Effects of Sulfur Coated Urea Combined with Regular Urea on Nutrient Absorption and Yield of Wheat

Objective The aim was to explore the efficient application of sulfur-coated urea on wheat, in order to make sure the effects of different slow-release fertilizer treatments on soil fertility, wheat plant nutrient absorption and yield.

Method Using Yangmai 33 as the test crop, five fertilization patterns of sulfur coated urea and ordinary urea were designed under equal nitrogen conditions for field plot experiments.

Result The available nitrogen contents in treatments of 60% sulfur coated base application + 40% sulfur coated slow-release fertilizer applied during the greening period (S₆S₄), 60% sulfur coated base application + 40% urea applied during the greening period (S₆U₄), and sulfur coated slow-release fertilizer combined with urea (5∶5), 60% base application + 40% urea applied during the greening period (SU₆SU₄) were higher than that of ordinary urea applied four times (CK) and 100% sulfur coated urea applied at once (S₁₀) in mature period. Among them, SU₆SU₄ had the highest content of available nitrogen, which was 136 mg/kg. The ammonium nitrogen contents in treatments of S₆S₄, S₆U₄, and SU₆SU₄ slightly increased, while the available phosphorus contents increased significantly. However, there was no significant difference in the ammonium nitrogen and available phosphorus content among the treatments. The soil available potassium contents in the S₆S₄, S₆U₄, and SU₆SU₄ treatments was significantly higher than that in the CK. There was no significant difference in the nitrate nitrogen content of soils treated differently. The wheat grain yield and plant nitrogen, phosphorus, and potassium nutrient accumulation were significantly increased in the treatments of S₆S₄, S₆U₄, and SU₆SU₄, with SU₆SU₄ having the highest yield of 9.20 t ha^-1. The number of ears and grains per ear were the main factors affecting wheat yield, and the SU₆SU₄ treatment had the highest number of ears and grains per ear among the five treatments.

Conclusion Under equal nitrogen conditions, the combination of sulfur coated urea and regular urea (5∶5) with 60% basal application and 40% topdressing during the greening period is a more high-yield and efficient nitrogen fertilizer application pattern for wheat.