Integration Of Legumes Research Articles

Urochloa Grasses Swap Nitrogen Source When Grown in Association with Legumes in Tropical Pastures

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.

Simulating medium-term effects of cropping system diversification on soil fertility and crop productivity in southern Africa

Diversification of cropping is perceived as a strategy to simultaneously achieve high productivity and maintain environmental sustainability. In southern Africa, however, due to a lack of medium to long-term field trials, there is missing quantitative information. Utilising the capability of agro-ecosystem models to quantify the interactions of crop productivity with management and environmental variables, the APSIM model was evaluated against six and an eight-year field trial datasets comprised of different crop rotations and fertiliser rates under two contrasting agro-ecological conditions in South Africa (clay soil with a mean rainfall of 871 mm versus a sandy soil with a 570 mm rainfall). Model output was compared to observed grain yield, aboveground dry matter, soil organic carbon (SOC), and mineral nitrogen (Nmin) dynamics. APSIM was able to reproduce the observed grain yield dynamics fairly well as indicated by a Wilmott index of agreement of 0.90. Prediction accuracy, as indicated by the absolute model error across all crops, however, only reached 39%. Simulated Nmin and SOC dynamics showed similar patterns to the observations. Subsequently, the model was applied in a ten-year simulation experiment with rotation treatments (14 rotations, respectively intercropping systems, including a maize monoculture control), fertiliser levels (zero and 70 kg N ha−1), and residue management (retained and removed) for the two sites. For low input systems, such as smallholder farms, residue management and legume integration are of the utmost importance to maintain SOC and more pronounced Nmin levels, which, for the sandy soil, resulted in an average maize yield increase of up to 1000 kg ha−1. Maize monoculture treatments with residues removed reduced SOC moderately by 0.04–0.08 %, while yields declined strongly (>1000 kg ha−1) over the simulated period of ten years. In commercial, fertilised cropping systems, allocating land to cultivate crops other than maize reduced the simulated total yield performance. This diversification disadvantage has to be considered against the benefits of increased SOC and yields in the medium-term, i.e. a period of ten years. For the commercial systems, maize intercropped with delayed sown oats or cowpea appeared promising.

COMPLEMENTARY EFFECTS OF LEGUME INTEGRATION AND FERTILIZER APPLICATION ON SOIL MOISTURE AND LONG-TERM CARBON STOCKS IN MAIZE SYSTEMS OF KABETE SUB-COUNTY, KENYA

<p><strong>Background.</strong> Despite their immense benefits to smallholder farmers, the complementary effects of combined fertilizer sources with integration of legumes on soil moisture, soil organic carbon content, carbon stocks and their long-term projections in maize systems of Kabete sub-County, Kenya has not been fully investigated. This study will thus develop and promote a site specific technological package that will enhance maize productivity, resilience and sustainability of the smallholder farming systems. <strong>Objective</strong>. To determine the complementary effects of legume integration and fertilizer application on soil moisture and soil carbon stocks, and carbon stock changes over a 20-year period in maize systems of Kabete sub-County, Kenya. <strong>Methodology.</strong> The experiment was conducted at Upper Kabete field Research Station of the University of Nairobi during the long (LRS) and short (SRS) rainy seasons of 2015/2016. The experimental design was a Randomized Complete Block Design with a split plot arrangement. The main plots were integration of dolichos into maize (Z<em>ea mays L.</em>) systems; (i) as an intercrop (dolichos - <em>Lablab purpureus </em>(L.)/maize) and (ii) in rotation (dolichos-maize), and (iii) sole maize (without dolichos integration). The sub plots were organic and inorganic fertilizers: (i) Farmyard Manure (FYM), (ii) Triple Superphosphate (TSP)+Urea, (iii) FYM+TSP+Urea and (iv) no fertilizer input (control). Soil samples were collected at the end of each cropping season from 0-20 cm depth for determination of; soil moisture (%), soil organic carbon (SOC) content (%), and SOC stocks (t C ha<sup>-1</sup>). The Rothamsted Carbon model (Roth-C) was used to estimate carbon stock changes over a 20-year period with 1990 as the base year. <strong>Results.</strong> Significantly (P ≤ 0.05) high levels of soil moisture (31 and 30.1%) and SOC (2.6 and 2.5%) were respectively obtained in maize/dolichos intercrop with application of FYM and FYM+TSP+Urea during the SRS. The same trend in soil moisture and SOC was observed in the LRS. Significantly (P ≤ 0.05) high SOC stocks (t C ha<sup>-1</sup>) were obtained in maize/dolichos intercrop with FYM (56.20 and 54.71) and TSP+FYM+Urea (54.84 and 52.91) application in the SRS and LRS, respectively.<span style="text-decoration: line-through;"> </span>Over a 20-year period, SOC stocks maintained a significant and steady increase and were higher in maize/dolichos intercrop with FYM and FYM+TSP+urea application. The same pattern was noted in dolichos-maize rotation and sole maize systems. <strong>Implications.</strong> Given the importance of SOC in the improvement of soil quality, incorporation of legumes into maize systems with application of FYM is thus a plausible technological package that could enhance soil fertility and consequently food and nutritional security among smallholder farmers, not only of Kabete sub-County but Kenya and other countries. <strong>Conclusion.</strong> Significant increases in soil moisture content, organic carbon and, carbon stocks and their projections over a 20-year period were evident in maize/dolichos intercrop with FYM and TSP+FYM+Urea application in both seasons.</p>

