Integrated nutrient management for improving crop yields and nutrient utilization efficiencies in China

China is now successfully feeding 22% of the global population with only 9% of the world's arable land, and per capita food availability has now reached the levels of developed countries. Increasing the amounts of inputs (e.g., fertilizers and water) has played a crucial role in agricultural intensification. However, the total consumption of chemical fertilizers in China exceeded 53.15 Mt (52.31 M tn) in 2007, nearly 35% of the total global consumption. Fertilizer applications are often not based on real-time nutrient requirements of the crop and/or site-specific knowledge of soil nutrient status. This has led to low resource efficiency, declining annual growth rates in crop yields and damage to the environment. It is therefore a matter of some urgency to develop nutrient management technology to meet increasing crop yields with enhanced nutrient efficiencies and sustaining the environment. With the support of the Chinese Ministry of Agriculture and the National Natural Science Foundation of China, we have carried out a large-scale project since 2003 that features integrated nutrient management (INM) systems. A total of 1,517 experiments have been conducted covering 12 cropping systems at 123 sites in 20 provinces to test the principles of INM.