Effect of Combined Application of Humic Acid and Urea on the Wheat Growth and Yield

This paper aims to research the effects of combined application of humic acid and urea on the wheat yield and yield component, and establish rational fertilizer application scheme of wheat. Split plot experiment was adopted. Two types of phosphorus fertilizer (adding humic acid or not) was assigned to the main plot, and four types of top dressing modes (different amount of urea and humic acid urea) were used in subplots. Effects of combined application of humic acid and urea on the wheat yield and yield component were researched. 375 kg/ha ordinary DAP + 150 kg/ha urea was used as base fertilizer; topdressing of 300 kg/ha urea humate could effectively promote the plant height, leaf area coefficient and aboveground dry matter amount. Adding humic acid in urea in topdressing significantly enhanced the wheat yield and economic coefficient of wheat. Adding humic acid in urea in topdressing has better effects of yield increasing than base fertilizer, and can be used for large scale extension