Effect of Coffee Pulp Compost and P Fertilizer on Yield and Yield Components of Maize (Zea mays L.) in Gedeo Zone, Southern Ethiopia

Abstract Agricultural waste utilization in the form of compost is a sustainable alternative to fertilizer for increasing crop yield in smallholder farms. A study was conducted to investigate the effect of coffee pulp (CP) compost, phosphorus (P) fertilizer, and their combination on yield and yield components of maize in the Gedeo Zone, Southern Ethiopia, under rainfed conditions using maize variety BH140 as a test crop. The treatments consisted of four CP compost levels (0, 2.5, 5 and 7.5 t/ha) and four P levels (0, 10, 20 and 30 kg/ha) laid out in a factorial arrangement using a randomized complete block design with three replications. The analysis of variance revealed that there were significant (p ≤ 0.05) differences among the different levels of CP compost on tasseling date, ear length, 1000 seed weight, grain yield, biomass production, and harvest index of maize. P application had also a significant (p ≤ 0.05) effect on all measured yield components and final grain yield. Sole application of CP at the rate of 2.5 t/ha increased maize grain yield by 19% compared to control plots. Integration of CP compost at the rate of 2.5 t/ha with 30 and 20 kg P/ha increased maize grain yields by 63 and 60.85% compared to control plots, respectively. Thus, the integration of compost at the rate of 2.5 t/ha with 20 kg P/ha could be recommended for maximum grain yield. Farmers who cannot afford fertilizer would be encouraged to use CP compost at the rate of 2.5 t/ha.