Intercropping with Guiera senegalensis in a semi-arid area to mitigate early-season abiotic stress in A. hypogea and P. glaucum

Abstract

Recent research has shown that the native shrub, Guiera senegalensis J.F. Gmel, interplanted with crops dramatically increases crop yield in the Sahel. However, little is known about the crop development when grown alongside shrubs. The objectives were to determine the effect of shrub presence on crop development under varying fertilizer rates in northern Senegal. Peanut (Arachis hypogaea L.) and pearl millet (Pennisetum glaucum (L.)) response in the presence or absence of shrubs was investigated from 2013 to 2016 under low to adequate rainfall. The experiment had a split-plot factorial design with presence or absence shrubs (+shrub, −shrub) as the main plot (elevated densities of 1200 to 1500 shrubs ha−1) and fertilizer rate (0, 0.5, 1 or 1.5 times the recommended N–P–K rate) as the subplot factors. Major developmental phases, leaf counts and plant height were determined. Shrub presence made crops grow up to four times taller and reach 50% flowering when −shrub plots did not reach 50% in 2013 and 2015 (millet). Changes to crop development, even in low rainfall years, indicate that shrub intercropping buffers against crop water stress. Thus, under drought conditions, shrub-based agroforestry can contribute to reduce fertilizer necessity and to mitigate against climate change.