Low seasonal nitrous oxide emissions in tea tree farming systems following nitrogen fertilisation using poultry litter application or green manure legumes

The integration of legumes into coppiced tree crop systems to replace some or all of the external nitrogen (N) fertiliser requirements may be one means to lower seasonal nitrous oxide (N2O) emissions. We investigated soil N2O emissions using static chamber methodology in field trials located within two commercial tea tree (Melaleuca alternifolia) plantations (Casino and Tweed Heads) where N (116 and 132 kg N ha–1 respectively) was supplied via poultry litter application (5 t wet ha–1) or by termination of annual legumes (soybean or mung bean) grown in the inter-row. While there was no treatment effect at the Tweed Heads site, both legume treatments had significantly (P = 0.01) lower cumulative N2O emissions (0.33 and 0.30 kg N2O-N ha–1 season–1 for soybean and mung beans respectively) than the poultry litter treatment (0.66 kg N2O-N ha–1 season–1) at the Casino site. However, the amount of N added to soils in each treatment was not identical owing to an inability to accurately predict N inputs by legume crops, and thus differences could not be attributed to the N source. A third site was thus established at Leeville comparing N2O emissions from poultry litter amendment (5 t wet ha–1 contributing 161 kg N ha–1) to an inter-row faba bean crop (contributing 92 kg N ha–1) and a nil-N control. Cumulative seasonal N2O emissions were significantly (P < 0.05) lower in the faba bean treatment than the poultry litter treatment (0.08 and 0.23 kg N2O-N ha–1 season–1 respectively), but owing to different N inputs and generally low emissions, it was not possible to draw definitive conclusions on whether green manure legume crops can lower N2O emissions. Overall, soil N2O emissions in coppiced tea tree systems under current management practices were very low, offering limited potential to reduce seasonal N2O emissions through management practice change.

Using a Participatory Approach and Legume Integration to Increase the Productivity of Early Maturing Maize in the Nigerian Sudan Savannas

Drought, infestation of cereal crops by the parasitic weed Striga hermonthica, and poor soil fertility are the major constraints to maize production by smallholder farmers in the Sudan savannas of northern Nigeria. Four innovation platforms (IPs) were therefore established in 2008 in the Sudan savanna (SS) agroecological zone of northern Nigeria to create a stakeholder forum to address these identified food production challenges in the target areas. The IPs comprised researchers from Bayero University, Kano; Institute for Agricultural Research, Zaria; International Institute of Tropical Agriculture; state and local government extension programs in Kano and Katsina states; input and output dealers; community-based organisations; and media organisations in the two states. The current study reports on the effects of legume integration on maize performance in farmer fields and the adoption of Striga management technologies introduced in the IPs over a four-year period. The deployment of drought- Striga-tolerant and early-maturing maize varieties along with legume rotation reduced Striga infestation by 46–100% when cowpea was rotated with maize, 80–97% when groundnut was rotated with maize, and 59–94% when soybean was rotated with maize. Grain yield of maize increased by 63–88% when cowpea was rotated with maize, 69–128% when groundnut was rotated with maize, and 9–133% when soybean was rotated with maize. Participatory and detailed questionnaire-based adoption surveys showed high adoption of improved maize varieties, five years after program interventions. The maize variety 99EVDT-W-STR C0 was the most popular among all the IPs because it is early maturing, Striga-resistant, and drought-tolerant. The high maize yields and high adoption rates suggest that the IP approach was effective in disseminating maize technologies.

