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Rapid changes in agricultural systems call for profound changes in agricultural research and extension practices. The Diagnosis, Design, Assessment, Training and Extension (DATE) approach was developed and applied to co-design Conservation Agriculture-based cropping systems in contrasted situations. DATE is a multi-scale, multi-stakeholder participatory approach that integrates scientific and local knowledge. It emerged in response to questions raised by and issues encountered in the design of innovative systems. A key feature of this approach is the high input of innovative systems which are often although not exclusively based on conservation agricultural practices. Prototyping of innovative cropping systems (ICSs) largely relies on a conceptual model of soil–plant–macrofauna–microorganism system functioning. By comparing the implementation of the DATE approach and conservation agriculture-based cropping systems in Madagascar, Lao PDR, and Cambodia, we show that: (i) the DATE approach is flexible enough to be adapted to local conditions; (ii) market conditions need to be taken into account in designing agricultural development scenarios; and (iii) the learning process during the transition to conservation agriculture requires time. The DATE approach not only enables the co-design of ICSs with farmers, but also incorporates training and extension dimensions. It feeds back practitioners’ questions to researchers, and provides a renewed and extended source of innovation to farmers.

Transitioning toward minimum or no tillage is challenging for smallholder farmers in sub-Saharan Africa (SSA), due to the possible yield penalties during the initial years of a transition. Understanding the early impacts of such transitions is crucial in a cash crop such as cotton, on which farmers rely for their income, and is necessary to inform agroecological strategies to cope with both these challenges. This study explores the combined impact of minimum or no tillage and fertilizer regimes on agronomic parameters of cotton–cereal rotations, as practiced by smallholder farmers in Benin. A multilocation experiment was set up in three different agroclimatic zones, namely, Savalou (7°55′41″, 1°58′32″), Okpara (2°48′15″, 7°72′07″), and Soaodou (10°28′33″, 1°98′33″). In each area, the experiment was laid out as a split-plot design with four replications (main plot = soil preparation; subplot = fertilizers regimes). The treatments consisted of three different forms of soil preparation, namely, tillage, strip tillage, and no tillage or direct seeding, and four fertilization regimes, namely, basal mineral fertilizers (BMF, 200 kg ha1 of N14P18K18S6B1 + 50 kg ha1 of urea), BMF + A (200 kg ha1 of calcium phosphate amendment, 22P2O5-43CaO−4S), BMF + C (400 kg ha1 of compost), and BMF + A + C. At all sites, direct seeding led to lower below-ground biomass growth and seed cotton yields compared with conventional tillage in an early transition to conservation agriculture starting from degraded soils (2% to 25%). Weak rooting under direct seeding resulted in lower cotton yields compared with that under tillage (−12%) and strip tillage (−15%). At 45 and 90 days after emergence, cotton plants were shorter under direct seeding compared with tillage (−9% and −13%, respectively) and strip tillage (−23% and −6%, respectively). Fertilizer regimes affected seed cotton yields differently across sites and treatments, with marginal responses within soil preparation methods, but they contributed to increase yield differences between conventional and no tillage. Considering the need for sustainable practices, in the context of degraded soils and poor productivity, such limited yield penalties under CA appear to be a reasonable trade-off in the first year of a transition. Alternatively, the results from the first year of this experiment, which is meant to continue for another 5 years, suggest that strip tillage could be a sensible way to initialize a transition, without initial yield penalties, toward more sustainable soil management.

Individual Conservation Agriculture (CA) practices are not new to the West and Central Africa (WCA) region, though the combination of the three main components of CA is innovative. This chapter describe the main challenges in the adoption of CA while highlighting the diversity of practices related to soil, environmental and farm management practiced in the region. Practices consistent with CA include soil and water conservation measures, agroforestry and integration of crops and livestock, which can be used as catalysts for developing and upscaling CA. The chapter highlights challenges ranging from policy commitment to training and farmer attitudes. There also needs to be more accurate information on the extent and development of CA in the region. CA has great potential for increasing food security, addressing climate change and protecting natural resources.

Transhumant pastoralism is an ancient natural resource management system traditionally connecting ecosystems across north-south precipitation gradients in West Africa. As rural population grew, several governments in the region have promoted their settlement, i.e., the “sedentarisation” of nomadic pastoral peoples to avoid conflict over land use and access to resources with local sedentary populations. Former transhumant pastoralists settled down and started growing crops using the manure of their livestock. This led to the dwindling of traditional agreements and exchanges (manure against crop residues) between pastoralists and agriculturalists, that resulted in less nutrients flowing between livestock, food crops and the main cash crop in the region: cotton. As a consequence, soil fertility declined, grazing areas are overexploited, and crop production is increasingly dependent on mineral fertilizers, which are produced outside the region, exposing the livelihood of local farmers to the volatility of international (oil) markets. How do local farmers perceive the effect of this virtual “privatization” of natural resources? Is the production of cotton, a main agricultural export of west African countries, a viable option in this new situation? What does this imply for the research and policy agendas to support agricultural development? We explored these questions through engaging in discussion with farmers, herders and extension agents in three cotton growing zones of Benin.