Effects of organic manure and crop rotation system on potato (Solanum tuberosum L.) tuber yield in the highlands of Awi Zone

Lack of sustainable soil fertility management system is a critical challenge in the highlands of Awi Zone. Important physicochemical properties of the soil are below the critical level to support crop growth. Hence, a study was undertaken with the aim of improving the yield of potato through organic treatments and sound crop rotation system. Two rotation systems and four levels of organic treatments were factorially arranged and laid out in RCBD with four replications. The organic treatments were: V1 = 0 t/ha farmyards manure (FYM); V2 = 2.5 t/h fresh sesbania green manure (FSB) V3 = 5 t/ha FYM; and V4 = 5 t/ha FYM +2.5 t/ha FSB applied in fixed plots for three years. Indeed, the rotation systems varied from year to year to estimate the changes in potato tuber yields due to the differences in crop rotation systems. Tuber yields of potato showed increasing trend over the period of the three years with the lowest in the first year, intermediate in the second year and the highest in the third year across all treatments. Among all, the highest total potato tuber yield (35.15 t/ha) was obtained at the combined application of 5 t/ha FYM +2.5 t/ha FSB and clover-wheat-potato rotation system in the third year. The treatment combination increased total potato tuber yield by 140% and 41% over that of the first and the second years and would be recommended as ecologically sound option in improving the productivity of potato. Keywords: Cropping system; farmyard manure; green manure; productivity; soil management