Submitted to: ESRI Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: July 1, 2005
Publication Date: July 24, 2005
Citation: Corwin, D.L. 2005. Delineating site-specific crop management units: Precision agriculture application in GIS. In: Proceedings of 2005 ESRI International Users Conference. July 25-29, 2005. San Diego, California. 2005 CD-ROM. Paper No. UC1184 Interpretive Summary: Conventional agriculture treats an entire field uniformly. However, soil is spatially heterogeneous, with most soil chemical and physical properties varying significantly within just a meter. Soil spatial heterogeneity is one of several factors that cause within-field variation in crop yield. Other spatially and/or temporally variable factors influencing within-field variation in crop yield include man-related (e.g., irrigation management, compaction due to equipment, etc.), biological (e.g., disease, pests, etc.), meteorological (e.g., humidity, rainfall, wind, etc.), and topographical (e.g., slope, aspect, etc.) influences. The inability of conventional farming to address within-field variations in these factors not only has a detrimental economic impact due to reduced yield in certain areas of a field, but also detrimentally impacts the environment due to over applications of agrochemicals and wastes finite resources. Precision agriculture, or more appropriately site-specific crop management, has been proposed as a means of managing the spatial variability of edaphic (i.e., soil related), anthropogenic, topographical, biological, and meteorological factors that influence crop yield with the aim of increasing profitability, increasing crop productivity, sustaining the soil-plant environment, optimizing inputs, and/or minimizing detrimental environmental impacts. Site-specific management units (SSMUs) are spatial domains of soil that can be managed similarly to optimize yield by accounting for variability. A study is presented that demonstrates how SSMUs for a field of irrigated cotton can be established using GIS and other advanced information technologies, such as statistics, remote sensing, and crop-yield modeling.
Technical Abstract: Crop yield is influenced by soil-related, anthropogenic, topographic, biological, and meteorological factors that are highly spatially variable. Because of the complex spatial interaction of these factors, GIS and other advanced information technologies (e.g., spatial statistics, remote sensing, crop-yield response models) are essential tools in precision agriculture. Site-specific crop management refers to the application of precision agriculture to crop production. A fundamental aspect of site-specific crop management is the delineation of site-specific management units (SSMUs), which are spatial domains where soil properties can be managed similarly to optimize crop yield. In a study conducted by USDA-ARS scientists at the George E. Brown Jr. Salinity Laboratory, ArcView, electromagnetic induction, spatial statistics, and regression analysis were used to identify soil-related factors influencing crop (i.e., cotton) yield within an 80-acre field in California’s San Joaquin Valley. The developed maps and crop-yield response model provided the essential information for site-specific crop management recommendations.