Barriers to Agro-Ecological Intensification of Smallholder Upland Farming Systems in Lao PDR

Intercropping of legumes can be a strategy to improve soil fertility and enhance overall productivity while reducing dependency on external inputs in intensified cropping systems. Integration of legumes in maize-based cropping systems is promoted as an agro-ecological intensification option for input-constrained smallholders in uplands of Southeast Asia, but adoption rates in the region remain low. The overall aim of this study was to assess the suitability and trade-offs of integrating ricebean in maize-based smallholder cropping systems in upland areas of Northern Laos. We conducted a researcher-managed field trial to investigate the agronomic performance of ricebean/maize intercropping, and farmer-managed trials combined with surveys (N = 97), and focus group discussions in 10 villages to understand factors influencing farmers’ decision making concerning ricebean adoption. Drought, rat infestation and crop damage by grazing livestock were identified as important constraints to the production of ricebeans. Factors facilitating adoption included improvement of soil fertility, the potentially high selling price of ricebeans and the presence of extension agents, while barriers included labour shortage, concerns about competition with maize and lack of a market outlet for the ricebean produce. We conclude that the investigated maize/ricebean intercropping system is poorly suited to the current conditions in the study area, and call for farm-based studies focusing on developing locally adapted legume intercropping systems able to perform under variable rainfall conditions. Initiatives addressing challenges related to free grazing livestock and efforts to link legume producers in remote areas to emerging markets are also needed.

Effect of Applying Organic Amendments and Chickpea Integration on Soil Chemical Properties in Different Cropping Systems in Central Kenya

A study was carried out to determine the effect of applying farm yard manure (FYM) and Minjingu rock phosphate (MRP) on soil available nitrogen, phosphorus and organic carbon. The study involved field experiments under varying precipitation pattern, soil fertility levels and cropping systems over four growth seasons. The experimental design was a randomized complete block (RCBD) with four replications in a split plot arrangement where the main plots were the three cropping systems; monocropping, intercropping and crop rotation and the split plots were FYM and MRP and sampling done at crop physiological maturity. Soil pH, N, P K and C increased in the different treatments in the following order control < MRP < FYM in the three cropping systems across the four growing seasons at both sites. In maize under rotation with chickpea control had; 0.281% N, 2.82% C and 10.68 ppm P. FYM; 0.554% N, 4.41% C and18.24 ppm P. MRP; 0.45% N, 3.6% C and 41.08 ppm P. Maize chickpea intercrop control; 0.389% N, 3.192% C and 13.4 ppm P. FYM; 0.531% N, 4.98% C and 41.02 ppm P. MRP; 0.49% N, 4.08% C and 50.9 ppm P. Soil under maize monocrop exhibited; control; 0.2% N, 2.59% C and11.26 ppm P. FYM; 0.416% N, 3.83% C and 18.01 ppm P. MRP; 0.28% N, 3.13% C and 26.1ppm P. Almost a similar trend was observed in maize and tomato plots at both sites in all the growing seasons. Thus it can be deduced that, FYM and MRP application and legume integration in cropping systems improves soil fertility.

Intercropping of maize, millet, mustard, wheat and ginger increased land productivity and potential economic returns for smallholder terrace farmers in Nepal

Low nitrogen inputs, low crop yield, and low land productivity are major challenges associated with cereal-based sole cropping systems in Nepal. Crop intensification and diversification by introducing legumes as intercrops could help alleviate these challenges. With the presence of diverse crops and cropping systems, particularly in hilly topographies, a range of intercrop options is required. We compared 10 intercrop combinations to native sole cropping systems in the mid-hills of Nepal for two cropping seasons (2015–2017) to identify the most productive and economic intercrop combinations for smallholder terrace agriculture. In the spring-summer season (i.e., mid-March to mid-July), cowpea (var. Makaibodi and Suryabodi) and bean were intercropped with maize in 1:1 rows, whereas soybean, blackgram, and horsegram were broadcast with millet (30:70 ratios) during the rainy-autumn season (i.e., mid-July to mid-November). Pea and lentil were used as pre-winter/winter intercrops (i.e., mid-November to mid-March) in mustard (30:70 ratios), while wheat was planted with pea. Ginger was planted with maize in 1:1 rows during the spring-summer season in which the maize rows were replaced by soybean and lentil during the rainy-autumn and pre-winter/winter season, respectively. Plots were analyzed for yields of individual crops as well as other agronomic indicators including land equivalent ratio (LER), total land output (TLO), harvest index (HI), and potential economic return.Maize + cowpea var. Makaibodi appeared to be the most productive and economic intercrop combination for the spring-summer season (LER – 1.58 and TLO – 4.26 t ha−1, 21% higher than the maize sole crop with an increase in potential economic return by 67%) whereas millet + soybean appeared to be the best combination for the rainy-autumn season (LER – 1.40 and TLO – 2.21 t ha−1, 26% higher than the millet sole crop with a 288% increase in potential income). For the pre-winter/winter season, wheat + pea and mustard + pea combinations appeared to be productive (wheat + pea: LER – 1.31 and TLO – 2.90 t ha-1 i.e., 16% higher than sole wheat with a 54% increase in potential income; mustard + pea: LER – 1.36 and TLO – 2.14 t ha−1 i.e., 30% higher than sole mustard with a 15% increase in potential income). The year round intercrop system (i.e., ginger + maize-soybean) displayed a LER value of 2.45 with increased TLO (21.8 t ha−1 i.e., 2% higher compared to sole ginger) which increased potential economic return by 6%. We conclude that legume intercropping was a robust option across seasons and locations confirming that it could be a promising ecological practice for intensification of cereal-based sole cropping systems on smallholder terraces. Also, it is important to note that soybean and pea provided higher potential net income to farmers as sole crops compared to when they were grown with millet and wheat as intercrops, respectively. It is important that we promote these options to smallholder farmers and disseminate the advantages of legume integration on land productivity, soil fertility management, and income.

