Abstract:
he extreme climate events such as El Nino seriously threaten crop production and agro-ecological sustainability be-cause of the aggravated environmental stresses worldwide, particularly in sub-Saharan Africa. To address this issue,we investigated the effects of dual plasticfilm and straw mulching in ridge-furrow (RF) system on wheat productiv-ity, soil carbon and nitrogen stocks in a semiarid area in Kenya from 2015 to 2017. The experimental site represents atypical semiarid continental monsoon climate, and soil type is chromic vertisols. Field experiment with randomizedblock design consisted of six RF treatmentsasfollows:1)dualblackplasticfilm and straw mulching (RFbS), 2) dualtransparent plasticfilm and straw mulching (RFtS), 3) sole black plasticfilm mulching (RFb), 4) sole transparentplastic mulching RF (RFt), 5) sole straw mulching (RFS) and6) no mulching (CK). The results indicated that seasonaldynamics of rainfall and air temperaturefit in with the weather type of El Nino over four growing seasons. RFbS,RFtS, RFb and RFt significantly increased soil water storage (SWS), topsoil temperature, aboveground biomass,grain yield and water use efficiency across four growing seasons (pb0.05) as compared with CK. Among all thetreatments, RFbS and RFtS achieved the greatest SWS, AgB, grain yield and WUE, owing to improved soil hydro-thermal status in both treatments. Critically, RFbS and RFtS significantly improved soil organic carbon and total ni-trogen, soil bulk density and the C:N ratio following four growing seasons, comparing with other treatments(pb0.05). Besides, RFbS and RFtS gave the highest economic returns among all treatments. For thefirst time, wefound that dual plasticfilm and straw mulching could serve as a sustainable land management to boost wheat pro-ductivity and improve soil quality under El Nino in semiarid areas of SSA.
