Effect of rice mulch on irrigated wheat growth, yield and water productivity

Rice-wheat cropping systems are of great importance in providing a secure food source in India, but in areas such as north-west India where crop production is largely mechanised, rice-crop residues are a major obstacle to the timely and efficient sowing of wheat. Consequently, in situ burning of rice residues prior to sowing wheat is commonly practiced. This causes severe air pollution and loss of nutrients and organic matter. The recent development of the •Happy Seeder– sowing combine provides the ability to sow crops directly into rice residues, with potential benefits for soil moisture conservation and crop yield. To study these potential benefits, field experiments were conducted for two wheat seasons in Punjab, India, during 2006-08. The field data were also used to parameterise and calibrate the APSIM-Wheat model, which was used to further explore the effects of mulch on crop performance, irrigation requirement, components of the water balance and water productivity.Mulch increased soil water content, and this improved crop growth and yield determining attributes where water was limiting, which occasionally led to a significant increase in grain yield.