Precision agriculture and irrigation - Current US perspectives

Authors: Evett, Steven - Steve; O`Shaughnessy, Susan; ANDRADE, MANUEL - Orise Fellow; Colaizzi, Paul; Schomberg, Harry; Anderson, Martha; Kustas, William - Bill

Submitted to: ASABE Annual International Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/2018
Publication Date: 8/1/2018
Citation: Evett, S.R., Oshaughnessy, S.A., Andrade, M.A., Colaizzi, P.D., Schomberg, H.H., Anderson, M.C., Kustas, W.P. 2018. Precision agriculture and irrigation - Current US perspectives [abstract]. ASABE Annual International Meeting. Paper No. 1801789.

Interpretive Summary:

Technical Abstract: Precision agriculture for irrigation is a relatively new aspect of precision agriculture (PA). Precision agriculture as a conceptual framework for farming operations responds to the need to manage inter-field and intra-field variability on farms, within watersheds, regionally and internationally. How PA is used, the objectives involved, and the technologies that support it have changed substantially. Since the inception of the U.S. Global Positioning System (GPS) becoming available for public use in the 1980s, it has been joined by geographical positioning systems run by China, the European Union and Russia. Coupled with geographical information system (GIS) computer technologies that were first developed for satellite imagery, PA became a mainstream tool for farmers to plan site-specific agricultural operations, now including site-specific irrigation. Equipment with GPS steering and position-aware supervisory control systems allowed pre-determined site-specific prescription maps to be downloaded into equipment and used, for example, to turn off a spraying system as it passed over a waterway. Today, similar prescription maps can be developed for precision irrigation using variable rate irrigation (VRI) center pivot or linear sprinkler systems, and even precision-enabled drip irrigation systems. Lack of adequate decision support systems (DSS) to drive VRI is a problem that is being resolved at both field-scale and larger (irrigation district and basin) scales. The VRI DSS in existence are based variously on soil spatiotemporal properties, including bulk electrical conductivity and soil water content, as well as on plant spatiotemporal properties such as canopy temperature, crop water stress index, cover fraction and normalized difference vegetation index (NDVI). These operate using data from one or more of multiple sources: satellites, such as Landsat and SMAP, aerial imaging systems including hyperspectral imaging, sensors placed on moving irrigation systems, and sensors mounted on tractors and other machines moving in the field. Spatially variable irrigation management now can be accomplished using 30-m resolution maps of crop water use based on multi-satellite sensor fusion. Many of the more successful PA technologies involve on-board sensor systems that feed data to embedded computing platforms that make on-the-fly adjustments to equipment. Such active and direct PA systems use modern technology that provides the ability, for instance, turn on variable rate irrigation nozzles where biotic stress sensors indicate crop water stress. Such supervisory control and data acquisition (SCADA) systems rely on algorithms based on sophisticated understanding of biophysics and biological systems. Today the confluence of computing power, data acquisition and management infrastructure, new modeling paradigms, and spatial decision support systems ushers in new possibilities for PA. Providers of PA services now include government institutions from national to local levels, private providers (often using publically available data from government ground, aerial and satellite sensing systems), university extension systems and farmer cooperatives. Sources of data range from public domain to private data held by farmers or third parties. Questions around data standards, data sharing, data ownership, and public and private rights add further complexity to modern PA, but are actively being addressed by both public and private institutions.