Analysis On Soil Fertility Characteristics Of Agricultural Land In Lanzhou City

In this paper,the total nitrogen,available phosphorus,available potassium,organic matter and pH of the soil in the 0-20 cm cultivation layer of 919 agricultural lands in the study area were measured and analyzed.According to the relevant data,the geostatistics,entropy and AHP were used to analyze the soil nutrients in Lanzhou agricultural land The results of the analysis of the weight of each factor of the system composed of the inter characteristics and five kinds of nutrient elements lay a solid foundation for the evaluation of agricultural land in Lanzhou City,Gansu Province.In this study,the following achievements have been achieved:(1)Compared with the results of the long-term dynamic monitoring points of fertility in 2014 and the test and analysis of formula fertilization in recent three years in 2014,the five types of nutrients in the study area were slightly lower than that in the whole province.In this study,the contents of total nitrogen and available potassium were higher,and their average contents were 673.99mg/kg and201.40mg/kg The average content of available phosphorus is 35.59mg/kg The average content of organic matter is low,and the average content is 12.53g/kg.In this study,the soil pH value of the whole study area is Seven point five Above,the soil characteristic is alkaline soil.(2)There is a significant spatial correlation in spatial distribution of soil nutrients of agricultural land in Lanzhou City,Gansu Province.It can be seen from the global Moran index that the expected index of the five elements in the random mode has a strong spatial correlation in the spatial position of the adjacent sampling points.The distribution model of total nitrogen and pH is Gaussian model,the distribution model of available phosphorus and available potassium is exponential model,and the distribution model of organic matter is spherical model.It can be seen from the nugget coefficient that all the nugget coefficients of the five nutrient elements are Zero point five In the following,it shows that these five elements have strong spatial variability in space.(3)In the soil nutrient system of agricultural land in Lanzhou City,Gansu Province,which is composed of five kinds of soil nutrients: total nitrogen,availablephosphorus,available potassium,organic matter and pH,the weight of available potassium is the largest,ranking first,the organic matter is in the second place,the total nitrogen and available phosphorus are behind the organic matter,and the pH is less than 0.01,ranking last.