Sustainable intensification influences soil quality, biota, and productivity in cereal-based agroecosystems

Monotonous rice-wheat cropping system with conventional management practices have resulted in declining soil quality and biota in addition to low input factor productivity and farmer’s profitability in western Indo-Gangetic plains (IGP) of India. Conservation agriculture (CA) based sustainable intensification (SI) is required to improve the soil quality while improving the productivity and profitability. A field experiment was conducted to evaluate the effects of CA based management practices such as zero tillage (ZT), direct seeding of rice (DSR), crop diversification, residue recycling and legume integration for SI in comparison to conventional management on soil quality and biota in cereal (rice and maize) based cropping systems. Fourteen treatments were included in which four treatments (T1–T4) with rice–wheat and two treatments (T11–T12) with maize-wheat system were based on conventional management, while six treatments (T5–T10) with rice–wheat and two (T13–T14) with maize-wheat were based on CA management practices. Conservation agriculture based SI of maize-wheat-mungbean (T14) recorded lower soil bulk density (1.33 Mg m−3). Soil organic carbon (OC) was increased by 83% and 72% with CA based rice-wheat-mungbean (T10) and maize-wheat-mungbean (T14) system, respectively and it was at par with T9 and T12 compared to farmer’s practice (T1) (4.6 g kg−1). Mean microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) were 213% and 293% higher with T14 over T1 (646 and 201 µg g−1 dry soil), respectively. However, T10 recorded 117% and 171% higher MBC and MBN, respectively compared to T1. Dehydrogenase activity (DHA) and alkaline phosphatase activity (APA) were improved by 210% and 49% under T14; 140% and 42% under T10 compared to T1 (180 µg TPF g−1 soil 24 h−1 and 144 µg p-nitrophenol g−1h−1), respectively. Mean number of bacteria, fungi and actinomycetes were increased by 28%, 68%, 98% respectively, under T14 relative to T1, and at par with T12 and T10. Most abundant micro-arthropod group belonged to Collembola followed by Acari and Protura, irrespective of treatments. Higher soil quality index (SQI) was observed in T10 (0.82), followed by T14 and T6 treatment (0.76). Sustainable intensification of rice and maize based systems (T10 and T14) recorded 39% higher system yield compared to T1 (11.12 Mg ha−1). CA-based sustainable intensification of rice/maize systems improved soil quality and biota, hence resulted higher system yield in alluvial soils of IGP. Conservation agriculture based SI of maize-wheat-mungbean system was found to be the best alternative option than rice–wheat system to achieve sustainable productivity while improving the soil quality index (35%) and conservation of natural resources.

Maize yield and profitability tradeoffs with social, human and environmental performance: Is sustainable intensification feasible?

