Fertilizer recommendation for maize in China based on yield response and agronomic efficiency

• Soil indigenous nutrient supply, yield response and agronomic efficiency were analyzed in the main maize-producing regions in China.
• The relationships among yield response, soil indigenous nutrient supply, and agronomic efficiency were determined.
• A new fertilizer recommendation method has been built based on yield response and agronomic efficiency.
• Nutrient Expert for Hybrid Maize decision support system can be used without soil testing and no need collect experimental data from every field.

A generic but flexible and location-specific fertilizer recommendation method is necessary due to inappropriate fertilization in China. A new fertilizer recommendation method, Nutrient Expert (NE) for Hybrid Maize, was developed using maize datasets from 2000 to 2010 in main maize production areas. The results showed that the average of indigenous nutrient supply were 130, 41 and 124 kg/ha, the mean of yield response were 2.1, 1.2, and 1.2 t/ha, and the average agronomic efficiency were 11.4, 15.7, and 11.8 kg/kg for N, P, and K, respectively. There was a significantly negative exponential relationship between yield response and indigenous nutrient supply, and a significant negative linear relationship between yield response and relative yield. Analysis also indicated that the quadratic curve relation was obvious between yield response and agronomic efficiency. NE system was established based on yield response and agronomic efficiency (AE) through above analysis, and on-farm field experiments were conducted in 408 farmers’ fields to validate this system at seven provinces in China. The results showed that fertilizer recommendation based on NE method could maintain grain yield and profitability and improve nutrient use efficiency through 4R nutrient stewardship and it is proved to be a promising approach for fertilizer recommendation when soil testing is not timely or not available.