumes in rotation ensure a higher nitrogen quantity to crops which are in rotation. Research conducted at SCDA Turda in 2014 following the behavior of four varieties of afila peas in two soil tillage system (classical-with mould plow and with minimum tillage-the chisel variant) and the effect of tillage on the momentary and accessible water reserve from the soil. In the minimum tillage system with chisel obtained a very significant difference of production compared to the classic system (88g/m2) at green peas, and if mature pea beans the difference of -27 kg/ha obtained in variant with chisel being insignificant. Through the application of the minimum tillage system at pea get an important economy of 28.4% in terms of fuel costs (337.2 ron/ha) compared to the classic tillage system application (471 ron/ha). For producing a 1 ton peas in classical system is necessary to 21.9 l/t fuel consumption and fuel costs of 131.6 ron/t, higher than minimum tillage system were fuel consumption are 15.8 l/t with fuel costs of 94.9 ron/t.

Benefits of the Symbiotic Association of Shrubby Legumes for the Rehabilitation of Degraded Soils under Mediterranean Climatic Conditions

AbstractSoil degradation limits the potential for the re‐establishment of native plants. Most land restoration practices typically concentrate on the recovery of soil physical properties and plant establishment, while neglecting the recovery of soil microbiota. Mediterranean wild leguminous shrubs are ideal candidates for use in land recovery projects, as they are drought tolerant, improve soil fertility through biological nitrogen fixation and exhibit high stem net photosynthesis that increases their carbon gain. In this study, we used the legumes Cytisus balansae, Cytisus multiflorus, Cytisus striatus and Genista florida in a long‐term trial to recover a degraded soil in southwestern Spain. The main objective of this trial was to investigate to what extent the introduction of shrubby legumes inoculated with their own rhizobial symbionts can improve the properties and associated vegetation of a degraded soil. The results showed that the inoculation of legumes with nitrogen‐fixing bacteria enhanced plant performance in all four legumes. Whereas in the absence of legumes, soil fertility and plant community did not improve significantly, amelioration was observed in plots with non‐inoculated legumes, with maximum values in terms of the number of accompanying species, soil nitrogen content and organic matter recorded in soils with inoculated legumes. Copyright © 2015 John Wiley & Sons, Ltd.

English

Integrated crop-livestock is advocated to be very promising in boosting food productivity and soil fertility in Nigeria owing to its numerous synergistic benefits as outlined in this review. Particularly, the system will be very suitable in the savannah regions of the country where livestock production is predominant. Although integrated crop-livestock farming has been in existence in these regions, it is typically cereal based-livestock system resulting in perennial depletion of soil fertility. Introduction of legumes into the system to form cereal-legume-livestock system can function as a key integrating factor through improvement of soil fertility, provision of healthy protein in the human diet and fodder for livestock consumption. This paper therefore, aimed to review the benefits of introduction of legumes like cowpea into the long existing cereal based livestock farming in Nigeria, particularly in the savannah regions of the country in order to boost food security and income of the farmers. The review showed that incorporation of cowpea into the system will in greater measure increase the overall food productivity, ensures sustainability of the soil fertility and substantially improves the income of the farmers in the country.   Key words: Cowpea fodder, soil fertility, food security, nutrient cycling.

Production improvement through phosphorus fertilization and legume introduction in grazed native pastures of Uruguay

SUMMARYThe objective of the current study was to quantify the response of pasture to phosphorus (P) fertilizer application and legume introduction, by measuring herbage yield, nitrogen (N) and P content, and weight gain of calves in native pastures of Uruguay. Quantitative relationships between pasture characteristics and post-weaning daily live weight gain (DLWG) were also examined. The treatments studied were native grassland (NG) and improved pasture, oversown withLotus corniculatusL. andTrifolium repensL. with annual applications of either 13 and 26 kg P/ha. From 1996 to 2001 the treatments were evaluated each year with a new group of calves. Total herbage yields of the oversown pastures were not always higher than NG in the initial years, but legume production increased, although without significant differences between P rates on legume or total yield. This was also reflected in the N and P status of the swards. In the last 2 years legume proportion had declined to <0·1, but total herbage yield was significantly higher in the improved pastures. The average DLWG over the 6 years of measurements were 0·319, 0·478 and 0·586 kg/day for NG, P1 and P2, respectively, with average total live weight gain increased 1·8- and 2·5-fold by the legume introduction and annual addition of 13 and 26 kg P/ha, respectively. The study demonstrated that the evaluation of pasture response to P application should not be limited to assessing forage yield increase. Phosphorus availability in the herbage was a better predictor of animal performance than pasture yield. The study highlights that the benefits of oversowing and fertilizer inputs are short-lived, as withholding of fertilizer in the last 2 years resulted in a loss of sown legumes and decline in animal production.

