Under tropical meteorological conditions, the volume of soil explored by plant roots is crucial for crop growth as it allows increased water and nutrient use efficiency. We hypothesized that, under different irrigation intervals, leguminous mulch can extend the duration between irrigation events but maintain crop performance, because decreased evaporative fluxes also reduce constraints to root exploration imposed by mechanical stress. We evaluated the combined effects of leguminous mulch and irrigation intervals on soil physical properties to determine whether the growth and productivity of maize were modified in a structurally fragile tropical soil. The experiment involved the following treatments: 4‐day irrigation intervals with soil mulched (4C) or bare (4S), 6‐day irrigation intervals with soil mulched (6C) or bare (6S), 8‐day irrigation intervals with soil mulched (8C) or bare (8S) and 10‐day irrigation intervals with soil mulched (10C) or bare (10S). Mulch decreased soil penetration resistance and increased to 4 days the favourable time for root development in drying soil. Relative to bare soil, mulch with a 6‐day irrigation interval almost doubled nitrogen uptake post‐tasselling, which decreased nitrogen remobilization and increased the crop growth rate during this stage. These conditions had a positive effect on the transpiration rate and stomatal conductance as well as on the growth and yield of maize. A 6‐day irrigation interval with mulch compared to 4 days with bare soil resulted in similar conditions for root development, but greater uptake of nitrogen (102.73–78.70 kg/ha) and better yield (6.2–5.3 t/ha), which means greater efficiency in nitrogen and water use.

Highlights Legumes provide ecosystem services increasing maize yield in Amazonian agrosystem. Base cations, organic matter, nitrogen uptake are increased by leguminous biomass. Ecosystem services style approach can ensure feasibility in Amazonian agrosystems.

Agricultural growth is essential for both alleviating poverty and feeding the population of the Brazilian Amazonian periphery, where slash-and-burn agriculture continues to support the livelihoods of between 3.5-4 million people. We developed a new integrated-crop-livestocksystem named "no-till in alley cropping using leguminous tree mulch" in partnership with local communities, to replace shifting cultivation in the region. Although such technologies have proven their agronomic efficiency, they must also meet farmers' needs. Therefore, this study aimed to capture farmers' perceptions about how the new technology compares with conventional agricultural systems with a view to identifying barriers to the adoption of the new system. Our results indicated low levels of resistance by farmers to the new integrated-crop-livestock-system although we identified a lack of knowledge about sustainable soil management approaches like no-till systems. From an adoption point of view, this might indicate that farmers found the new technology rather complex compared to slash-and-burn and did not fully understand that it contributed to sustainable soil management. In addition, the cost of deploying the new technology was found to be a critical barrier; mainly because agricultural activity is closely linked to familybased food consumption, rather than quality improvement and value-added for sale. We concluded that there is an opportunity to replace shifting cultivation by sustainable agricultural intensification in the humid tropics. This new approach may help to overcome weaknesses which have prevented farmers from taking advantage of available ecosystem services in regions dominated by shifting cultivation such as the Brazilian Amazonian periphery. Keywords New technology . Ecosystem services . Farmers perceptions . Slash-and-burn agriculture . Family farming . Social development