Towards a cropping system sustainability tool (CROSST) - Pilot results from evaluating green manure cover crops in Benin and Kenya

Farming practices in sub-Saharan Africa have resulted in declining soil fertility. Hence, Green Manure Cover Crops (GMCC) are promoted for soil improvement and protection. Adoption of GMCCs by farmers, including integration in their cropping systems, requires a good understanding of the multi-dimensional impacts of these crops. We, therefore, developed the Cropping Systems Assessment Sustainability Tool (CROSST), which can compare the performance of different cropping systems with and without the integration of GMCCs. CROSST is an Excel-based tool that assesses both agro-environmental and socio-economic impacts of GMCC technologies. The tool quantifies gross economic margin, productivity (yield), soil health (N and P balances, soil structure, and soil organic carbon), required labour hours, and the trade-offs between these indicators. The tool was pilot-tested in Benin and Kenya under the BMZ-GIZ program on ‘Soil Protection and Rehabilitation for Food Security.’ Data was collected through literature reviews, focus group discussions and key expert interviews. The compared cropping systems were selected and designed by experts with in-depth knowledge on local contexts of Benin and Western Kenya. The first results indicate that GMCCs improve soil structure/soil organic matter as well as soil N balances in both countries. However, investing in soil improvement can result in loss of profitability, especially when a crop that produces grain for consumption or sale is swapped for a GMCC that produces biomass for soil amendment only. CROSST still needs further data refinement with recent official census as well as independent field measurements. Once validated, it can serve as a decision-support tool for development agencies, implementing partners, and local stakeholders when designing sustainable cropping systems that integrate GMCCs

CLEANED: A tool for ex-ante assessment of environmental impacts of livestock production – A case study on dairy production in Tunisia

In Tunisia, the dairy sector faces several productivity and competitiveness challenges, including a low processing rate of agricultural products, poor entrepreneurship among small farmers, and inadequate/unsustainable management of natural resources. For instance, water requirements for irrigation often exceed supply leading to irreversible depletion of aquifers. The main objective of the study was to assess the potential environmental impacts of the transformation of the dairy value chain in Tunisia, through a collaboration between the Alliance/CIAT, GIZ and partners. The specific objectives of the study were: • Assessment of the current environmental, climate and economic impacts of smallholder dairy farms in the project intervention areas (Gouvernorats of Jendouba and Sidi Bouzid) • Ex-ante impact assessment of proposed interventions (“best practices”) • Training of partners on the CLEANED tool Intensive dairy production systems in Tunisia depend to a large extent on off-farm (feed) resources. Therefore, the impact assessment distinguished four different “feed origins”: on-farm, off-farm roughages, off-farm concentrates and imported concentrates. Based on individual surveys, focus group discussions and soil and water quality analyses, baseline and “best practice” scenarios were developed for each farming system. Some conclusions: • “Best Practice” scenarios based on increasing on-farm legumes (e.g., as a mixed crop with cereals or tree crops) and roughages reduce concentrate, fertilizer, water and land requirements (including off-farm). In some systems GHG emission intensity reduces up to 40%. • The partial replacement of imported concentrates by on-farm feed reduces costs and improves the gross margin

A customizable microfluidic platform for medium-throughput modeling of neuromuscular circuits

Neuromuscular circuits (NMCs) are vital for voluntary movement, and effective models of NMCs are needed to understand the pathogenesis of, as well as to identify effective treatments for, multiple diseases, including Duchenne's muscular dystrophy and amyotrophic lateral sclerosis. Microfluidics are ideal for recapitulating the central and peripheral compartments of NMCs, but myotubes often detach before functional NMCs are formed. In addition, microfluidic systems are often limited to a single experimental unit, which significantly limits their application in disease modeling and drug discovery. Here, we developed a microfluidic platform (MFP) containing over 100 experimental units, making it suitable for medium-throughput applications. To overcome detachment, we incorporated a reactive polymer surface allowing customization of the environment to culture different cell types. Using this approach, we identified conditions that enable long-term co-culture of human motor neurons and myotubes differentiated from human induced pluripotent stem cells inside our MFP. Optogenetics demonstrated the formation of functional NMCs. Furthermore, we developed a novel application of the rabies tracing assay to efficiently identify NMCs in our MFP. Therefore, our MFP enables large-scale generation and quantification of functional NMCs for disease modeling and pharmacological drug targeting. © 2019 The Author