Legumes or nitrification inhibitors to reduce N2O emissions from subtropical cereal cropping systems in Oxisols?

The DAYCENT biogeochemical model was used to investigate how the use of fertilizers coated with nitrification inhibitors and the introduction of legumes in the crop rotation can affect subtropical cereal production and N2O emissions. The model was validated using comprehensive multi-seasonal, high-frequency dataset from two field investigations conducted on an Oxisol, which is the most common soil type in subtropical regions. Different N fertilizer rates were tested for each N management strategy and simulated under varying weather conditions. DAYCENT was able to reliably predict soil N dynamics, seasonal N2O emissions and crop production, although some discrepancies were observed in the treatments with low or no added N inputs and in the simulation of daily N2O fluxes. Simulations highlighted that the high clay content and the relatively low C levels of the Oxisol analyzed in this study limit the chances for significant amounts of N to be lost via deep leaching or denitrification. The application of urea coated with a nitrification inhibitor was the most effective strategy to minimize N2O emissions. This strategy however did not increase yields since the nitrification inhibitor did not substantially decrease overall N losses compared to conventional urea. Simulations indicated that replacing part of crop N requirements with N mineralized by legume residues is the most effective strategy to reduce N2O emissions and support cereal productivity. The results of this study show that legumes have significant potential to enhance the sustainable and profitable intensification of subtropical cereal cropping systems in Oxisols.

Grass-legume mixtures impact soil N, species recruitment, and productivity in temperate steppe grassland

In this study, we aimed to understand effects and mechanisms of legume species and their relative abundance on soil N, species recruitment, and productivity in mixed grassland. We also assessed the utilization prospect of several legumes in natural grassland. In 2006, grass-legume combinations (GLCs) with different ratios (GLR) were established using Leymus chinensis and four legume species (Medicago ruthenica, Lespedeza daurica, Medicago falcata, and Medicago sativa). In 2009, plant and soil samples were taken to examine the differences in soil nitrogen (N) properties, biological N fixation (BNF), recruitment characteristics, and aboveground biomass of the community under different mixture patterns. Soil total N and available N concentration increased when legume component increased from GLR 1:0 (grass monoculture) to GLR 1:1 (grass:legume 1:1) but decreased as legume component increased further from GLR 1:3 (grass:legume 1:3) to GLR 0:1 (legume monoculture). GLR 1:1 had the highest BNF in most GLCs except for L. chinensis-M. falcata. For any GLR with legume, L. chinensis-M. sativa combination (L-MS) had higher soil total N, available N, water content, and BNF. The legume combinations with a GLR lower than 1:1 resulted in more species recruitments compared with the grass monoculture, and L-MS induced relatively more species recruitments than other GLCs, which were correlated with improved soil water and NO3 −-N status. The grassland productivity increased as the GLR decreased; in any GLRs with legume, higher productivity was found under L-MS combination, and current results showed that grassland productivity was positively linked to soil NO3 −-N availability influenced by grass-legume mixture. We concluded that the species and relative abundance of legumes had great impact on soil N status, species recruitment, and productivity in this temperate grassland ecosystem. In this study site, legume introduction can be considered as an alternative to N fertilization for increasing grassland productivity. M. sativa has the greatest economic and ecological potential species to be mixed into natural temperate steppe grassland, and grass-legume ratio 1:1 is the best combination in mixed communities.

