Integrated Soil-Crop System Management Reducing Environmental Risk While Increasing Crop Productivity and Nutrient Use Efficiency in China.

Integrated soil-crop system management reducing environmental risk while increasing crop productivity and nutrient use efficiency in China Fusuo Zhang, Mingsheng Fan, Xingping Chen, Xiaotang Ju, Zhenling Cui, Rongfeng Jiang Department of Plant Nutrition, China Agricultural University£¬Beijing 100193. Abstract Since 1949, especially when China initiated economic reforms and the open-door policy in the 1980¡¯s, China¡¯s economy has made great strides. The growth of agricultural production has been one of the main accomplishments of the country. China was successfully feeding 22% of the global population with only 9% of the world¡¯s arable land. Nevertheless, China¡¯s ¡®grain security¡¯ will face multiple pressures stemming from resource limitation, environmental pollution and population growth. The Chinese government is committing major resources to national research and extension programs in crop production. However, China must undertake a new step toward integrated soil-crop system management approach. Such an approach will focus on reducing environmental risk while increasing crop productivity and nutrient use efficiency. The key points of this strategy include (a) integrated use of nutrients from fertilizers, wastes and soil and environmental sources, (b) synchronization of nutrient supply and crop nutrient demand and application of different management technologies based on the characteristics of different nutrient resources, and (c) integration of nutrient management with sound soil management practices and other farming techniques such as use of high yielding cultivation systems, water-saving techniques, conservation tillage etc. Recent field experiments have demonstrated this integrated management approach can allow current N application rates to be reduced by 30-60%. This would still maintain crop yields and N balance in cropping systems, while substantially reducing N losses to the environment. This paper summarizes the systematic studies and national activities both in research and extension of soil-crop system management technology for reducing environmental risk while increasing crop productivity and nutrient use efficiency in China.