Effects of Different Green Manure Varieties and Sowing Times on the Growth,Soil Enzyme Activity,and Microbial Diversity of Chili Pepper in Guizhou

YAO Danjun; LIAO Heng; ZHANG Qin; KUANG Shengjian; LIANG Yanfei; ZHANG Aihua; QIN Song; ZHU Qing

doi:10.15933/j.cnki.1004-3268.2025.09.010

Abstract：To investigate the effects of different types of green manure and sowing time on the growth,yield,quality,soil enzyme activity,and microbial diversity of Guizhou chili peppers,the Zhengjiao No.6 chili pepper was used as the material,and 11 treatments were set up,including winter fallow,winter planting of cabbage,and sowing of different green manures(Vicia villosa Rothvar,Vicia sativa L.,Brassica campestris)at different times(late August,mid to late September,mid October).The growth indicators,nutrient accumulation,yield,quality,soil enzyme activity,microbial diversity,and other indicators of chili peppers were measured.The results showed that the type of green manure and the time of sowing had varying degrees of impact on the yield and nutrient accumulation of green manure.Various green manure planting treatments slowed down the decrease in chlorophyll relative content in the leaves of chili peppers in the later stage of growth,with the most significant effect observed in the sowing treatment of Brassica campestris at the end of August.During the harvesting period of chili peppers(114 days after transplantation),the above ground dry matter mass and nitrogen,phosphorus,and potassium accumulation of chili peppers treated with Brassica campestris at the end of August increased by 39.45%,64.46%,45.50%,and 31.95%,respectively,compared to the winter idle treatment.The highest yield of chili pepper was achieved by sowing Vicia sativa L.at the end of August,which increased by 5.56%compared to winter fallow.The sowing treatment of Brassica campestris at the end of August,increased the vitamin C and reducing sugar content of chili peppers by 20.69%and 0.18%respectively compared to the winter idle treatment,while reducing the nitrate content by 10.78%.Planting green manure significantly increased the activities of soil urease,sucrase,and catalase,with soil urease activity increasing by 15.94%to 89.18%compared to cabbage treatment and 10.26%to 79.91%compared to winter fallow treatment.Planting green manure could effectively improve soil microbial diversity,and the Ace,Chao,and Sobs indices of bacterial and fungal communities were most significantly increased by sowing Brassica campestris at the end of August.The correlation analysis between soil enzyme activity,bacterial community diversity,fungal community diversity,and chili growth,yield,and quality indicators showed that green manure affected chili fruit yield and quality by increasing soil microbial community diversity and enzyme activity.In summary,planting green manure in winter and returning it to the field can enhance soil enzyme activity and microbial diversity,promote the growth of Guizhou pepper,improve pepper yield and quality.Among different types of green manure,Brassica campestris has the best effect,and its optimal sowing time is at the end of August.