Research On Maize Precision Fertilization System Based On Multi-source Data

Maize is an important food crop in China and its food production is related to our food security and economic and social development.In recent years,China’s grain production has been increasing and the amount of chemical fertiliser applied has also increased year on year,thus leading to a serious problem of over-fertilisation.Excessive fertiliser inputs can lead to reduced crop resistance,lower quality and soil moisture pollution,while also increasing farmers’ cultivation costs and reducing economic benefits,seriously threatening the sustainable and healthy development of China’s agricultural production.How to improve the efficiency of fertiliser use,ensure the steady improvement of food production and quality,and achieve the efficient use of China’s soil and water resources,is of great significance to China’s successive promotion of sustainable agricultural development.Precision fertiliser application technology integrates traditional agricultural production methods with modern high technology and can effectively increase crop yields,improve soil quality,enhance planting efficiency and ensure stable improvement in grain yield and quality.Based on the spatial variability of the soil and crop growth characteristics within different cultivated plots,precision fertilisation technology divides the whole plot into management units with independent characteristics,increasing the homogeneity of soil nutrients and crop growth within each independent unit and increasing the heterogeneity of soil nutrients and crop growth between each independent unit,setting the precise amount of fertilisation according to the differences in the properties within different fertilisation units and carrying out precision fertilisation Management.In order to promote the precise and intelligent development of China’s agriculture,further improve the efficiency of agricultural production management and reduce surface source pollution.There is an urgent need to analyse the spatial and temporal differences in crop growth in the light of the actual situation of agricultural production in China,conduct research on precision fertilisation at the field scale according to the law of crop fertilisation requirements,and design an alternative,highly popular and functionally rich precision fertilisation system.In this paper,an experimental study was carried out at Youyi Farm,Shuangyashan City,Heilongjiang Province,and the study area was managed for precision fertilizer application by acquiring multi-source data from the sky and the earth including satellite remote sensing data,UAV multispectral data,UAV RTK data and ground sampling data.The method of accurate fertilizer application for maize base fertilizer: using the satellite images during the bare soil period for many years as the data source,combined with the object-oriented multi-scale segmentation algorithm,the research area is zoned for accurate management;and soil samples are collected during the bare soil period to obtain soil organic matter(SOM)and evaluate the zoning effect;based on the results of accurate management zoning,the accurate fertilizer application prescription map for maize base fertilizer is generated to guide the application of maize base fertilizer.The method of accurate fertilizer application for maize fertilizer: the Normalized Difference Vegetation Index(NDVI)was calculated from the UAV multispectral images of maize at the trumpet stage,combined with the topographic factors including elevation,slope,topographic relief and surface roughness as the data source,and the object-oriented multiscale segmentation algorithm was used to The results of this study were used to evaluate the effectiveness of the partitioning by using SOM data and NDVI;to generate a precise fertilizer application prescription map based on the results of the precise management partitioning to guide the application of fertilizer to maize;and to develop a precise fertilizer application system by combining the above findings.The main research findings are as follows:(1)At the field scale,under the same field management practices and without the influence of extreme weather,crop growth in the early stages of maize growth is stable and does not vary significantly from year to year.(2)In the early stage of maize growth,crop growth is affected by different topographic factors,and different topographic factors have different effects on crop growth in the early stage of growth.(3)Based on the multi-year bare soil period satellite images as the input quantity of precision management zoning,the precision management zoning method using object-oriented multi-scale segmentation algorithm is highly accurate;the coefficient of variation of SOM within each zoning unit after zoning is 0.04,which is at a weak degree of variation;the coefficient of variation of SOM between each zoning unit is 0.46,which is at a medium degree of variation;it effectively enhances the homogeneity of SOM within each zoning unit and the heterogeneity of SOM between each zoning unit.The coefficient of variation of SOM among the zonal units was 0.46,which was at a medium level of variation.The NDVI was calculated based on the UAV multispectral images of maize at the trumpet stage,and combined with the topographic factors including elevation,slope,topographic relief and surface roughness as the input of precision management zoning,and the precision management zoning method was highly accurate using the object-oriented multi-scale segmentation algorithm.The coefficients of variation of NDVI and SOM within each zoning unit are 0.01 and 0.03 respectively,which are both at a weak level of variation;the coefficients of variation of NDVI and SOM between zoning units are 0.20 and 0.31 respectively,which are both at a moderate level of variation;the homogeneity of NDVI and SOM within each zoning unit and the heterogeneity between zoning units are effectively enhanced,which can The coefficients of variation of NDVI and SOM within each zonal unit and the heterogeneity between zonal units were effectively enhanced,which could effectively guide maize fertilization.(4)The maize precision fertiliser system was studied experimentally in the study area and the results showed that the mean yield increased by 5.8%-13.2%,the standard deviation decreased by 8.4%-20.4% and the coefficient of variation decreased by 13.3%-31.8% under the precision fertiliser pattern;the precision fertiliser technique could significantly reduce the variability of maize yield in different terrains under the same treatment and improve maize yield.