Factors affecting the recovery of abandoned semi-arid fields after legume introduction on the Loess Plateau

The Loess Plateau of China has suffered from soil erosion for several decades. As part of the Chinese “Grain for Green” project, legume species have been introduced to restore degraded ecosystems in this region. However, information on how environmental variables influence the recovery of vegetation after legume introduction is scarce. We characterized the composition of plant communities and different environmental variables 11 years after the introduction of the legumes Medicago sativa L. and Melilotus suaveolens L. in abandoned fields of the Loess Plateau. The objectives of this research were to evaluate how environmental factors such as duration of experiment, precipitation, soil moisture, soil nutrition, and topography affect the changes in plant species composition, richness and diversity and to identify the key factors driving plant species succession. Multivariate analyses were used to evaluate the relationships between plant communities and environmental variables. These analyses showed that plant species composition varied through time, with annual species being replaced by perennial herbaceous species gradually. The introduction of Medicago and Melilotus to abandoned fields had different effects on later-successional species and changed the successional trajectory of vegetation in the abandoned fields studied. Time since restoration was the most important factor influencing the composition of vegetation. Slope position, soil moisture content, annual precipitation, and slope/aspect were also key factors driving the composition of the plant community. Our results have implications for studies of secondary succession and the topographic and climatic impacts on vegetation change in restoration ecosystems of the semi-arid Loess Plateau, and emphasize the importance of plant–topography–climate interactions in defining the structure and composition of plant communities.

Designing eco-efficient crop rotations using life cycle assessment of crop combinations

Intensive arable crop production has major impacts on the environment and solutions for their reduction are needed. Diversification of crop rotations together with improved nitrogen management is an option for more eco-efficient cropping systems. The potentials for reducing the environmental impacts cropping systems were investigated by means of life cycle assessment (LCA) in three regions in France (Beauce, Burgundy and Moselle).The crop management data were compiled by the Chambers of Agriculture in the three regions based on field survey data (2002–2009 in Burgundy and Moselle and 2004–2008 in Beauce) and completed by experts. The LCA calculations were carried out by the SALCA-crop tool, using the ecoinvent and SALCA inventory databases and SALCA emission models. The LCAs were calculated for crop combinations, which were an efficient way to analyse a large number of crop rotations. A crop combination is defined as the inventory of a given crop, with a defined preceding crop and eventually including a catch crop.Nitrogen management revealed to be a key driver for the environmental impacts. It dominated the non-renewable energy demand, the global warming potential, the ozone formation potential, the acidification potential, and the eutrophication potential. Strong correlations between N fertilisation and these environmental impacts were found. The introduction of pea allowed to reduce the total eutrophication over the whole crop rotation. The mitigation of environmental impacts was not only possible per hectare, but also per € gross margin II. The eco-efficiency can thus be improved by reducing the level of N fertilisation. A reduction of N fertilisation could be achieved also by a reduction of the fertiliser doses to the non-legume crops, in addition to the introduction of legumes. Both ways proved to be effective and the combination of both was the most promising. However, trade-off between environmental and economic goals was identified.Diversification of cereal intensive crop rotations proved to be generally favourable from an environmental point of view. Catch crops had favourable effects on nutrient leaching a slightly favourable effects on biodiversity and soil quality. The ecotoxicity potentials were dominated by a few active ingredients only; the diversification did not lead to generally reduced ecotoxicity potentials.Diverse crop rotations with reduced N input are a promising way to reduce the environmental impacts of intensive arable crop rotations.

The impact of grassland management on biogeochemical cycles involving carbon, nitrogen and phosphorus

Grassland introduction into intensively managed agricultural landscapes may enhance soil organic matter (SOM) content and ecosystem services. However, the magnitude of this effect depends on grassland management practices, and their influence on the soil system. The aim of this paper is to highlight these impacts and their consequences for SOM dynamics and element cycling. We focused in particular on the effect of different grassland management practices in terms of grazing regime, fertilization, and species choice. While carbon, nitrogen and phosphorus cycles are more strongly coupled under grassland as compared to permanent cropping, uncoupling of elemental cycles may occur through management intensification. Grazing regime, fertilization and species choice affect elemental coupling and SOM turnover via organic matter input and rhizosphere activity to different extent, thereby resulting in contrasting SOM storage. Grazing may be more beneficial for SOM contents compared to mowing up to a certain animal density depending on soil type and pedoclimatic context. SOM storage may be increased in some cases through specific fertilizer additions, whereas in others no change was observed. Species choice, e.g. high diversity or introduction of legumes, influence element budgets and soil nutrient availability through plant physiological constraints as well as intra-or interspecific interactions. The effect of different plant species mixtures on soil parameters has rarely been elucidated. We conclude that the impact of grassland management practices on SOM of different soil types and the resulting ecosystem services, such as C and nutrient storage need further research in contrasting pedoclimatic contexts. More studies on the controls of belowground biogeochemical cycling of elements are necessary in order to fully understand and manage belowground processes via aboveground plant communities.

