Assessing and Ranking Influence of Rates of Rice (Oryza Sativa L.) Straw Incorporation and N Fertilizer on Soil Physicochemical Properties and Wheat (Triticum Aestivum L.) Yield in Rice-Wheat System

Abstract:

The purpose of this study is to assess the individual and interactive effects of different rates of rice straw incorporation, Rsti, (0, 5, 7.5, and 10 t ha⁻¹) and nitrogen fertilizer, N, (0, 90, 120, and 150 kg ha⁻¹) on changes in physicochemical properties, available nutrients of surface soil, and wheat yield in a long-term rice-wheat system field experiment. Following rice in wheat crop, four rates of Rsti in the main plots and four rates of N in the sub plots were applied in a split-plot design with three replications. After wheat harvest of the 10th rice-wheat cropping cycle, triplicate soil samples were collected from 0 to 15 cm soil layer. Rice straw incorporation improved the soil organic carbon, soil aggregation, porosity, retention, and availability of water, as well as macro and micronutrients availability, and reduced resistance to root penetration, but increased soil bulk density. Wheat yield increased up to 7.5 t ha⁻¹ Rsti and N up to 120 kg N ha⁻¹. Among the assessed soil properties and available nutrients influenced by Rsti and N, supplementary soil organic carbon and available potassium were the top-ranked soil properties responsible for increased wheat yield. Wheat yield increased with rice straw incorporation was mainly due to increased soil organic carbon and available potassium.