Improving the productivity of millet based cropping systems in the West African Sahel: Experiences from a long-term experiment in Niger

Resource-poor farmers who are living in the harsh environments of West African Sahel (WAS) depend on subsistence orientated, low-input farming systems for meeting their livelihood needs. These largely extractive have resulted nutrient depletion, soil fertility decline, low productivity and land degradation. A study conducted over 25 years Niger, aimed to evaluate long-term effects organic mineral fertilizers, cropping (CS) millet cowpea crop productivity. The traditional millet/cowpea intercrop system without P fertilizer (TrM/C) was compared with four improved CS receiving fertilizer: sole (MM), (M/C), millet-cowpea rotation (M-C), M/C (M/C-C). Nitrogen (N) residues (CR) were applied alone or combination all five systems. CR always as mulch. produced lowest grain yields (GY) (0.02–0.43 t/ha). All (MM, M/C, M-C M/C-C) increased GY (TrM/C). MM 3 3.3 times TrM/C, respectively. M/C-C 4 4.2 more than that TrM/C system, revenue obtained system. Except lower combined cultivation cowpea. Compared provided 2 revenue. By providing 2.4 most productive Cowpea from 54% 56% Soil carbon decreased 46% 63% kept under natural vegetation fallow. 3.4 times. Over cropping, highest levels rainfall indicating role nutrients maintained cropping. improving water use efficiency, integrated management affected rainfall. We concluded cereal-legume based treated small doses fertilizers could be used sustainable • Intercropping increases deficiency phosphorus is limiting High leads due leaching run-off. Millet-cowpea lends itself an crop/livestock/farming.