The effects of slow-release nitrogen fertilization models on soil biological properties in rice-wheat cropping system.

摘要

Slow-release fertilizers (SRFs) are of great significance in enhancing fertilizer efficiency and improving soil fertility. The effects of different SRF application models on soil enzyme (sucrase, protease and urease) activity and soil microbes (actinomycetes, bacteria, fungi) as well as the microbial diversity were investigated in rice-wheat cropping system. The results showed that in comparison with no N control group, four N fertilizer application models (Urea, Slow-release-Urea (SR-Urea), SR-Urea/Urea, SR-Urea/Urea/Org.N) increased the soil enzyme activity and the number of soil microbes significantly in both wheat and rice soils. Compared to pure urea application model, the soil enzyme activity was higher and the number of soil microbes was greater in other three SRF models (SR-Urea, SR-Urea/Urea, SR-Urea/Urea/Org.N); particularly in SR-Urea/Urea/Org.N model, the activity of sucrase, protease and urease were increased by 5-38%, 4-15% and 2-5%, respectively, and the number of soil bacteria, actinomycetes and fungi were increased by 9-27%, 3-14%, 13-28%, respectively. In addition, microbial diversity index (Shannon's diversity index) of SR-Urea/Urea/Org. N model was increased by 15-103% compared to other fertilization models. The results indicated that combined application of SRF and organic manures was a good precaution to improve the soil biological properties and soil fertility in rice-wheat cropping system.