Can legume crop residues contribute to sustainable intensification of rainfed rice production in Madagascar?

Rainfed agriculture on smallholder farms across the tropics is crucial for food security and livelihoods when availability of irrigated land is limited. Coarse-textured soils with low organic carbon and poor inherent fertility prevail in these systems (Tittonell and Giller,2013). In the absence of sufficiently remunerative market, small holders cannot afford mineral fertilizers so that nutrient inputs are generally limited to manure. Integrated soil fertility management, e.g. integration of legumes combined with additional supply of mineral fertilizers, is required to sustainably increase rainfed agriculture productivity (Vanlauwe et al. 2014). In Madagascar, most small holders do not use mineral fertilizer under rainfed agriculture. Incorporation of Nitrogen (N) rich crop residues could increase nutrient supply and improve N use efficiency(Aggarwal et al.,1997). Nutrient supply from residues is a complex process related to decomposition rates of residue, which is impacted by residue type and climate variability, e.g increased temperatures can accelerate residue decomposition while intense rainfall can increase the loss of the precious mineralized N through leaching. The potential contribution of N rich crop residues to increase staple crop productivity is therefore complex to anticipate. Soil-crop models can account for such complexity. This study aims at(i) calibrating the STICS crop model for rice yield modeling in the smallholder context of cool humid uplands in Madagascar and (ii) use the model to explore the effect of incorporation of rice and legume residues for low (25kgN ha-1) and high (160kg N ha-1) fertilizer inputs with a variable climate. The soil-crop model STICS (Brisson et al., 2003) was chosen for its capacity to account for soil water and nutrient dynamics during crop cycle for various climates and crop management. Rice experiments (cultivar NERICA 4) carried out in 2016-2017 and 2017-2018 cropping season in Ivory(19°33'S, 46°24'E, 950 m a.s.l)on Ferral sols were used for model calibration and testing. Two previous crops were compared: (i) rice and (ii)Mucuna cochinchinensis-Crotalaria spectabilis intercropping, combined with two levels of nutrient input, i.e. manure only (25kgN ha-1) or manure and mineral fertilizer (160kg N ha-1). Residues were incorporated at plowing. Measured data include rice phenology, above ground biomass and plant N, grain yield and in-season soil moisture and soil N. The calibrated STICS model reproduced adequately rainfed rice emergence, flowering and maturity, with on average an error of less than four days. Simulated in-season soil N and rice biomass agreed with the observations with a relative Root Mean Square Error from 33% to 36% (see Figure 1for rice residues with high N input treatment). The model could reproduce the additional mineral N supply and plant uptake associated with the incorporation of N rich legume residue for the two fertilizer treatments. Calibration for grain yield and scenario analysis using historical climate (1980-2010) are on-going and will allow to determine the profitability and risk associated with the different simulated options. This study will contribute to gain new insights on the relevancy of legume residue for sustainable intensification of cropping systems in a tropical smallholder context

Assessment of the impact of climate change in temperate zone on grain legume yield and N2 fixation. PS-4.1-05

