Effect of tillage and weed management practices on soil physical and physico-chemical properties in rice under conservation agriculture

Abstract

The present study was aimed to evaluate the effect of tillage and weed management practices on physical and physico-chemical properties of rice under conservation agriculture. The field experiment was conducted at AICRP on Weed Management, College of Agriculture, PJTAU, Rajendranagar, Hyderabad, initiated in 2014 with rice- maize-green manure cropping system conducted for five years before the current season. The experiment was laid out in split-plot design with three replications comprised of five tillage practices as main plots (T1-CT (Conventional tillage)-CT, T2-CT-ZT (Zero-tillage), T3-CT (Direct seeded Rice)-CT, T4-ZT-ZT and T5-ZT+R (residue)-ZT+R and three weed management practices, W1-Chemical weed management, W2- Integrated weed management (IWM) amd W3-Unweeded control in subplots. The results showed that under different tillage practices, soil bulk density (BD) was highest under ZT-ZT at 0–15 cm (1.35 g cm⁻³) and at 15-30 cm, CT-CT(1.40) recorded higher BD. ZT treatments promoted larger macro-aggregates, Geometric Mean Diameter and Mean Weight Diameter, whereas CT treatments favoured micro-aggregates. Soil penetration resistance (SPR) was highest under ZT+R-ZT+R at 0–5 cm (1.28 MPa) and 5–10 cm (1.32 MPa), under CT(DSR)-CT at 10–15 cm (1.52 MPa), and under CT-CT at 15–30 cm. pH (8.46), CEC (30.23 Cmol (P⁺) kg⁻¹), soil organic carbon (7.8 g kg⁻¹) were highest in ZT+R-ZT+R and in contrast EC was highest under CT-CT 0.57 dS m-1. Weed management practices showed non significant effect on physical and physico chemical practices.