CHAPTER SIX Productivity and Sustainability of the RiceeWheat Cropping System in the Indo-Gangetic Plains of the Indian subcontinent: Problems, Opportunities, and Strategies Bhagirath S. Chauhan * , Gulshan Mahajan y , Virender Sardana y , Jagadish Timsina * and Mangi L. Jat z Contents 1. Introduction 316 2. Problems 319 2.1. Diverse Agronomy of Rice and Wheat 320 2.2. Declining Water Availability and Groundwater Pollution 321 2.3. Deteriorating Soil Health 322 2.4. Disposal of Crop Residues 324 2.5. Weed Flora Shifts and Herbicide Resistance 326 2.6. Climate Change 328 3. Opportunities and Strategies 330 3.1. Conservation Agriculture 330 3.2. Crop Residue Management 338 3.3. Precision Land Leveling 340 3.4. Crop Diversification 341 3.5. Soil Nutrient Management 343 3.6. Reducing Water Requirements 344 3.7. Weed Management 346 3.8. Climate Change 352 4. Conclusions 354 Acknowledgments 355 References 355 * International Rice Research Institute (IRRI), Los Baños, Philippines y Punjab Agricultural University, Ludhiana, Punjab, India z International Maize and Wheat Improvement Center (CIMMYT), New Delhi, India Advances in Agronomy, Volume 117 Ó 2012 Elsevier Inc. ISSN 0065-2113, All rights reserved. DOI: http://dx.doi.org/10.1016/B978-0-12-394278-4.00007-6 315