Release characteristics of nutrients of uncoated slow release compound fertilizer and nutrient uptake of wheat

Simulation of soil incubation and pot experiment methods were adopted to study the release characteristics of the nitrogen, phosphorus and potassium nutrients of uncoated slow-release compound fertilizer(SRF) and common compound fertilizer(CCF), and effect on nitrogen uptake and use efficiency of wheat, in order to evaluate SRF in "soil-plant" system. Results showed that the nitrogen, phosphorus and potassium of SRF had better slow release capability than those of CCF in simulated soil incubation experiment. The release quantities of the three nutrients were in the order of N>K>P and were in similar to nutrient characteristics of wheat. Before tillering stage, the nutrient uptake by wheat of CCF was higher than those of SRF. But after this stage, there was in reverse order. Compared to the CCF, SRF could increase the root, shoot, seed, and yield by 18.0%, 7.55%, 12.4%, and 14.9%, respectively. And the nitrogen, phosphorus and potassium use efficiencies of SRF were increased by 23.6%, 15.4% and 63.7%, respectively. The dynamics of nutrient release of two compound fertilizers could be quantitatively described by cubic regression equation(r＝0.9285^**～0.9968^**). As a result, the effect of SRF was better than CCF in "soil-plant" system.