不同类型作物根系对黑土物理特性和根际土壤性质的影响OACSTPCD

In order to study the influence of different types of plant roots on rhizosphere soil and bulk soil properties,we carried out a 51-day pot experiment to investigate soil physical properties,nutrient status and microbial biomass carbon at different growth stages of six crops,including rape,welsh onion,pepper,wheat,corn and soybean.Moreover,the relationships of crop root character-istics with selected soil physiochemical properties and microbial biomass carbon in the rhizosphere soil were analyzed.The results showed that with the crop development,the bulk density reduced,while the saturated water content and maximum field capacity of the rhizosphere soil increased.The three-phase structure of the soil was improved.Among crops,welsh onion exhibited the best three-phase structure of the rhizosphere soil.Compared with the initial soil properties,the soil organic carbon and total nitrogen in the rhizosphere increased by 0.9%-3.2%and 1.0%-15.0%respectively after 51-day sowing.Pepper had the highest organic carbon concentration and soybean had the highest total nitrogen content in the rhizosphere soil.Correlation analysis showed that crop biomass was positively correlated with soil total nitrogen and soil microbial biomass carbon,and negatively correlated with soil carbon to nitrogen ratio,saturated water content and maximum field water holding capacity.Principal component analysis showed that PC1 and PC2 explained 26.0%and 22.9%of the variation in soil properties;the crop biomass was different among crops;and the difference between soil saturated water content and maximum field water holding capacity at different growth stages was significant.In summary,welsh onion is the optimal crop in improving soil physical properties of rhizosphere soil,while soybean is the most efficient crop in increasing soil organic carbon and total nitrogen due to root exudates.