Sustainable intensification (SI) has been regarded as the basis for environmentally sound and equitable agricultural development. Field based assessment of technologies needs to move beyond production and economic performance to include environment, social and human condition. In this study we systematically consider all five domains of SI based on participatory action research (PAR) initiated in 2012 at three Central Malawi sites that varied in agroecology from low to high potential. Fifteen SI indicators were assessed for four technologies: sole maize (Zea mays L.) with 0 and recommended fertilization (69kg Nha−1 and 9kgPha−1), pigeonpea (Cajanus Cajun (L.) Millsp.)-maize intercrop (half rate fertilizer), and doubled up legume rotation (DLR, a pigeonpea-groundnut intercrop) sequenced with maize at half rate fertilizer in that phase. Through radar charts SI performance and tradeoffs were visualized, and causal loop analysis allowed identification of research gaps. SI indicator assessments included crop performance from on-farm trials, profitability, modeled probability of food sufficiency, risk of crop failure and ratings of technologies by women farmers who were engaged in evaluation of technologies through participatory research. The PAR included six mother trials, 236 baby trial farmers and a survey that was carried out with 324 farmers (baby trial farmers plus control farmers) to document socio-economic factors and management practices on focal fields. Replicated mother trials further provided the basis for simulation modeling (APSIM) of weather-associated crop failure risk and slow processes such as soil carbon (C) accrual. Radar charts were used to visualize SI performance of the technologies. Environmental performance of the two pigeonpea-diversified technologies was variable, but generally high compared with sole maize systems, due to gains in vegetative biomass, duration of cover and biological nitrogen (N) fixation. Maize production and economic assessment varied by site, and with steeper tradeoffs for legume diversification in the mesic site, less so in the marginal site. The domains of social and human capacity building were superior for legume integration, notably in terms of diverse diet, food security and farmer preferences (notably, female farmers generally favored legume crops). Performance varied by site with legume systems most beneficial at the most marginal site, including less risk of crop failure than unfertilized maize. Causal loop analyses identified regulators of SI that require further attention, notably: crop-livestock conflicts and opportunities, male-female control of legume crop production, and residue management. Overall, the SI indicators framework provided a systematic means to consider tradeoffs and opportunities associated with novel crop combinations and management practices.

Effect of Legume Integration and Phosphorus Use on Maize N and P Concentration and Grain Yield in Kabete - Kenya

Effect of Legume Integration and Phosphorus Use on Maize N and P Concentration and Grain Yield in Kabete - Kenya

Preferences for legume attributes in maize-legume cropping systems in Malawi

Adoption rates of leguminous crops remain low in sub-Saharan Africa despite their potential role in improving nutrition, soil health, and food security. In this study we explored Malawian farmers’ perceptions of various legume attributes and assessed how these perceptions affected allocation of land to legume crops using a logit link model. We found high regional variation in both consumption- and production-related preferences, but relatively consistent preferences across samples. While scientific understanding and farmer perceptions were aligned on some topics and for some legumes, there were discrepancies elsewhere, particularly in terms of soil fertility and nutrition. Understanding why these discrepancies exist and where there were potential biases are critical in explaining the extent of adoption. In many cases perceptions of legume attributes may be influenced by the cultural role of the crop in the household, particularly in terms of food security or market-orientation. The findings also suggest that researchers need to look beyond both the agronomic properties and farmers’ preferences to fully understand the extent of adoption. Socioeconomic factors, biases, and marketing concerns may also influence integration of legumes into maize-based cropping systems.

Characterization of Small-scale Farming Systems in West Kenya and Opportunities for Their Improvement

Designing agricultural transformation strategies that modernize small-scale farming in Africa require actions built upon solid, holistic baselines and proven, affordable technical intervention. A study was conducted in west Kenya to characterize the farming operations and household condition among smallhold farmers. The assessment consisted of a structured survey among 291 randomly selected households and compiled onto a single spreadsheet with rows as household cases and 98 descriptors as columns. Overall summary statistics were calculated, and then stratified by three criteria; household resource endowment, agro-ecological zone and sex of household head. A farming systems diagram was inferred from these results. Overall average farm size is 0.87 ha, family size is 6.8 persons and majorities of those interviewed were household heads (68% of respondents) and women (58% of respondents). A simple parameter of resource endowment describes weighted per capita field area per household member of about 1800m2. Household income is $466 per year, food shortfalls last 110 days per year, and households produce 819 kg cereals, 211 kg grain legumes and 74 kg root crops per year. These households raised 2.5 cattle, 1.4 goats or sheep and 13 chickens, deriving annual incomes of $78 from animal enterprise. The 39% of households with lowest resource endowment (< 1000m2 per capita) operate on only 0.34 ha per farm, earn only $155 per year, suffer food shortfalls of 122 days per year, and households produce 326 kg cereals and 119 kg grain legumes. Of the three agro-ecological zones within the study area, the Midlands offers the greatest opportunity for interventions as the Lake Victoria Basin is drier and the Upper Midlands is becoming peri-urban. Large contrasts were observed between women- and men-led households, with the former on farms 0.4 ha smaller, annual income $168 less, 18 additional days of hunger per year and producing 248 kg less cereals and 94 kg less grain legumes. Organic resource availability was approximately 3.3 tons per year and allocated in a variety of ways, with women allocating three-fold more manure to grain legumes, and most palatable crop residues being passed through livestock. These findings compare favorably to the four key entry points independently identified by the Humidtropics Program for its West Kenya Action Site; Legume Integration, Striga Elimination, Crop Diversity and Animal Enterprise, and interactions between these entry points offer promising lines to farming systems research in the future.