Climate change is likely to strengthen abiotic stresses on crops in temperate zones. Grain legumes and the associated provision of ecosystem services are the cornerstone of more sustainable cropping systems, yet the impact of climate change on their performance has not been extensively quantified. Based on previous experiments carried out in south-western France with low biotic stress, we calibrated the STICS soil-crop model for spring pea (SP), winter pea (WP) and winter faba bean (WF) grown on two types of soil with available soil water ranging from 64 to 167 mm and evaluated its quality of prediction on an independent dataset. STICS was used to explore the effect of climate change scenarios on the legumes performance. Assuming no adaption of crop management, mean and inter-annual variability of grain yield and N2 fixation were assessed for historical (1995-2015), mid-term (2020- 2040) and long-term (2060-2080) periods, considering projections from two coupled atmosphere-ocean Global Circulating Models (GCM), and two Representative CO2 Concentration Pathways (RCP), i.e. RCP 4.5 and RCP 8.5. The GCMs consistently predicted no significant change in rainfall amounts but indicated a 1.7°C and 2.5°C increase in average temperature over the growth period in the long term under RCP 4.5 and RCP 8.5 respectively. Therefore, simulations indicated no extra water stress with future climate. The increase in temperature entailed a shortening in crop duration and a slight but significant increase in the temperature stress factor values for grain filling, for photosynthesis and for N2 fixation during the reproductive period (+1% to +13 % depending on temperature stress, crop and RCP). Under RCP 4.5, yield decreased by 23 to 34% (depending on crop) in the long term. Average fixed N2 decreased by 16% to 34%. Probability of yield failure (i.e. yield below the 20th percentile of historical yield) increased from 20 to 50, 54 and 58% for WF, WP and SP respectively. Probability of N2 fixation failure increased from 20 to 34, 50 and 53% for WP, WF and SP respectively. In contrast, under RCP 8.5, the CO2 fertilisation effect would offset the decrease in yield due to the shorthening in crop duration and simulations predicted a 8 to 13 % average yield increase in the long term. Average N2 fixation would increase by 15 to 23%. Probability of yield failure would increase from 20 to 21, 25 and 27% for WF, WP and SP respectively. Probability of N2 fixation failure would increase for SP (from 20 to 31%) but decrease for WF (from 20 to 13%) and WP (from 20 to 11%). The increased probability of yield and N2 fixation failure simulated with the RCP 4.5 scenario indicates the need for technical and transformational adaptations for grain legumes to deliver the expected ecosystem services with future climate. Under RCP 8.5, better yield and N2 fixation with elevated CO2 highlight the opportunity represented by climate change for inclusion of more grain legumes in cropping systems

Usages des résidus de récolte et gestion intégrée de la fertilité des sols dans les systèmes de polyculture élevage : étude de cas au Mali-Sud

Dans la zone du Mali-Sud, un des défis pour maintenir la fertilité des sols sous culture continue est d'aborder le partage ou le devenir des biomasses végétales produites par les cultures, nécessaires aux animaux de l'exploitation, d'une part, et au maintien sur le long terme d'un stock organique minimal au niveau de l'horizon de sol travaillé, d'autre part. Une étude a été conduite pour simuler des bilans simplifiés en carbone organique stable de sols cultivés au niveau de trois terroirs différenciés, à partir d'un seuil minimal théorique moyen à maintenir sur la profondeur 0 à 20?cm. Préalablement, nous avons quantifié les différents usages des résidus de récolte de dix exploitations par village selon la typologie couramment utilisée. Avec les pratiques dominantes actuelles de restitutions organiques (enfouissement dans le sol des litières de parcs associées à 25 % de la production totale de fèces de bovins et des reliquats de résidus de cultures restant à terre en fin de saison sèche), tous les types d'exploitation ont présenté des bilans organiques fortement déficitaires. Parmi les différents scénarios d'amélioration envisagés, celui incluant une augmentation de la biomasse produite par unité de surface, associée dans deux des trois villages à l'arrêt du brûlis des résidus et au doublement de l'apport en fèces, permettrait d'envisager un équilibre en termes de bilan organique pour la grande majorité des exploitations sur l'ensemble de leurs champs, tout en gardant le niveau de prélèvement actuel réalisé par les bovins lors de la vaine pâture ( Vp). Cette démarche originale, associant pratiques paysannes et bilans simplifiés en carbone stable (CS) du sol aux échelles de l'exploitation agricole et du terroir villageois, mériterait d'être appliquée dans d'autres situations au Mali-Sud et plus généralement dans d'autres contextes de polyculture élevage. (Résumé d'auteur

Model Intercomparison of Maize Response to Climate Change in Low-Input Smallholder Cropping Systems

