Water Yam (Dioscorea alata L.) Growth and Tuber Yield as Affected by Rotation and Fertilization Regimes across an Environmental Gradient in West Africa

Yam (Dioscorea spp.) is a staple food crop and source of income for millions people in West Africa. Traditionally, Africa, yams are grown without any external inputs, leading to low tuber yields. The rapid decrease yield observed after the first yam cropping season has been ascribed nutrient depletion and/or accumulation yam-specific pests diseases. This led farmers grow on new surfaces under fallow each year. Using transdisciplinary approach, we identified different yam-based rotations fertilization regimes that could stabilize production rotational systems improve water (D. alata) productivity. These innovations were tested researcher-managed field trials established along an environmental gradient crossing four growing zones spanning from Humid Forest (Liliyo Côte d’Ivoire) Derived Savanna/Forest Transition (Tiéningboué d’Ivoire), Southern Guinean Savanna (Midebdo Burkina Faso), Northern (Léo Faso) between 2016 2018. factor implemented at site included control with no (NON), sole mineral as NPK (MIN), combined organic (MINORG) manure (ORG), while rotation cereal (YamCer), legume (YamLeg), white (YamYam). average yields 32.8, 20.3, 2.7, 2.5 t fresh matter ha?1 2016, 16.4, 10.7, 8.9, 5.2 2018 Liliyo, Tiéningboué, Midebdo, Léo, respectively. most important determinants total amount rainfall recorded during period initiation maximum canopy development, soil carbon stocks 0–30-cm layer. We confirmed this study surface coverage measured 70 98 days planting was early indicator yield. Fertilization impacted positively cover but had weak impact Rotation either or lack observable impacts partly due very large variability yields, variable rainfall, anthracnose attack two sites should be studied over longer periods. is, our knowledge, publication showing relative site-specific properties (rainfall stocks) versus management practices going across African belt.