掺混型控释肥对棉花产量及氮肥利用率的影响

为了合理高效利用控释肥，降低生产投入，采用田间小区试验，以不施肥（CK1）和施用等量普通尿素（CK2）为对照，对不同比例掺混型缓控释肥对棉花产量和氮肥利用率的影响进行研究。结果表明，较单施控释肥，掺混普通尿素处理有利于苗期棉株迅速增加有效光合叶面积，积累光合物质。收获时，各控释肥处理的籽棉产量均高于等氮尿素处理CK2。以T1（PCU100%）和T2（PCU70%+PU30%）增产效果最为突出，较生产对照CK2分别提高约16%和15%。考虑氮肥利用率指标，控释肥和普通尿素掺混处理较单施尿素均有不同程度的提高，提高幅度介于2%~13%之间。T2（PCU70%+PU30%）处理的氮肥利用率最高，为40.42%，比单施PU和PCU处理分别提高12.84%和4.34%，差异显著。实验说明，控释肥和尿素掺混不仅能促进棉株前期生长发育，还能提高产量和氮肥利用率。鉴于纯施控释肥成本较高，从节本增效的角度考虑，PCU和PU掺混比例为7:3时效果最佳。

Effect of Slow/Controlled-release Fertilizer on Cotton Yield and Apparent N Recovery Rates

In order to promote reasonable and efficient use of the slow/controlled-release fertilizer,and reduce agricultural production input,the effect of slow/controlled-release fertilizer on cotton yield and apparent N recovery rates was studied under field conditions.L22 was used and 4 types of controlled release N fertilizer treatments were applied.The results showed that T2,T3 and T4 treatment effectively increased leave area and aerial part dry weight comparing to T1 at seedling stage.The yield of unginned cotton of 4 types of controlled release N fertilizer treatments were higher than CK2,the practical effect of T1 and T2 was more prominent,with 16% and 15%,respectively.As far as fertilizer use efficiency was concerned,there was a striking increase under 4 types of controlled-release N fertilizer treatments compared to that of CK2,the range was between 2%-13%.The value of T2 was highest,increased by 12.84% and 4.34%,respectively,compared with that of CK2 and T1.In consideration of saving investment and raise economic benefit,the ratio of 7：3 between PCU and PU was optimal.