Effects of Biochar and Compost Application on Soil Properties and on the Growth and Yield of Hot Pepper (Capsicum annuum L.)

Improper depositions of organic waste threaten the environment. On the other hand, intensive soil cultivation, inappropriate utilization of inorganic fertilizers, and inadequate soil management practices in the study area resulted in soil fertility reduction and poor crop growth. The addition of organic fertilizers from organic waste (biochar and compost) to soil can be considered an environmental-friendly and climate-smart practice able to improve soil properties and the yield of crops. Thus, this study aimed at evaluating the potential of organic amendment with coffee pulp compost (CPC), coffee pulp biochar (CPB), and their combination (CPC_CPB) on selected soil properties and hot pepper yield. The field experiment was conducted in the 2020 and 2021 growing seasons by adopting a randomized complete block design with a factorial experiment using CPC, CPB, and CPC_CPB treatments in different application rates. Results indicated that, in both years, the maximum dose (4 t/ha) of biochar significantly improved the yield of hot pepper and some soil chemical properties such as pH, OC, TN, P, K, Ca2+, Mg2+ contents, and CEC. When 2021 is compared with the 2020 growing season in terms of hot pepper yield, the treatments 4 CPB, 10 CPC, and 7 CPC_CPB increased the yield by 4.61, 1.62, and 1.55%, respectively. Thus, an application rate of CPB at the rate of 4 t/ha is considered suitable to improve hot pepper yield and soil properties. Therefore, the highest dose of CPB, followed by CPC_CPB and CPC can be considered as suitable to improve both soil fertility and hot pepper yield.