Characteristics And Analysis Of Enzyme Activities And Nutrients In Different Soil Types In Hailun Cit

Soil enzyme activity plays a crucial role in the decomposition and mineralization of soil organic matter and the overall maintenance of nutrient cycles such as nitrogen and phosphorus,for this reason,the content of soil nutrients goes hand in hand with soil enzyme activities.To reveal the spatial characteristics of soil enzyme activities and nutrients in farmland at regional scale,and clarify the potential relationship between soil nutrient factors and soil enzyme activities.Based on the field investigation,grid sampling and laboratory analysis,this study took the farmland of Hailun City as the research area,black soil,meadow soil and dark brown soil in farmland soil of Helen were taken as research objects,and made clear the differences of nutrients content and enzyme activitis of different soil types by using the principle of mathematical statistics.Path,string and other methods were used to expound the internal connecting link between soil nutrients and soil enzyme activities.According to the spatial analysis principle of geostatistics GIS,the spatial distributions and structural properties of soil enzyme activities and soil nutrients in farmland of Hailun City were explored.The main results were as follows:(1)The p H of dark brown soil was significantly higher than that of meadow soil and black soil(p < 0.05).Compared with meadow soil and black soil,the contents of soil organic carbon and total nitrogen in dark brown soil were significantly higher(p < 0.05).There was no difference in soil cellulase,urease and phosphatase activities among dark brown soil,meadow soil and black soil,and only the invertase activity of dark brown soil was significantly higher than that of meadow soil and black soil(p < 0.05).Farmland p H in Hailun City had weak variation,while the contents of soil organic carbon,total nitrogen,total phosphorus and soil cellulase activity had medium variation.And soil phosphatase,urease and sucrase activities had strong variation.Among different soil types,soil urease activity of black soil was significantly positively correlated with soil organic carbon and total phosphorus content(p < 0.05),and soil phosphatase activity was significantly positively correlated with total nitrogen content(p < 0.05);in dark brown soil,there was significant positive correlation between urease activity and TP(p < 0.05),and between phosphatase activity and soil organic carbon,total nitrogen(p < 0.05);the activities of four soil enzymes in meadow soil were significantly positively correlated with soil ogranic carbon and total nitrogen(p < 0.05),while total phosphorus was only significantly positively correlated with soil phosphatase and urease activities(p < 0.05).(2)The spatial analysis showed that the spatial correlations of soil p H,soil cellulase,urease and phosphatase activities in farmland of Hailun City were weak,mainly affected by agricultural activities and agricultural management measures and other random factors.Soil ogranic carbon,total nitrogen,total phosphorus and soil sucrase activities were all moderately correlated,which were mainly affected by physical and geographical factors and random factors.The p H in the northeast of Hailun City was obviously lower than that in the southwest,but the activities of soil organic carbon,total nitrogen,total phosphorus and four soil enzymes in the northeast were obviously higher than those in the southwest,and the contents basically showed a low-high-low-high trend from the southwest to the northeast,mainly distributed in blocks.(3)In the farmland soil of Hailun City,there was a significant positive correlation among soil organic carbon,total nitrogen and total phosphorus(p < 0.01),the activities of soil cellulase,phosphatase,urease and sucrase were positively correlated with soil organic carbon,total nitrogen and total phosphorus(p < 0.05),and the activities of the four enzymes were also positively correlated(p < 0.01).The p H was negatively correlated with soil organic carbon and the activities of soil cellulase(p < 0.05),meanwhile,was negatively correlated with the activities of soil phosphatase and sucrase(p < 0.01).Soil phosphatase activity and soil organic carbon were the environmental factors that directly affect soil cellulase activity,and soil total nitrogen content indirectly affected soil cellulase activity.Soil urease activity was mainly affected by soil phosphatase activity directly and indirectly by soil total nitrogen.Soil phosphatase activity was not only directly related to soil urease activity but also indirectly affected by soil organic carbon content,soil invertase activity and soil total phosphorus content.Soil sucrase activity was directly affected by soil cellulase activity and soil organic carbon content,and indirectly affected by soil phosphatase activity and soil total nitrogen content.