Mitigation of environmental impacts of beef cattle production in southern Brazil – Evaluation using farm-based life cycle assessment

Numerous mitigation strategies have been proposed in order to reduce environmental impacts from beef cattle production. In this sense, this study aimed to evaluate the effects of additive changes in the animal and pasture management of a beef cattle production system typical of south Brazil (baseline scenario – BS), in terms of climate change, land use and fossil depletion. These changes included: increasing the forage production; improving the forage quality; introducing legumes to replace nitrogen fertilization; improving the reproductive rates and; increasing the forage utilization efficiency. It was also considered the stabilization of the soil carbon (C) stocks in a long-term perspective. In BS was estimated, per kg of live weight gain, the greenhouse gas (GHG) emission of 22.5 kg of CO2 equivalents; the land use of 234.8 m2a and; 0.004 kg of oil equivalents in fossil depletion. Changes in forage production and quality resulted in GHG emissions equivalent to 7.8–20.7% of the BS and, to 0.5–1.2% of the BS with reproductive animal improvements. Land use reduces 9.4–30.6 times with these changes. The introduction of legumes to replace the nitrogen fertilizers engendered negative values of fossil depletion. The intensification of pasture utilization results in GHG emissions corresponding to 0.5% of the BS, and in a land use 32 times lower. Considering the long-term stabilization of soil C stocks, the systems that received nutritional and reproductive improvements presented reductions of GHG emissions from 2.5 to 3.2 times. A sensitivity analysis indicated the possibility of all short term improved scenarios become net sinks of C if gradual increments of root/shoot ratios in the range of values suggested by Intergovernmental Panel on Climate Change for Pampa Biome were applied. The scenarios confirm the hypothesis that productive improvements and environmental protection are not contradictory, and highlight the importance of biomass C dynamics and regional peculiarities in mitigation of environmental impacts from forage-livestock systems.

Breeding Annual Grain Legumes for Sustainable Agriculture: New Methods to Approach Complex Traits and Target New Cultivar Ideotypes

Although yield and total biomass produced by annual legumes remain major objectives for breeders, other issues such as environment-friendly, resource use efficiency including symbiotic performance, resilient production in the context of climate change, adaptation to sustainable cropping systems (reducing leaching, greenhouse gas emissions and pesticide residues), adaptation to diverse uses (seeds for feed, food, non-food, forage or green manure) and finally new ecological services such as pollinator protection, imply the need for definition of new ideotypes and development of innovative genotypes to enhance their commercialization. Taken as a whole, this means more complex and integrated objectives for breeders. Several illustrations will be given of breeding such complex traits for different annual legume species. Genetic diversity for root development and for the ability to establish efficient symbioses with rhizobia and mycorrhiza can contribute to better resource management (N, P, water). Shoot architectures and phenologies can contribute to yield and biotic constraint protection (parasitic weeds, diseases or insects) reducing pesticide use. Variable maturity periods and tolerance to biotic and abiotic stresses are key features for the introduction of annual legumes to low input cropping systems and for enlarging cultivated area. Adaptation to intercropping requires adapted genotypes. Improved health and nutritional value for humans are key objectives for developing new markets. Modifying product composition often requires the development of specific cultivars and sometimes the need to break negative genetic correlations with yield. A holistic approach in legume breeding is important for defining objectives with farmers, processors and consumers. The cultivar structures are likely to be more complex, combining genotypes, plant species and associated symbionts. New tools to build and evaluate them are important if legumes are to deliver their exciting potential in terms of agricultural productivity and sustainability as well as for feed and food.

Atributos químicos do solo, reservas orgânicas e sistema radicular de pastos degradados associada à introdução de leguminosa