Characterising the diversity of smallholder farming systems and their constraints and opportunities for innovation: A case study from the Northern Region, Ghana

Typologies may be used as tools for dealing with farming system heterogeneity. This is achieved by classifying farms into groups that have common characteristics, i.e. farm types, which can support the implementation of a more tailored approach to agricultural development. This article explored patterns of farming system diversity through the classification of 70 smallholder farm households in two districts (Savelugu-Nanton and Tolon-Kumbungu) of Ghana⿿s Northern Region. Based on 2013 survey data, the typology was constructed using the multivariate statistical techniques of principal component analysis and cluster analysis. Results proposed six farm types, stratified on the basis of household, labour, land use, livestock and income variables, explaining the structural and functional differences between farming systems. Types 1 and 2 were characterized by relatively high levels of resource endowment and oriented towards non-farm activities and crop sales respectively. Types 3 and 4 were moderately resource-endowed with income derived primarily from on-farm activities. Types 5 and 6 were resource constrained, with production oriented towards subsistence. The most salient differences among farm types concerned herd size (largest for Type 1), degree of legume integration (largest for Types 2⿿4), household size and hired labour (smallest household size for Types 4 and 6, and largest proportion of hired labour for Type 4), degree of diversification into off/non-farm activities (highest for Type 1 and lowest for Type 5) and severity of resource constraints (Type 6 was most constrained with a small farm area and herd comprised mainly of poultry). It was found that livelihood strategies reflected the distinctive characteristics of farm households; with poorly-endowed types restricted to a ⿿survival strategy⿿ and more affluent types free to pursue a ⿿development strategy⿿. This study clearly demonstrates that using the established typology as a practical framework allows identification of type-specific farm household opportunities and constraints for the targeting of agricultural interventions and innovations, which will be further analysed in the research-for-development project. We conclude that a more flexible approach to typology construction, for example through the incorporation of farmer perspectives, might provide further context and insight into the causes, consequences and negotiation of farm diversity.

Trade-Offs between Economic and Environmental Impacts of Introducing Legumes into Cropping Systems.

Europe's agriculture is highly specialized, dependent on external inputs and responsible for negative environmental impacts. Legume crops are grown on less than 2% of the arable land and more than 70% of the demand for protein feed supplement is imported from overseas. The integration of legumes into cropping systems has the potential to contribute to the transition to a more resource-efficient agriculture and reduce the current protein deficit. Legume crops influence the production of other crops in the rotation making it difficult to evaluate the overall agronomic effects of legumes in cropping systems. A novel assessment framework was developed and applied in five case study regions across Europe with the objective of evaluating trade-offs between economic and environmental effects of integrating legumes into cropping systems. Legumes resulted in positive and negative impacts when integrated into various cropping systems across the case studies. On average, cropping systems with legumes reduced nitrous oxide emissions by 18 and 33% and N fertilizer use by 24 and 38% in arable and forage systems, respectively, compared to systems without legumes. Nitrate leaching was similar with and without legumes in arable systems and reduced by 22% in forage systems. However, grain legumes reduced gross margins in 3 of 5 regions. Forage legumes increased gross margins in 3 of 3 regions. Among the cropping systems with legumes, systems could be identified that had both relatively high economic returns and positive environmental impacts. Thus, increasing the cultivation of legumes could lead to economic competitive cropping systems and positive environmental impacts, but achieving this aim requires the development of novel management strategies informed by the involvement of advisors and farmers.

Doubled-up legume rotations improve soil fertility and maintain productivity under variable conditions in maize-based cropping systems in Malawi

