Abstract: Field trials of organic farming were conducted to examine the effects of different bio-fertilizers on the organically cultured cucumber growth, soil enzyme activities, and soil microbial biomass. Four treatments were installed, i.e., organic fertilizer only (CK), bio-fertilizer “Zhonghe” combined with organic fertilizer (ZHH), biofertilizer “NST” combined with organic fertilizer (NST), and bio-fertilizer “Bio” combined with organic fertilizer (BIO). Bio-fertilizers combined with organic fertilizer increased the cucumber yield significantly, and improved the root growth and leaf chlorophyll content. Comparing with that in CK, the cucumber yield in treatments ZHH, NST, and BIO was increased by 10.4%, 12.4%, and 29.2%, respectively. At the seedling stage, early flowering stage, and picking time of cucumber, the soil microbial biomass C and N in treatments ZHH, NST, and BIO were significantly higher than that in CK, and the activities of soil urease, acid phosphatase, and catalase were also higher.

Key words: bio-fertilizer, organically cultured cucumber, soil microbial biomass, soil enzyme activity, phylogenetic tree, rhizobia, 16S rDNA, nifH, legume, Karst.