Influence of Tillage and Nitrogen Management on Soil Nutrient Status, Soil Microbial Properties and Wheat Yield in Rice-Wheat Cropping System

AbstractThe study investigates the effects of different tillage practices and nitrogen (N) management strategies on soil nutrient status, microbial properties and wheat yield within a rice-wheat cropping system in the Indo-Gangetic Plains. A split-plot field experiment was conducted with four tillage methods—conventional tillage, stale seedbed followed by conventional tillage, zero tillage without residue, and zero tillage with residue retention and four N management strategies, including control, recommended N application, modified N scheduling, and Leaf Colour Chart (LCC)-guided N application. Results showed that zero tillage with residue retention (ZT+R) significantly enhanced soil properties recording the highest soil organic carbon after harvest (0.44%), available phosphorus (21.8 kg ha-1), available potassium (358.6 kg ha-1) and increased microbial activity (microbial biomass carbon (MBC) of 155.92 µg g-1 soil and fluorescein diacetate activity (FDA) of 127.94 µg g-1 soil). ZT+R also produced the maximum grain yield (4.99 t ha-1) and straw yield (8.03 t ha-1) compared to other tillage methods. Among N management strategies, the LCC-guided N application achieved the highest grain yield (5.39 t ha-1) and also recorded the highest MBC (157.42 µg g-1 soil), FDA (117.64 µg g-1 soil) and available potassium after harvest (355.6 kg ha-1). These findings highlight the potential benefits of conservation agriculture practices such as zero tillage with residue retention and precision N management for sustainable wheat production in rice-wheat cropping systems.