Smallholder farmers in Malawi must cope with small farm size, low soil fertility and production risks associated with rainfed agriculture. Integration of legumes into maize-based cropping systems is advocated as a means to increase production of diverse nutrient-dense grains and improve soil fertility. It is difficult to achieve both aims simultaneously, however. Short-duration grain legumes rarely produce enough biomass to appreciatively improve soils, and long duration pigeonpea, commonly grown in Malawi as a dual purpose crop, produces little or no edible grain as a consequence of grain-filling into the dry season. A novel technology is the doubled-up legume rotation (DLR) system in which two legumes with complementary phenology are intercropped and grown in rotation with maize. Initial performance from on-farm research is favorable; however, it is crucial to understand competition for resources in mixed cropping systems under variable soil and climate conditions. We used soil and crop yield data from farmer participatory trials to parameterize the Agricultural Production Systems Simulator (APSIM) and evaluate its performance in simulating observed treatments at three locations in central Malawi. We used the calibrated APSIM model to investigate the performance of DLR and other maize-based systems across 26 growing seasons (1979–2005) in the three agroecologies. We simulated two DLR systems (maize rotated with a groundnut/pigeonpea or soybean/pigeonpea intercrop), maize rotated with groundnut or soybean, maize intercropped with pigeonpea, and continuous maize under a range of N fertilizer inputs. We extended findings to the household level by determining calorie and protein yields of these systems, and calculating the chance that an average household could meet their food requirements by dedicating all available farmland to a given system. Simulated maize grain yields in DLR and maize-grain legume rotations were essentially equivalent, and exceeded yields in maize/pigeonpea intercrop and sole cropped maize receiving comparable fertility inputs. All rotation systems were more likely to meet household calorie and protein needs than other systems receiving equivalent inputs. DLR systems accumulated higher total soil C and N over time than traditional rotation systems in areas where pigeonpea performed well. However, the effects of improved soil fertility on maize yields were counterbalanced by factors including N immobilization and water availability. We conclude that where growing conditions allow, DLR can harness the complementary phenology of pigeonpea to build soil quality for the future without reducing maize yields or compromising household food production in the immediate term.

A cropping system assessment framework—Evaluating effects of introducing legumes into crop rotations

Abstract Methods are needed for the design and evaluation of cropping systems, in order to test the effects of introducing or reintroducing crops into rotations. The interaction of legumes with other crops (rotational effects) requires an assessment at the cropping system scale. The objective of this work is to introduce a cropping system framework to assess the impacts of changes in cropping systems in a participatory approach with experts, i.e., the integration of legumes into crop rotations and to demonstrate its application in two case studies. The framework consists of a rule-based rotation generator and a set of algorithms to calculate impact indicators. It follows a three-step approach: (i) generate rotations, (ii) evaluate crop production activities using environmental, economic and phytosanitary indicators, and (iii) design cropping systems and assess their impacts. Experienced agronomists and environmental scientists were involved at several stages of the framework development and testing in order to ensure the practicability of designed cropping systems. The framework was tested in Vastra Gotaland (Sweden) and Brandenburg (Germany) by comparing cropping systems with and without legumes. In both case studies, cropping systems with legumes reduced nitrous oxide emissions with comparable or slightly lower nitrate-N leaching, and had positive phytosanitary effects. In arable systems with grain legumes, gross margins were lower than in cropping systems without legumes despite taking pre-crop effects into account. Forage cropping systems with legumes had higher or equivalent gross margins and at the same time higher environmental benefits than cropping systems without legumes. The framework supports agronomists to design sustainable legume-supported cropping systems and to assess their impacts.

Influence of Organic Based Technologies on Soil Nutrient Status in Semi-Arid Yatta Sub-County, Kenya

Declining soil fertility is the main cause of low and uncertain yields of sorghum and cassava traditional crops in arid and semi-arid areas of Kenya. Against this backdrop, this study investigated the effect of organic based technologies; application of organic fertilizers and integration of legumes in cassava and sorghum based cropping systems on soil chemical properties (Organic C, N, P and K). Field experiments were conducted in Katangi and Ikombe divisions of Yatta sub-County, Kenya during the short rain seasons (SRS) of 2010 and 2011 and long rain seasons (LRS) of 2011 and 2012. A randomised complete block design with a split plot arrangement was used. The main plots were three cropping systems: (i) intercropping (dolichos/cassava, dolichos/sorghum, pigeon pea/sorghum and pigeon pea/cassava); (ii) rotation (dolichos-cassava, dolichos-sorghum, pigeon pea-cassava and pigeon pea-sorghum); (iii) monocrop (cassava and sorghum). The split plots were organic fertilizers; Farm Yard manure (FYM), compost and control -no organic fertilizer added. Sorghum/dolichos+FYM had highest soil OC in LRS of 2011 at both sites and SRS of 2011 and 2010 at Katangi and Ikombe respectively. Cassava/dolichos+FYM had the highest soil OC in the SRS of 2011 and LRS of 2012 and 2011 at both sites. Sorghum/dolichos+FYM had highest soil N in LRS and SRS of 2011 in Katangi. Cassava-dolichos rotation accumulated highest soil N in SRS of 2010 and LRS of 2011 at both sites. Sorghum/dolichos intercrop accumulated higher soil P during the LRS of 2012 at both sites; and SRS of 2010 and LRS of 2011 in Katangi and Ikombe respectively. Cassava/dolichos intercrop produced higher soil P during the SRS of 2010 at both sites; and LRS of 2011 and SRS of 2011 in Katangi and Ikombe respectively. Higher soil K was observed under sorghum/dolichos intercrop in SRS of 2010 at both sites and LRS of 2011, SRS of 2011 and LRS of 2012 in Ikombe. Cassava/dolichos intercrop also had higher soil K during SRS of 2010, LRS of 2011 at both sites; LRS of 2012 at Katangi and SRS of 2011 at Ikombe. Application of FYM to sorghum/dolichos and cassava/pigeon pea intercrops is therefore a viable and sustainable trajectory to enhanced organic C and NPK levels in smallholder farming systems.

