模拟侵蚀、施肥和采样时间对东北黑土区土壤性质和质量的影响OA

[Objective]Soil erosion is one of the major causes of soil degradation and land productivity deterioration in the black soil region of northeast China,and fertilization is a primary measure to improve soil fertility and productivity.The combined effects of simulated erosion,fertilization,and sampling time on soil properties and quality remain unclear.Based on an 18-year long-term simulated erosion experiment,this study investigates the main effects and interactions of simulated erosion intensity,fertilization,and different sampling times during the maize growth stages on soil properties and quality.[Methods]The experiment included two factors:simulated erosion intensity and fertilization.Simulated erosion intensity was set at eight gradients,corresponding to erosion depths of 0,10,20,30,40,50,60,and 70 cm.Fertilization treatments included no fertilization and fertilization according to local field practice.The experiment was conducted using a completely randomized block design.Thirteen surface soil properties were measured at different maize growth stages:gravimetric water content,pH,organic carbon,alkali-hydrolyzable nitrogen,available phosphorus,available potassium,microbial biomass carbon,nitrogen,and phosphorus,as well as the activities of urease,catalase,β-glucosidase,and cellulase.[Results]With increasing simulated erosion intensity,organic carbon,alkali-hydrolyzable nitrogen,microbial biomass carbon,nitrogen,phosphorus,urease,β-glucosidase,and cellulase activities significantly decreased.The available potassium content significantly increased,and catalase activity showed a ＂U＂-shaped trend.Fertilization significantly increased organic carbon,alkali-hydrolyzable nitrogen,available phosphorus,microbial biomass phosphorus,urease,and cellulase activities,while significantly decreasing pH,available potassium,and catalase activity.Sampling time significantly affected 12 soil properties,and seasonal variation patterns differed among soil properties.There were few or no interactions between simulated erosion and other factors,but fertilization and season exhibited significant interactions for 8 out of 13 soil properties.Simulated erosion significantly reduced the soil quality index,with most of the decline occurring before 30 cm of erosion depth.Fertilization increased the soil quality index by 12%,with the highest value observed in September and the lowest value in August.[Conclusion]The findings clarify the main effects and interaction effects of simulated erosion intensity,fertilization,and sampling time on soil properties and quality,providing guidance for dynamic assessment and remediation of black soil degradation.