Spatial And Temporal Variation Of Soil Nutrients And Its Influencing Factors In Grain Yield Project Area In Hebei Province Based On GIS

The special project of “High-efficiency grain production and scientific and technological innovation” in Hebei Province is a national key project.The implementation of this project has improved the grain output of Hebei Province and promoted the industrialization of grain production.Soil nutrients can directly affect the level of grain yield,with certain dynamic variability and spatial heterogeneity.Different soil nutrient values are the basis of scientific fertilization.Therefore,this paper explores the variation law and influencing factors of soil nutrients in the grain high-yield project area of Hebei Province from the two dimensions of time and space,in order to provide scientific basis for improving grain yield and guiding soil testing and formula fertilization,and ensure the stable increase of grain production.This paper takes the ploughed soil as the research object in the grain high-yield project area of Hebei Province(the piedmont plain,the northeastern part of Heilongjiang Plain,the central and southern Heilongjiang Plain,and the Yanshan Mountain Plain),and selects the main ones in 2008 and 2018.Soil nutrient organic matter,available phosphorus,available potassium and slow-acting potassium index,using ArcGIS technology and geostatistics method to analyze the spatial and temporal variation characteristics of soil nutrients in 2008 and 2018,and explore the soil from natural and socio-economic factors.The impact of nutrient changes.The main results are as follows:(1)In terms of space,the four soil nutrients in the study area were all moderately variable,and the variability was significant.The Kriging method was used to interpolate the soil nutrient space.It can be seen that organic matter and slow-acting potassium have similar spatial variability trends,which are presented as a whole.The trend of decreasing west to east,the high value area is mainly distributed in the south-central part of the piedmont plain and the southern part of the Yanshan foothill plain;the available phosphorus shows a high content in the northeast and southwest,and a low content in the middle.The high value area is mainly distributed in the piedmont plain.In the southern part of the Yanshan foothill plain,the available potassium decreased from east to west,and the high value area was mainly distributed in the northeast of Heilongjiang Plain and the southern part of Yanshan Mountain Plain.(2)In terms of time,the average values of soil nutrients increased in 2008 and 2018.In the 10 years,the soil nutrient grades in the central part of the study area increased significantly,including the central plain of the piedmont,the Heilongjiang Plain,and the south and south of the Yanshan Mountains.The soil nutrient grade is relatively small due to human activities,and the change is not obvious,including the Lingshou and Xingtang in the western plain of the piedmont,the scorpion in the southern part of the Heilongjiang Plain and the west of the Yanshan Mountain Plain.Through the change of the soil nutrient levels,it is concluded that the soil nutrient grades have increased in the past 10 years,and the organic matter and available phosphorus have increased significantly.(3)The change of soil nutrients in cultivated land is affected by natural factors.Correlation analysis shows that there is a significant correlation between annual average temperature and soil nutrient.However,since the plain area is mostly agricultural land,human factors have become the main factors affecting soil nutrient variation.In the production process,the application rate of agricultural chemical fertilizers is on the rise,but the amount of fertilizers is still kept at a certain amount.The pesticide application rate of farmers is decreasing,the fertilization structure is balanced,the fertilization management is scientific and rational,and the soil structure of farming is improved,affecting soil nutrient content.The multiple cropping index showed a downward trend.The number of crops reduced by farmers was conducive to maintaining the combination of cultivated land and promoting the accumulation of soil nutrients.Changes in crop planting structure will affect the input of materials and the absorption of nutrients by different crops,thus changing the soil nutrients of cultivated land.Therefore,human activities can greatly affect the variation of soil nutrients,which in turn affects the yield of food.