Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 9/6/2012
Publication Date: 8/1/2013
Publication URL: http://www.ars.usda.gov/SP2UserFiles/Place/53102000/pdf_pubs/P2391.pdf
Citation: Corwin, D.L. 2013. Site-specific management and delineating management zones. In: Oliver, M. editor. Precision Agriculture for Food Security and Environmental Protection. London, UK: Earthscan. p. 135-157. Interpretive Summary: Crop yield varies within fields due to nonuniformity of a number of factors including climate, pests, disease, management, topography, and soil. Conventional farming manages a field uniformly; as a result, conventional farming tends to wastes resources and money, and tends to detrimentally impact the environment. One way of handling crop yield variability in a cost and resource effective manner is divide a field into management units based on the observed yield and soil variability so that each unit can be treated similarly in order to optimize yield, resource utilization, and profitability, and minimize detrimental environmental impacts. These site-specific management units or SSMUs are a key component of precision agriculture. It is the objective of this book chapter to provide a general discussion of the methodology for delineating SSMUs using geophysical techniques. The approach uses spatial measurements of electrical conductivity to locate where soil samples are to be taken to characterize the variability of soil properties influencing the variation of crop yield within a field. Maps of the SSMUs are created that provide a producer with information for variable-rate technology (e.g., site-specific fertilizer and irrigation water application).
Technical Abstract: Precision agriculture has been envisioned by futurists for decades. The first Landsat satellite in 1972 caught the public’s eye because it was sold as a technological tool for monitoring and managing natural resources, which was viewed as a potential stepping stone for precision agriculture. Whether satellite imagery of the Earth was oversold to the public or the public’s expectations were too high, it would take another two decades before the necessary technological tools were in place to be able to obtain the spatial information necessary to support precision agriculture and even longer for scientific knowledge to catch up with technology. We are now at a turning point in our knowledge and understanding where precision agriculture will be a mainstream practice. Even though conventional agriculture has served humankind well, its limitations are more and more evident as the world’s food producers push production to the limit with finite resources and a close eye on the environmental ramifications of their efforts. Because conventional agriculture ignores the spatial and temporal complexity of the interacting factors influencing crop yield and focuses on productivity, it will not be able to meet the global economic, environmental and limited-resource challenges of the future. Barring any new technological breakthroughs, precision agriculture, or more specifically, site-specific crop management is the next logical step to meeting world food demands using state-of-the-art scientific knowledge and technology that can address these spatial and temporal complexities. It is the objective of this book chapter to describe the methodology for delineating the fundamental management unit of precision agriculture, i.e., site-specific management units (SSMUs), and how these benefit producers to achieve sustainable agriculture.