Effects Of Intercropping Potatoes With Corn And Kidney Beans On Soil Environmental Factors And Microbial Diversity In The Southern Mountains Of Ningxia

Intercropping is a kind of planting method of intensive utilization of resources,which can alleviate the occurrence of soil//borne diseases caused by perennial continuous cropping,and plays an important role in improving soil environment and improving land use efficiency.In this experiment,potato intercropping maize and potato intercropping kidney bean were taken as the research objects.The response of rhizosphere soil environmental factors and soil bacteria and fungi to different cultivation methods was studied by random block design.The biomass and community structure of bacteria and fungi in intercropping soil were analyzed by molecular biology methods.The results showed that:(1)The intercropping system significantly improved the physical and chemical properties of the soil during each growth period.Compared with the monoculture treatment,the organic matter content was significantly increased by 8.21%//27.90%,and the content of large//pore water//stable aggregates in the soil was increased by 38.12%on average.Potato//kidney bean significantly increased the nitrogen level of the plough layer soil,and the available phosphorus content of potato//maize intercropping significantly increased by 29.09%//32.80%in the late growth stage.(2)Intercropping cultivation improved the activities of β//glucosidase,N//acetylglucosaminidase and cellobiohydrolase related to C and N cycles in the mountainous area of southern Ningxia,and shortened the cycle of soil nutrient cycle.Soil organic matter content was significantly positively correlated with glucosidase and N//acetylglucosaminidase.Soil macropore aggregates were positively correlated with alkaline phosphatase,and glucosidase activity was positively correlated with N//acetylglucosaminidase activity.(3)Intercropping treatment increased the soil water content of the tillage layer in each growth period,and decreased the water content of the 60//100cm deep soil,which proved that intercropping cultivation could make plants use the deeper soil water,and the change trend of soil moisture in different soil layers during the growth period was first increased and then decreased.(4)Potato//kidney bean intercropping treatment can significantly increase the number of large and medium potatoes,reduce the rate of small potatoes,effectively increase the yield of potatoes,and increase the commodity rate of potatoes;the yield of potato//maize intercropping treatment was higher than that of monoculture potato,but the difference was not significant.(5)The bacterial sequencing results of soil samples showed that a total of 46644 OTUs of soil bacteria were obtained.There was no significant difference in Shannon index and Simpson index between treatments,indicating that the richness and diversity of soil bacterial communities were not sensitive to tillage methods.At the phylum level,Actinobacteria,Proteobacteria,Chloroflexi and Acidobacteria were the dominant species in each planting mode.The potato//maize intercropping acidobacteria was significantly higher than other treatments.The principal coordinate analysis of bacterial community showed that the composition of soil bacterial abundance was different under different tillage modes.Correlation analysis showed that cellobiohydrolase and soil nutrients were the main factors associated with the change of bacterial phylum abundance.The results of fungal sequencing of soil samples showed that 2333 OTUs of soil fungi were obtained.The soil fungal community richness index and Shannon index of potato//maize intercropping were the highest and significantly higher than those of monoculture treatment by 13.90%and 26.69%.Intercropping measures significantly increased soil fungal diversity.At the phylum level,Ascomycota and Mortierellomycota were the dominant phylum.Ascomycota in the potato//maize intercropping potato area was significantly higher than that in the monoculture treatment.The analysis of the left side of the soil fungal community showed that the abundance of soil bacterial phylum was different in different tillage patterns.Correlation analysis showed that glucosidase and soil nutrients(6)Potato//kidney bean 1:1 intercropping is suitable for improving land use efficiency in southern Ningxia mountainous area.