Effect of Biochar Application on Growth, Yield, and Yield Components of Potato in Logar Province

Abstract

Optimizing soil management is critical for improving potato (Solanum tuberosum L.) productivity in dry temperate regions such as Logar Province. This study was conducted at the Logar Province research farm. It evaluated the effects of eight biochar application rates (0, 5, 10, 15, 20, 25, 30, and 35 t ha⁻¹) on the growth, yield, and tuber quality of the Cardinal potato variety under the agro-climatic conditions of Logar Province, Afghanistan. A field experiment was conducted using a randomized complete block design (RCBD) with three replications. We measured vegetative traits, including plant height and the number of stems, branches, and leaves, alongside key yield components such as tuber number, weight, diameter, and marketable and non-marketable yields. Biochar application significantly increased tuber number, individual tuber weight, and marketable yield, while vegetative traits were largely unaffected, indicating a primary influence on belowground processes. The highest productivity and tuber quality were observed at 20 t ha⁻¹, which also minimized non-marketable tubers. Improvements are attributed to improved soil nutrient retention, water-holding capacity, and microbial activity. These findings provide empirical evidence supporting moderate biochar application at 20 t ha⁻¹ as a sustainable, cost-effective strategy to optimize potato yield, improve tuber quality, and enhance soil health in Logar province semi-arid agroecosystems.