Effects Of Different Planting Methods On Soil Enzyme Activities And Soil Microbial Biomass And Diversity

Aiming at the problems of soil poor desertification and decrease of soil effective nutrients in the agropastoral region of North foot of Yinshan Mountain,in order to improve the environment and soil equality,with alfalfa,Elymus sibiricus L.and forage oat as materials,four different planting patterns except the control were conducted using field experiments: Single-seeding alfalfa,Single-seeding Elymus sibiricus L.,Single-seeding forage oat and Intercropping,with leisure treatment as control check.Through the analysis of soil enzyme activity,microbial biomass and microbial diversity,the results were as follows:(1)The activities of four enzymes were significantly affected by different forage planting methods.The activity of four enzymes in each treatment was higher than that of control,and the urease activity of intercropping was the highest.With the development of forage growth period,catalase and alkaline phosphatase activities continued to rise,urease activity showed an increase trend of increasing first and then slowly decreased,sucrase activity showed a trend of decreasing first and then increasing.In addition,the enzyme activity after final harvest was higher than that of before sowing.With the increase of soil depth,the activities of hydrogen peroxideand alkaline phosphatase gradually decreased,but the activities of urease and invertase increased first and decreased then.(2)The microbial biomass carbon and phosphorus were increased by various forage planting methods.The microbial biomass carbon level of control was3.4%~14.1% higher than that of other treatments.The microbial biomass nitrogen content of intercropping treatment was 15.8%~18.6% higher than that of other treatments.The microbial biomass nitrogen content of mixed and unisown alfalfa was higher than that of other treatments.The total microbial biomass nitrogen content was lower after harvest than that of before sowing.The content of microbial biomass phosphorus of leisure was 1.1%~15.9% higher than that of other treatments.(3)With the development of pasture growth period,the bacterial Alpha diversity index showed an upward trend,the fungi showed a downward trend,and the arbuscular bacteria did not change significantly.Comparison of ? diversity found that planting methods are the main factors affecting bacteria and arbuscular bacteria,and sampling time is the main factor affecting fungi.From the community composition,the dominant of bacteria was Proteus and Actinomycetes;the dominant of fungi was Ascomycota;the dominant of arbuscular bacteria was Glomus.In summary,intercropping is more conducive to improving soil enzyme activity,microbial biomass and enriching soil microbial diversity,thereby promoting the enrichment of soil nutrients,which is of great significance to maintaining the balance of soil ecosystem.