Evaluating Intercropping (Living Cover) and Mulching (Desiccated Cover) Practices for Increasing Millet Yields in Senegal

Located within the Sahel region, Senegal faces several agricultural production challenges. Limited rainfall, poor soil fertility, and insufficient agronomic inputs all contribute to low pearl millet [Pennisetum glaucum (L.) R. Br.] yields. This study was initiated to assess the potential for increasing millet yields through intercropping (living cover) and mulching (desiccated cover) practices. During the 2013 and 2014 growing seasons, pearl millet was intercropped with cowpea [Vigna unguiculata (L.) Walp.], mungbean [Vigna radiata (L.) Wilczek], or grown under mulch (neem [Azadirachta indica] leaves applied at 2 t ha–1). Field trials were conducted at two sites within Senegal’s central millet– peanut (Arachis hypogaea L.) basin, in Bambey (14°41¢382 N, 16°28¢122 W) and iés (14°45¢452 N, 16°53¢142 W). Soil moisture and plant N (based on the normalized difference vegetation index [NDVI]) were measured in addition to yield. When inter- cropped with a legume, millet grain yields increased up to 55% compared to millet alone. The combined grain yields under inter-cropping (millet + legume) were always higher than yields of millet alone, up to 67% in Bambey. Mulching increased soil moisture up to 14%, with yield increases of up to 70% over millet with no mulch. Plant N increased in both intercropped and mulched millet, with NDVI increases up to 21% with mulch and 16% when grown with a legume (prior to flowering). These yield increases were achieved using resources that are available and affordable to small-scale producers in the region (seeds and mulch), and did not require the addition of fertilizer input.