Research On Field Collection And Variation Of Precision Agriculture Based On GIS And Geostatistics

China is a relatively large agricultural country in the world.Since the 21st century,chemical fertilizers and pesticides have had a positive effect on China's agricultural production.At the same time,they have also had adverse effects on the ecological environment and human development.In recent years,precision agriculture has been rapidly developing in the country.The purpose of development is to reduce the negative impact of traditional agriculture.Precision fertilization is a major application area in precision agriculture.In this paper,the use of GIS and geostatistics to explore the spatial variation of cultivated land nutrients is an inevitable basis and prerequisite for the development of precision agriculture.At the same time,it provides a scientific basis for the implementation of precision agriculture.The research field in this paper is located in a cotton field in Erlian,Liufenchang,Shihezi Shishizi.Using GPS positioning,the sample was taken from a 20m×20m grid to study soil nutrient-alkali nitrogen,available potassium,and available phosphorus.Spatial Variation and Spatial Distribution of Nitrogen and Organic Matter.The results show:?1?For the average soil nutrient content,the highest potassium content was309.2778 mg/kg.The lowest total nitrogen content was 0.8267 g/kg.The remaining soil nutrient contents were 19.4917 kg of available phosphorus,70.6972 mg/kg of alkali-hydrolyzed nitrogen,and 11.7878 g/kg of organic matter.The available potassium is in the higher range,the available phosphorus is in the suitable range,and the total nitrogen,alkaline nitrogen and organic matter are in the low range.The largest coefficient of variation in soil nutrient content was total nitrogen,which was44%.Followed by followed by organic matter>alkaline nitrogen>available phosphorus>quick-acting potassium,of which the coefficient of variation of available potassium is a minimum of 9%,which is a weak variation,and the remaining soil nutrient content is a moderate variation.All test data are in normal distribution.?2?There are certain spatial correlations between soil nutrients at the sampling interval of 20m.The most variable is the available phosphorus,which is 91.91m,and the smallest is the total nitrogen,which is 39.10m.The order of magnitude of the remaining indicators is:alkaline nitrogen>available potassium>organic matter.The soil nutrient range of each soil was more than 20m,and the spatial autocorrelation distance was larger than the distance between the sampling points,indicating that the sampling scale of this study was within the reasonable range of the 20m“grid method”in this study.In some soil nutrients,available P 25%<C₀/?C₀+C?<75%,showing moderate spatial correlation,and the available K,organic matter,total nitrogen C0/?C0+C?>75%,expressed as Weak spatial correlation.?3?Choose the optimal theoretical model and Kriging method for spatial interpolation to obtain the spatial distribution map of soil nutrients.The results show that:The content of alkaline dissolved nitrogen in the study area is overall lacking.The areas with higher concentrations are concentrated in the north and east regions.The areas with lower concentrations are concentrated in the south and southwest regions,and the content is in the range of 50-60 mg/kg.The largest proportion is70.29%.The spatial distribution of organic matter as a whole is high in the middle,low in the north and south,and the organic content in the south and southwest is the lowest.The content of the area in the range of 10¹6g/kg is the largest,accounting for48.24%.Overall,according to national standards,the overall organic content is at a low level.The overall phosphorus content in the study area is suitable,and the spatial distribution of available phosphorus and alkali-hydrolyzed nitrogen are very similar.Both show a strip distribution from south to north.The areas with higher contents are in the north and northeast regions,and the areas with the lowest content are in the southwestern region.The area ofavailable phosphorus in the range of 17-20 mg/kg is 48.13%,and the area occupied is 4813m².The available potassium content in the entire study area is relatively high,and its spatial distribution pattern changes greatly,mainly in the form of spots and strips.The areas with higher levels are concentrated in the true north region.The areas with lower concentrations are concentrated in the southwest,south and central regions,and the spatial distribution is relatively different.The spatial correlation of available potassium is weak and it belongs to medium spatial correlation.The spatial phasing of available potassium was explained,and the spatial variability was influenced by random factors such as fertilization,field management,and planting density.The largest proportion of the study area was 61.6%in the range of 260-270 mg/kg.According to national standards,the total nitrogen at the test site is at a medium level,and total nitrogen appears striped from south to north.The area with the highest total nitrogen content in the study area is mainly concentrated in the north and northeast regions,and the content is greater than.The areas with the lowest content are mainly concentrated in the southwest and southern regions.The proportion of the study area in the range of 0.5¹g/kg is the largest,which is 60.97%.The content of more than 0.5g/kg accounts for 88.51%of the total area of the study area..?4?The plant height in the southern region was significantly lower than that in the northern region,and the plant height was also higher in the regions with higher contents of alkaline dissolved nitrogen,available phosphorus,available potassium,and total nitrogen.The content of organic matter in the central region of the experiment was the highest,but the height of the plant height in the central region of the test site was not the highest,which was about 85cm-95cm,and there was a gap relative to the plant height of about 100cm in the northeast.Explain the determinants of plant growth quality and determine only the level of soil nutrients.From the spatial interpolation of soil nutrient distribution and plant height overlay,the spatial distribution of plant height and the actual height of field measurements are still more different,which is due to the error of spatial interpolation.