Effects of Combined Application of Control-released Urea and Urea on Dry Matter Accumulation and Yield of Maize
Controlled-release urea (CRU) and urea (U) were used to investigate the effects of five proportions of controlled-release urea blended with urea (100% CRU,25% U+75% CRU,50% U+50% CRU,75% U +25% CRU,100% U) and two controls (no N fertilization,CK1),conventional fertilization (CK2,60% U as basal and 40% U top-dressed) on agronomic characters,dry matter accumulation and distribution,and yield in maize.Results were as follows:(1)Nitrogen supply could increase the plant height,ear height,and leaf area,compared to the CK2 treatment,the combination applications of controlled-release urea with urea could increase the plant height,ear height,stalk diameter,and leaf area,improvement effect of the mixing ratio of 75% treatment were the most strong among them.(2)Compared to the CK2 treatment,the combination applications of controlled-release urea with urea could meet demand of life on jointing stage,promote dry matter accumulation on silking stage,and dry matter quantity were improved finally,improvement effect of the mixing ratio of 50%-75% treatments were the most strong among them.(3)Compared to the CK2 treatment,the dry matter of the combination applications of controlled-release urea with urea were lower on distribution proportion of the stalk and leaf,however,the distribution proportion of grain increased,the most in the mixing ratio of 75% treatment.(4)With different ratio of controlled-release urea were always higher,the yield,1 000-kernel weight,the grains per spike,ear length,and ear diameter increased firstly and then gradually decreased.The yield of the mixing ratio of 25%,50%,75%,and 100% increased by 3.70%,8.83%,11.23%,and 5.43% than the CK2.Therefore,applying controlled-release urea with a mixing ratio of 75% of basal dressing was most beneficial to meet the demand of life of maize,promote dry matter accumulation and distribution,and also could increase yield.
control-released ureamaizeyielddry matter accumulation and distribution