Journal of Chongqing Industry Polytechnic College.
2022, 4(4):
26-34.
Agriculture in China is dependent on imported potash fertilizer; potash reductions with slow/controlled release fertilizers are, therefore, important for development of sustainable agriculture. We studied the effects of slow-release compound fertilizers with 10% and 30% reductions in potassium (SRF1 and SRF2, respectively) on the rhizosphere soil microbes of three kinds of leafy vegetables (cabbage, Brassica narinosa, and lettuce) in Tongliang and Beibei experimental fields (representing soils with different potassium levels). The results showed that in the Tongliang experimental field, the bacterial, actinomycetes, and fungal content was significantly higher in the rhizosphere soil of B. narinosa than in cabbage and lettuce. Compared with compound fertilizer (CF), SRF1 significantly increased the rhizosphere soil microbial content of cabbage, B. narinosa, and lettuce in the Tongliang experimental field by 11.5%, 27.7%, and 22.2%, respectively. The rhizosphere soil actinomycetes content of lettuce in the Beibei experimental field increased significantly by 18.0% compared with CF and 16.4% compared with common compound fertilizer (CCF). Compared with CF, SRF1 and SRF2 significantly increased the rhizosphere soil fungal content of cabbage by 13.4% and 12.9%, respectively, in the Tongliang experimental field. In this field, the gram-positive and gram-negative bacterial content of the rhizosphere soils of cabbage, B. narinosa, and lettuce treated with slow-release compound fertilizer were significantly higher than in those treated with CF and CCF. Therefore, among the different fertilizer treatments, the application of slow-release compound fertilizer with a 10% reduction in potassium (SRF1) produced the best effects on rhizosphere soil microbes.