Strip-till and conservation tillage improve soil physical quality, water-use efficiency, and soybean productivity under arid irrigated conditions

Abstract

This three-year field study evaluated conventional moldboard tillage (CT), localized strip-till (LT), and conservation chisel tillage with surface mulch (ConsT) for irrigated soybean production in the Samarkand region of Uzbekistan. The experiment was conducted from 2023 to 2025 in a randomized complete block design with four replicates under arid conditions, with seasonal precipitation 16–32% below the long-term mean. Averaged across years, ConsT reduced soil bulk density from 1.31 to 1.26 g cm −3 and penetration resistance from 2.15 to 1.64 MPa relative to CT. It increased water-stable aggregates from 58.2 to 68.3%, infiltration rate from 12.4 to 18.2 mm h −1 , and mean soil moisture in the 0–40 cm layer from 14.2 to 17.3%. Mean soybean grain yield increased from 3.40 t ha −1 under CT to 3.76 t ha −1 under LT and 3.94 t ha −1 under ConsT. Water-use efficiency rose from 0.825 to 0.943 and 1.019 kg m −3 , respectively. Soil electrical conductivity measured in a 1:5 soil–water extract did not differ significantly among treatments. The results demonstrate that reduced soil disturbance combined with residue retention improves soil physical quality, conserves water, and enhances soybean productivity under arid irrigated conditions.