Study Of Site Specific Management Zone Based On Remote Sensing Image Of Farmland In The Phaeozem Area

The site-specific management zones(SSMZ)in farmland can guide field variable management,and it is an important way to realize the protection of cultivated land resources.The traditional SSMZ methods such as grid sampling,spatial interpolation and fuzzy clustering need a lot of sample data.It not only consumes a lot of manpower and material resources but also poor timeliness.How to use the advantage of remote sensing technique to realize SSMZ rapidly and accurately has become a new research focus.In this paper,two large scale fields respectively in Hongxing farm and Hailun cooperative in the black soil region of Northeast China were selected as study areas.We obtained different periods and different resolution remote sensing images of bare soil in Hongxing farm in 2015 as the data source,to develop an object-oriented segmentation method for delineation of site-specific management zones(SSMZ)based on remote-sensing imagery.And then we analyzed and validated SSMZ results and accuracy of different resolution image SSMZ results with sampling data,the normalized difference vegetation index(NDVI).We obtained soybean dry biomass,soybean yield and NDVI of August 13,2016 and built a linear relations between dry biomass,soybean yield and NDVI.This proved the feasibility of using NDVI for SSMZ delineation.The NDVI of remote sensing images in different growth periods in2011-2016 were selected as the data sources.We delineated the SSMZ of different crop growth in a field over years,and then analyzed the effect of topographic factors on SSMZ by using the trend of soil temperature,humidity,soil nitrogen content and NDVI in different slope and different time.The results of the study indicated that: 1)in the Phaeozem area,northeastern China,the fields are larger and includes plain and hillock regions.In the same field,soil nutrient and crop growth have significant spatial difference,which is suitable for the development of precision agriculture;2)the SSMZ results based on double bare soil image is better than that based on single image,and the SSMZ results based on 1 meters resolution image is better than that based on 4 meters,16 meters,30 meters resolution images.SSMZs derived from remote sensing images and the object-oriented segmentation method enhanced the difference of soil nutrient and NDVI between SSMZs and the homogeneity within SSMZs.3)the SSMZ results based on NDVI of Hailun cooperative form 2011 to 2016 indicate that SSMZ patterns were banded mainly affected by different farming practices before the cooperative was founded and SSMZ patterns show a different changing trend mainly affected by terrain,slope,and other factors after the cooperative was founded.4)In the Phaeozem area of Northeast China,due to the influence of undulating terrain,the trend of soil nutrientcontent,soil temperature and humidity between different slope have different pattern.Topographic factors indirectly determines the SSMZ by affecting crop growth and transport of water and fertilizer.In summary,the methodology developed in this study provides a rapid,accurate,and low-cost approach for SSMZ delineation and will accelerate the application of precision agriculture in the topographic relief area.The study of the effects of topographic factors on the SSMZ can provide guidance and reference for better research on SSMZ.The study results are conducive to promoting the development of precision agriculture in Phaeozem area of Northeast China,is of great significance for the protection of cultivated land quality and achieve the goal of sustainable development.