Changes in Soil Chemical Properties in Response to Application of Phosphorus Sources in Legume Sorghum Cropping Systems

Changes in Soil Chemical Properties in Response to Application of Phosphorus Sources in Legume Sorghum Cropping Systems Beldina A. Tunya; Joyce J. Lelei; Josephine P. Ouma; Ombui, P.N; Onwonga, R.N. Abstract Field experiments to evaluate effect of phosphorus (P) fertilizers and integration of legumes in sorghum cropping systems on soil pH, available nitrogen (N) and P, were conducted in Njoro Kenya during the short (SRS) and long rain seasons (LRS) of 2012 and LRS of 2013. The experiments comprised either lupin or chickpea grown with sorghum. The design was a split plot in a randomized complete block design. Main plots were cropping systems; sorghum monocrop, legume - sorghum rotation and legume- sorghum intercrop. Subplots comprised P sources (60 kg P ha- 1); triple super phosphate (TSP) and minjingu phosphate rock (MPR). Application of TSP resulted in significantly higher nutrient concentrations in the soil than MPR addition in the first season. In the second and third seasons, the performance of MPRs approached that of TSP. Legume crops due to their release and accumulation of carboxylic acid lowered the pH to below 5.5 thus making solubilization of MPR and availability of P possible. Intercropping sorghum with lupin or chickpea with application of MPR gave comparable results with use of TSP. Since MPR is cheaper than TSP, growing lupin or chickpea in intercropping system with sorghum with application of MPR is recommended for improved chemical properties. Full Text: PDF DOI: 10.15640/jaes.v3n4a11

Inclusion of grain legumes in rice based systems in the mid-hills of central Nepal

Grain legumes are the important crops for improving soil condition and dietary status of humans. These crops could improve both soil and human health if grown in the prevailing farming systems. Keeping these view in mind, participatory varietals selection (PVS) on lentil (Lens esculents L.), mung bean (Vigna radiata ) and cowpea (Vigna ungiculuta) was conducted in the central mid hills (Ramechha and Sindhuli districts) of Nepal. Five varieties of lentil (ILL 7982, ILL 6829, ILL 7537, ILL 7723 and Simal), four of mung bean (VC 3960, Kalyan, Pratiksha and Farmers' Local) and cowpea (Surya, Prakash, IT 86-2089-5F and America) were tested at different locations of those districts under rice-wheat-fallow and rice-fallow-maize systems during 2007 to 2009. All of those varieties were tested in farmers’ field condition keeping farmers as a replication in RCB design with ten replications for each crop. Agronomic practices were performed by farmers as and when necessary. Among the tested varieties of lentil, ILL 7982 produced the highest grain yield of 1347 kg/ha whereas Sital produced the lowest grain yield of 1003kg/ha. Similarly for mung bean, the variety VC 3960 gave the highest grain yield of 1145kg/ha and Pratiksha produced the lowest grain yield of 975 kg/ha. Likewise, among the tested varieties of cowpea, America gave the highest pod yield of 5320 kg/ha and Prakash gave the lowest pod yield of 3400 kg/ha. These varieties were identified suitable for further promotion in different cropping patterns such as rice-lentil- maize, rice-maize/mung bean, ricemaize/ cowpea systems. Simple economic analysis of the cropping systems under question indicated that inclusion of legumes in the systems seemed highly lucrative compared to maize and wheat. Therefore, it is anticipated that integration of legumes in the systems could enrich soil as well as it would be beneficial to farmers because of nutritional status attractive price in the market of these crops. DOI: http://dx.doi.org/10.3126/ajn.v1i0.7543 Agronomy Journal of Nepal (Agron JN) Vol. 1: 2010 pp.61-66