The aim was to study the recovery of degraded pasture with the introduction of Stylosanthes macrocephala e capitata cv. Campo Grande on Brachiaria decumbens cv. Basilisk evaluating the levels N-total in roots, biomass, area, and length, diameter and root levels of macro and micronutrients in the soil. The experiment was conducted in the municipality of Andradina, Sao Paulo State, Brazil. The experimental design was a randomized block design in a split-plot (with and without phosphorus), with four replicates, forming the following treatments: control Brachiaria decumbens (CB), partial desiccation with 1.5 L ha-1 of glyphosate (DP), total desiccation with 3.0 L ha-1 of glyphosate (TD); tillage (T), soil scarification (S); harrowing rome (H) and plowing + disking (PD). Treatments H and PD were sown by broadcasting and the other in the form of direct seeding. Recovery strategies of grazing signal grass showed significant differences between treatments only for the content of N-total, there were no differences in geometric characteristics of roots and root biomass. The contents of macro and micronutrients in the soil showed no significant differences between the strategies of recovery. Fertilization had a significant effect for P. The introduction of estilosantes Campo Grande accompanied by techniques such as drying and plowing + disking contributed to increases in the N-total levels in the root system. Forms of introduction of legumes did not change the soil chemical properties.

Life cycle assessment of beef cattle production in two typical grassland systems of southern Brazil

The importance of animal production in the overall context of human activity is undisputed and influences food supply, job security, income producing, as well as landscape and local ecosystems conservation. This relevance enhances the charges by society as the environmental impacts of various activities, especially in relation to ruminant production amid the current problems of climate changes. In this context, we analyzed the main environmental impacts of two typical beef cattle production systems from southern Brazil, namely the extensive system (ES) and the improved system (IS), and identified the components that have the greatest environmental impacts using the life cycle assessment method. The basis of the system construction was a cattle herd that originated from 100 weaned heifers, four weaned calves, and the progeny of these cattle during their productive life (12 years), and the land areas, external inputs, and other natural resources and technologies necessary to the operations. The functional unit was the production of 1 kg of live weight. The values of greenhouse gas emissions, land use, and freshwater depletion in the ES were higher compared with those values obtained for the IS (22.52 and 9.16 kg CO2 equivalents; 234.78 and 21.03 m2a; and 0.217 and 0.0949 m3, respectively). These variations were attributed to the permanence time of the animals in each system and to the quality and production of the pastures. The ES presented lower potential impacts than the IS on metal depletion and soil acidification (0.000519 and 0.0536 kg Fe equivalents; and 0.0028 and 0.0038 kg SO2 equivalents, respectively) mainly due to the pasture improvement practices and the salt supply to the animals. Moreover, the values of freshwater eutrophication and fossil depletion were higher in the ES than in the IS (0.00383 and 0.00219 kg P equivalents and 0.0042 and −0.1255 kg oil equivalents, respectively). While the pasture nutrient loss from runoff and leaching defined the values of eutrophication, the introduction of legumes compensates the use of fossil fuels. The diversity of the results provides a better understanding of the environmental impacts of different production systems and of regional singularities.

Decomposition of cattle dung on mixed grass-legume pastures

Animal excreta contribute positively to nutrient cycling and can improve the quality of soil (Dubeux Jr. et al. 2009; Carvalho et al. 2010). Cattle excrement, when evenly distributed over a pasture, can help to maintain plant nutrition without the application of fertilizers. The introduction of legumes intercropped with grasses benefits the soil by means of nitrogen fixation. When ruminant animals eat legumes, the feces produced may have lower C:N, C:P, lignin:N and lignin:P ratios, promoting better nutrient return to the soil than when cattle eat only grass. Given the importance of nutrient return from and decomposition time of cattle feces on pastures, the objective of this study was to quantify the decomposition of feces of heifers managed in mixed grassshrubby legume pastures and grass-only pastures.

Turnover of organic carbon and nitrogen in soil assessed from δ13C and δ15N changes under pasture and cropping practices and estimates of greenhouse gas emissions

The continuing clearance of native vegetation for pasture, and especially cropping, is a concern due to declines in soil organic C (SOC) and N, deteriorating soil health, and adverse environment impact such as increased emissions of major greenhouse gases (CO2, N2O and CH4). There is a need to quantify the rates of SOC and N budget changes, and the impact on greenhouse gas emissions from land use change in semi-arid subtropical regions where such data are scarce, so as to assist in developing appropriate management practices. We quantified the turnover rate of SOC from changes in δ13C following the conversion of C3 native vegetation to C4 perennial pasture and mixed C3/C4 cereal cropping (wheat/sorghum), as well as δ15N changes following the conversion of legume native vegetation to non-legume systems over 23years. Perennial pasture (Cenchrus ciliaris cv. Biloela) maintained SOC but lost total N by more than 20% in the top 0–0.3m depth of soil, resulting in reduced animal productivity from the grazed pasture. Annual cropping depleted both SOC and total soil N by 34% and 38%, respectively, and resulted in decreasing cereal crop yields. Most of these losses of SOC and total N occurred from the >250μm fraction of soil. Moreover, this fraction had almost a magnitude higher turnover rates than the 250–53μm and <53μm fractions. Loss of SOC during the cropping period contributed two-orders of magnitude more CO2-e to the atmosphere than the pasture system. Even then, the pasture system is not considered as a benchmark of agricultural sustainability because of its decreasing productivity in this semi-arid subtropical environment. Introduction of legumes (for N2 fixation) into perennial pastures may arrest the productivity decline of this system. Restoration of SOC in the cropped system will require land use change to perennial ecosystems such as legume–grass pastures or native vegetation.

