Effect of different fertilization modes on nutrients budget of crop-soil system

The nutrient budget of crop-soil system was analyzed based on the data from a consecutive 20-year field trial. The trial was consisted of eight fertilization treatments with different combinations of nitrogen (N), phosphorus (P), potassium (K) and recycled manure (M). Compared with treatments without M, M treatments averagely increased yields of soybean and maize by 22.9% and 16.4%, respectively. However, the yield increase due to M treatment was moderated by the application of chemical nutrients, especially that of N fertilizer. Although M application alone alleviated soil nutrient deficit, it did not facilitate high crop yield and well balance nutrient budget. P deficit was aggravated under the treatments with only N fertilizer. Application of N and P without K fertilizer resulted in high K deficiency. NPK+M treatment was the most appropriate fertilization mode for high crop yield and well balanced soil nutrient budget.