Effects of different ratio of N forms on soil enzyme activities in winter wheat rhizosphere

Effects of five proportions of nitrogen forms (NH4+-N:NO3--N were 0：100, 25：75, 50：50, 75：25, 100：0, denoted as N1、N2、N3、N4、N5, respectively) on winter wheat (cv. strong gluten wheat Zhengmai 366 and weak gluten wheat Zhengmai 004) rhizosphere soil protease, urease, invertase and amylase activities were investigated under field condition.The results showed as following, N2 treatment (NH4 +-N:NO3 --N was 25:75) could effectively improve the rhizosphere soil enzyme activities of Zhengmai 366.Compared with N1 treatment, protease, invertase and amylase activities were improved by 19.85%, 4.78% and 15.92% in the N2 treatment. And compared with N5 treatment,they were improved by 57.28%, 5.89% and 25.16% in the N2 treatment.While the N3 treatment (NH4+-N:NO3--N was 50:50) was more favorable to increase the rhizosphere soil enzyme activities of Zhengmai 004, compared with N1 treatment , invertase and amylase activities were improved by 16.89% and 11.01% in the N2 treatment. And compared with N5 treatment, they were improved by 8.06% and 28.99% in the N2 treatment. Comprehensive comparison analysis showed that,different ratios of nitrogen forms can effectively regulated the soil activities in wheat's rhizosphere, and then improved the soil environment where the winter wheat would better growth and development.