Rice residue incorporation and nitrogen application: effects on yield and micronutrient transformations under rice–wheat cropping system

Abstract

Despite being a major domain of global food supply, rice–wheat (RW) cropping system is questioned for its contribution to biomass burning in Indo-Gangetic Plains (IGP). Enhancing the yield and soil quality properties in this system is therefore necessary to reduce environmental degradation and maintain agricultural productivity. A field experiment evaluated the effects of soil management practices such as rice residue (RS) incorporation, and nitrogen (N) application on crop yield and micronutrients transformations in a RW cropping system of north-western India. The results revealed that N application (120 kg N ha⁻¹) and RS incorporation (7.5 t ha⁻¹) significantly increased micronutrients cations and crop yield compared with no-residue (RS₀). Irrespective of N application, crop grain yield under RS incorporation (Rs_7.5 t ha⁻¹) was significantly higher than RS₀ incorporation. Significant increase in all the micronutrient transformations was recorded in N₁₂₀/Rs_7.5 t ha⁻¹ compared with RS₀. Among different fractions, crystalline Fe bound in Zn, Mn, and Cu and amorphous Fe oxide in Fe fractions were the dominant fractions under N application (N₁₂₀) and RS incorporation (RS_7.5) treatment. Our study showed that application of N₁₂₀ followed by RS_7.5 can be more sustainable practice under RW cropping system for improvement in micronutrients availability and crop yield. This practice also provides an opportunity to incorporation of crop residues as an alternative to burning, which causes severe air pollution in the RW cropping system in the IGP.

Keywords:

• micronutrients transformation
• rice residue
• rice–wheat

Acknowledgment

The authors acknowledge the technical facilities provided by Head, Department of Soil Science, Punjab Agricultural University, Ludhiana, India