[Effects of different slow/controlled release fertilizers on yield, quality of fresh maize and ammonia emissions]. / 不同缓控释肥对鲜食玉米产量、品质及氨挥发的影响.

ABSTRACT

A field experiment with five treatments, control (CK, no fertilizer), conventional fertilization (U), double-effect inhibitor synergistic urea (DU), coated urea (CU) and slow/controlled release urea mixture (CDU), was conducted to investigate the effects of conventional fertilization (240 kg N·hm-2) and one-off application of different slow/controlled release fertilizers (180 kg N·hm-2) on the yield and quality of fresh maize, soil inorganic nitrogen (N), and ammonia (NH3) emissions. The results showed that the total amount of ammonia volatilization was the highest in treatment of conventional fertilization (U), with N topdressing being an important source of NH3 emission. Compared with U treatment, the NH3 volatilization in the DU, CU, and CDU treatments was reduced by 78%-81%. At harvest stage, the soil layer of 80-100 cm in the U treatment had the highest nitrate concentration (51.6 mg·kg-1), resulting in a high risk of N leaching. In contrast, the nitrate concentrations in the same soil layer in the slow/controlled release fertilizer treatments were much lower, reducing the risk of leaching. In comparison with U, three slow/controlled release fertilizer treatments with 25% lower N application did not decrease yield but increased seed Vc, soluble sugar and protein contents. The agronomic efficiency and economic benefit of DU treatment were the highest among three slow/controlled release fertilizers treatments. In conclusion, the application of new type of slow/controlled release fertilizer could improve the yield and quality of fresh maize, and significantly reduce the risk of ammonia loss and N leaching. Considering the higher cost of the polymer coated urea, the double-effect inhibitor urea has lower cost and is more convenient to make. It is therefore a better choice to fresh maize planting.