Abstract:

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 increases 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 is optimal.