Recovery of Soil C and N in a Tropical Pasture: Passive and Active Restoration

AbstractSoil degradation by deforestation and introduction of exotic grasses is a grave consequence of land‐use change in tropical regions during the last decades. Soil restoration following natural succession (i.e., passive restoration) is slow because of low tree establishment. Introduction of tree plantings by human intervention (i.e., active restoration) results in a promising strategy to accelerate forest succession and soil recovery in tropical region. The present research was carried out to explore the restoration of soil properties after cattle exclusion and of grazing combined with native tree planting introduction (legumes and nonlegumes) in a tropical pasture in Veracruz, southeast Mexico. Results indicate that land‐use changes decreased soil C and N pools in both litter and mineral soil. In addition, soil heterogeneity increased by land‐use changes at both temporal and spatial scales. In the short term, passive succession (i.e., cattle exclusion) favors the recovery of C and N content in labile soil pools, indicated by the increase in litter C and N masses as well as C and N concentrations in soil microbial biomass. Soils under active restoration showed trends to recover the N cycling, such as a greater accumulation of N in litter, in soil total N concentrations, soil microbial biomass N concentrations, rates of net N transformations, and extractable water and microbial biomass C:N ratios mainly under legumes species. Active restoration including legume introduction is a key factor for rapid recovery of soil fertility. Copyright © 2013 John Wiley &amp; Sons, Ltd.

Status of animal feed resources in Rwanda

Animal feed resources remain a major constraint for livestock development in tropical Africa. In Rwanda, grazing lands are shrinking sharply because crop cultivation is progressively encroaching on grazing areas with increasing human pressure (Mutimura and Everson 2011). Therefore, over 60% of households cultivating less than 0.7 ha, and owning livestock, practize zerograzing, where farmers cut-and-carry forage and crop residues to feed animals that are kept exclusively under sheds (MINAGRI 2009). In general, the main feed for dairy cattle under a zero-grazing system is Napier grass (Pennisetum purpureum). For more than a decade, efforts to improve the feed resource base and feeding management have been based on the introduction, characterization and evaluation of exotic forage species, including grasses and legumes. The main aim of this study was to identify and document the status of improved forages as animal feed resources and for use in environmental protection in Rwanda.

Cross‐allergic Reactions to Legumes in Lupin and Fenugreek‐Sensitized Mice

Several legumes may induce allergy, and there is extensive serological cross-reactivity among legumes. This cross-reactivity has traditionally been regarded to have limited clinical relevance. However, the introduction of novel legumes to Western countries may have changed this pattern, and in some studies cross-allergy to lupin has been reported in more than 60% of peanut-allergic patients. We wanted to explore cross-reactions among legumes using two newly established mouse models of food allergy. Mice were immunized perorally with fenugreek or lupin with cholera toxin as adjuvant. The mice were challenged with high doses of fenugreek, lupin, peanut or soy, and signs of anaphylactic reactions were observed. Cross-allergic mechanisms were investigated using serum mouse mast cell protease-1 (MMCP-1), antibody responses, immunoblotting and ex vivo production of cytokines by spleen cells. Signs of cross-allergy were observed for all the tested legumes in both models. The cross-allergic symptoms were milder and affected fewer mice than the primary allergic responses. The cross-allergy was reflected to a certain extent in the antibody and T-cell responses, but not in serum MMCP-1 levels. Cross-allergy to peanut, soy, fenugreek and lupin was observed in lupin-sensitized and fenugreek-sensitized mice. Differences in serological responses between primary allergy and cross-allergy might be due to mediation through different immune mechanisms or reflect different epitope affinity to IgE. These differences need to be further investigated.