| Perennial continuous cropping of corn reduces the quality of soil fertility,which is the basis for crop growth.Therefore,studying the effects of different crops on the physical and chemical properties of continuous crop corn field has important guiding significance for improving soil fertility quality and rationally arranging crop layout.This study mainly analyzed the effects of different crops on soil physics,chemistry and enzyme activity traits,and comprehensively evaluated the soil fertility quality,in order to select the best crops,and provide a basis for scientific management of farmland and improvement of soil fertility quality.This experiment was set up in 2017 to systematically study the effects of planting sorghum(CSM),red kidney bean(CRK)and soybean(CSN)on soil fertility quality with continuous corn(CCN)as a control.The main findings are as follows:(1)Compared with CCN treatment,CRK treatment can reduce the soil bulk density of 0-30 cm profile and increase soil porosity.The soil bulk density of the soil in the 20-30 cm soil layer was significantly reduced by CSM and CSN treatment,and the total soil porosity was significantly increased.(2)The water-stable agglomerates of different treatments were mainly in the particle size of <0.25 mm,accounting for 65.92%-84.73%.The CRK treatment can increase the soil aggregate content of >5 mm particle size compared with other treatments,and can increase the soil average weight diameter(MWD)and geometric mean diameter(GMD)of 0-5 cm and 10-20 cm soil layers,and reduce the soil fractal dimension PSD value.(3)Compared with CCN treatment,CRK treatment can increase soil available phosphorus content,soil organic carbon content,soil particle fraction and soil particulate organic carbon content.The CSN treatment can increase the alkali nitrogen content(61.60 mg/kg)and organic carbon storage(6.60 T/hm2)in the 0-5 cm soil layer and increase the proportion of soil particles in the 10-40 cm soil layer.(4)For soil enzyme activity,CRK increased soil urease activity by 0-30 cm compared with CCN treatment,while CSN and CSM treatment increased soil invertase activity(28.86%)and catalase activity(18.39%),respectively.The comprehensive analysis of soil fertility quality showed that the comprehensive index of soil fertility quality treated by CRK and CSN was 57.69 and 57.58,respectively,which was significantly higher than that of CCN and CSM.It has been shown that CRK treatment can improve the soil physical and chemical properties of continuous cropping corn field,increase soil urease activity,and have a good effect on improving soil fertility quality.It can be used as the first crop for cropping short-term soil improvement in corn field. |