Smallholder farming systems are characterized by poor soil fertility and low agricultural input use; process-based crop growth models can help quantifying the potential impact of climate change on productivity in these systems.With limiting conditions (water and nutrients), crop models need to rigorously account for soil water, nutrient, CO2, and temperature interactions when simulating climate change effects

Which options fit best? Operationalizing the socio-ecological niche concept

The large diversity of farms and farming systems in sub-Saharan Africa calls for agricultural improvement options that are adapted to the context in which smallholder farmers operate. The socio-ecological niche concept incorporates the agro-ecological, socio-cultural, economic and institutional dimensions and the multiple levels of this context in order to identify which options fit best. In this paper, we illustrate how farming systems analysis, following the DEED cycle of Describe, Explain, Explore and Design, and embedding co-learning amongst researchers, farmers and other stakeholders, helps to operationalize the socio-ecological niche concept. Examples illustrate how farm typologies, detailed farm characterization and on-farm experimental work, in combination with modelling and participatory approaches inform the matching of options to the context at regional, village, farm and field level. Recommendation domains at these gradually finer levels form the basis for gradually more detailed baskets of options from which farmers and other stakeholders may choose, test and adjust to their specific needs. Tailored options identified through the DEED cycle proof to be more relevant, feasible and performant as compared to blanket recommendations in terms of both researcher and farmer-identified criteria. As part of DEED, on-farm experiments are particularly useful in revealing constraints and risks faced by farmers. We show that targeting options to the niches in which they perform best, helps to reduce this risk. Whereas the conclusions of our work about the potential for improving smallholders' livelihoods are often sobering, farming systems analysis allows substantiating the limitations of technological options, thus highlighting the need for enabling policies and institutions that may improve the larger-scale context and increase the uptake potential of options

Which options fit best? Operationalizing the socio-ecological niche concept

Article Purchased; Published: 1st August 2016The large diversity of farms and farming systems in sub-Saharan Africa calls for agricultural improvement options that are adapted to the context in which smallholder farmers operate. The socio-ecological niche concept incorporates the agro-ecological, socio-cultural, economic and institutional dimensions and the multiple levels of this context in order to identify which options fit best. In this paper, we illustrate how farming systems analysis, following the DEED cycle of Describe, Explain, Explore and Design, and embedding co-learning amongst researchers, farmers and other stakeholders, helps to operationalize the socio-ecological niche concept. Examples illustrate how farm typologies, detailed farm characterization and on-farm experimental work, in combination with modelling and participatory approaches inform the matching of options to the context at regional, village, farm and field level. Recommendation domains at these gradually finer levels form the basis for gradually more detailed baskets of options from which farmers and other stakeholders may choose, test and adjust to their specific needs. Tailored options identified through the DEED cycle proof to be more relevant, feasible and performant as compared to blanket recommendations in terms of both researcher and farmer-identified criteria. As part of DEED, on-farm experiments are particularly useful in revealing constraints and risks faced by farmers. We show that targeting options to the niches in which they perform best, helps to reduce this risk. Whereas the conclusions of our work about the potential for improving smallholders’ livelihoods are often sobering, farming systems analysis allows substantiating the limitations of technological options, thus highlighting the need for enabling policies and institutions that may improve the larger-scale context and increase the uptake potential of options

Unlockit field lab on incentivizing reale state participants how blockchain is reshaping data sharing

To present a comprehensive analysis of the potential impact of Unlockit, a blockchain-based platform, on the Portuguese real estate market, our thesis delves into the intricacies of the market, highlighting the need for digital transformation to enhance transaction efficiency, transparency, and compliance. The study explores the application of blockchain and distributed ledger technologies (DLTs), examining models like EBSS and CoSC, and discusses their implications in real estate. A proposed business model for Unlockit suggests a subscription-based service with transactional fees, tailored to the sector's needs. Ultimately, we conclude that Unlockit could create true long-term impact on the real estate transactions in Portugal, despite challenges in scalability and regulatory compliance, offering a model for global market innovation with a phased approach