The rice (Oryza sativa L.) - wheat (Triticum aestivum L.) cropping system occupies about 28.8 million hectares mainly spread over Asias five countries, namely, India, Pakistan, Nepal, Bangladesh and China. Organic farming offers alternative system for sustainable production and natural resource system. The aim of nutrient management in organic systems is to optimize the use of on-farm resources and minimize losses. Organic materials such as farmyard manure, compost, vermicompost, biogas slurry, green manures, crop residues, biofertilizers and cover crops are other valuable source of...