Nutrient Management Strategies for Chongqing

Initiated in 2001, the objective of this project is to study soil nutrient status and existing nutrient variability in fields of the region and to develop nutrient management techniques and systems capable of improving crop yield and farmers’ net benefit. Data from this study will be combined with information from other field trials and fertilizer use surveys collected from villagers.

In 2001, the nutrient limiting factors to crop growth were determined through extensive soil testing. In 2002, village field maps and nutrient variability maps were formed by using geographic information system software. Field trials were conducted to further substantiate soil test results and to determine a plan for balanced fertilization. The optimum nitrogen (N), phosphorus (P), and potassium (K) fertilizer treatment for paddy rice was 135-90-90 kg N-P₂O₅-K₂O/ha, which increased grain yield by 1,240 kg/ha (19%), compared with the zero P treatment and by 786 kg/ha (11%), compared with the low K treatment of 135-90-45 kg/ha. The optimum treatment used for rice also proved suitable for all crops in the wheat-corn-sweet potato cropping system.

The information shows potential for crop yield increase and quality improvement with balanced fertilization. This technology can be applied to the other similar regions in Chongqing. Chong-NMS05