Effects of Ridge-Furrow Rainwater Harvesting with Biochar-Soil Crust Mulching on Soil Properties, Nutrients, and Alfalfa Fodder Yield in a Semiarid Agroecosystem

PurposeAlfalfa (Medicago sativa L.) production is adversely impacted by surface runoff and drought stress. This is particularly true for alfalfa planted in semiarid areas. Therefore, the development of erosion-tolerant management practice is crucial.MethodsA study was carried out in a completely randomized design, with 4 treatments (3 straw biochar application rates + flat planting (FP) as control), and 3 straw biochar application rates of 0 x 10(4) (no biochar (NB)), 3 x 10(4) (single straw biochar-soil crust (SSB)) and 6 x 10(4) kg hm(-2) (double straw biochar -soil crust (DSB)), respectively.ResultsMean runoff efficiency in SSB was 16.58% compared to no-biochar treatment (20.14%), and in DSB was 14.57%. From 2017 to 2020, NB had the highest R-2 value for the variation between runoff and rainfall and DSB had the lowest R-2 value. In comparison to FP treatment, application of biochar to SSB significantly (p < 0.05) reduced runoff and increased soil water storage. The difference in soil water storage between pre-sowing and post-harvesting during alfalfa growth season increased on average by 15.69% with NB practice compared to FP, and by 11.79% and 7.58% with SSB and DSB practices, respectively. The mean weight diameter (MWD) in SSB treatment was higher than that in DSB treatment, although soil nutrients were increased in the following order: DSB > SSB > NB > FP. After post-harvest, average yields in NB, SSB, and DSB treatments were higher than those in FP treatment by 8.16%, 25.71%, and 18.31% respectively. With a mean yield of 8607 kg ha(-1), SSB significantly increased alfalfa yield across all years.ConclusionEvidence from the four-year experiment suggested that biochar-soil crust made from a single straw significantly reduced surface runoff, increasing soil water storage, soil aggregate stability, soil nutrients, and alfalfa fodder yield. Based on our research, we advise using single straw biochar-soil crust to boost alfalfa fodder production in semi-arid regions.