Study on the enhancement and mechanism of organic-inorganic compound fertilization on inorganic fertilizer utilization II. Effects of ammonium phosphate combined with organic material on

In this study, organic-inorganic compound P fertilizer was made by combining organic waste material (from monosodium glutamate factory) with ammonium phosphate, potted plant experiments (setting up three input rates of total P) were conducted to investigate effects of the compound P fertilizer on yield, nutrient uptake, nutrient use efficiency of maize under the same total P application rate. The results showed that compared to the chemical fertilizer treatment, the grain yield are increased by 19.1%, 11.3% and 37.8%, respectively under the low, medium, and high P application rates of the organic-inorganic compound P fertilization. The relative increases of maize grain yield of the organic-inorganic compound P fertilizer treatments to those of the corresponding organic material treatments are greater than those of the inorganic P fertilizer treatments to no P fertilizer treatments and the organic-inorganic P fertilization increases nutrients uptake of maize. Compared to the fertilizer P treatments, the P uptakes of maize plants are increased by 12.58%, 2.82% and 33.42%, respectively under the low, medium and high total P application rates of the organic-inorganic compound P fertilization. The organic-inorganic P fertilization increases P use efficiency. In the case of the same amount of total P applied, under the low, medium and high total P application rates, the organic-inorganic compound P fertilizer applications increase the inorganic-P apparent recovery by 14.85,1.22 and 16.04 percent, respectively, compared to the ammonium-phosphate treatment.