Approaches for sustainabillity of rice (Oryza sativa)-wheat (Triticum aestivum) cropping system in Indo-Gangetic plains of India - A review

This paper describes the results of some innovative approaches for sustaining productivity of rice-wheat cropping system in the Indo-Gangetic plains. Integrated nutrient management with green manuring as a substitute saved 50 of the chemical fertilizers, with an average productivity of rice (4.8 Vha) and wheat (3.3 Vha). Site-specific nutrient management using judicious application of primary, secondary and micronutrients as per soil test and specific yield target was also found an economically-viable option with benefit: cost ratio of 4.9 under multi-location trials, with 15-17 Vha of productivity of rice and wheat. Resource conservation technologies (RCT) like zero tillage, bed planting and laser land leveling saved substantial quantity of irrigation water. Zero tillage saved 20 irrigation water, along with saving of 300 million litres of diesel per annum. Likewise, bed planting saved 37.5 em irrigation water. Laser land leveling led to 18.4 saving of water and higher water productivity (1.19 kg grain/m3 water) in wheat under on-farm trials. The average water productivity in wheat under on-farm trials in Punjab was 0.33 and 0.52 kg grain/m3 water under no levelling and laser leveling, respectively. Happy seeder gave 7-8 higher pro¬ductivity and retained 5-7 Vha rice crop residue for soil fertility improvement. Besides water-saving and direct productivity gain, RCT was a valuable option for reducing the cost of cultivation in terms of land preparation, timely sowing, decreased seed rate, improved water and nutrient-use efficiency, and left indirect effect on mitigating the adverse effect of climate change. Remote-sensing technology also proved valuable for decision-support system in N saving, based on management-zone approach.