The Growth Promotion of Peppers ( L.) by NJAU4742-Based Biological Organic Fertilizer: Possible Role of Increasing Nutrient Availabilities.

spp. is a cosmopolitan group of soil fungi which plays a remarkable role in stimulating plant growth after interacting with plant roots and has good application prospects in intensive agriculture. In this study, rice straw and amino acids improved the population of NJAU4742 under solid-state fermentation and helped us develop a new type of organic fertilizer. The effects of this biological organic fertilizer were evaluated in the growth of peppers ( L.) for two seasons under sandy and mountain soils. In the first season, the yields in T6 (0.06% solid fermentation products in soil) and AT6 (added 0.06% solid fermentation products and 1% amino acid organic fertilizer in soil) treatments were increased by 41.8% and 52.3% in sandy soil and by 51.6% and 46.5% in mountain soil, respectively, compared with chemical fertilizer. During the second season, the same trend was obtained in both sandy and mountain soils. Soil peroxidase activity (125.2 μmol·g dw), urease activity (58.7 μmol·g dw) and invertase activity (13.11 mg·g dw) reached their highest levels in biological organic fertilizer compared to the treatments with chemical fertilizer and solid fermentation products. Redundancy analysis showed that crop yield was positively correlated with enzyme activities, soil organic carbon, total nitrogen, and available phosphorus. Thus, we demonstrated that NJAU4742-enriched biological organic fertilizer could accelerate the transformation of nutrients and promote pepper growth.