Submitted to: Remote Sensing Reviews
Publication Type: Abstract only
Publication Acceptance Date: 2/8/2005
Publication Date: 2/8/2005
Citation: Sullivan, D.G., Truman, C.C., Rowland, D., Faircloth, W.H., Bosch, D.D. 2005. Measuring the soil-plant-water continuum: tillage and irrigation impacts. In:Proceedings of A State-of-theArt Review of Evapotranspiration (ET). Remote Sensing Science and Technology Workshop, February 8-10, 2005, USDA-ARS Natural Resources Research Center, Colorado State Univ., Ft. Collins, Colorado. Interpretive Summary: Crop production in the Coastal Plain is generally water-limiting. Soils have been intensively cropped (cotton, peanuts), tend to be drought-prone, and susceptible to erosion. Rainfall in this region (~ 50 inches per year) is poorly distributed, and producers commonly utilize supplemental irrigation to sustain crops during extended dry periods. A major problem facing producers in the region is maintaining crop yields, maximizing current water resources through efficient water use, while addressing soil and water quality concerns associated with sediment and agrichemical losses to off-site areas. Proper on-farm water management, especially irrigation scheduling, is critical to sustaining Coastal Plain farmers in the future. High fuel prices coupled with high production costs and low commodity prices require improved management of on-farm resources to improve profit margins and net returns to producers of this region. Surface residue management coupled with conservation tillage in the form of strip tillage is a viable management tool for producers in the Coastal Plain region of Georgia. Strip tillage and residue cover improves soil quality, promotes infiltration, increases soil and plant available water, and reduces runoff and erosion. Results presented at this workshop help producers maximize water use efficiency by reducing the amount of irrigation needed for sustaining crop production; thus increasing a producer's profit margin and net returns, while maintaining water supplies and minimizing off-site environmental contamination.
Technical Abstract: Competition among crop producers, municipalities, and industry for water resources in the South Atlantic Coastal Plain necessitates innovative tools for streamlining water resource management. To address these issues an interdisciplinary and collaborative research team has been established at the USDA ARS Southeast Watershed and National Peanut Research Laboratories. Research emphasizes a primary row crop rotational system utilized by farmers in the southeastern U.S. and includes cotton and peanut rotations with one to two-year duration of a single crop type. Two long term study sites have been established in Southwest Georgia. Soils consist of Tifton loamy sand (Plinthic Kandiudult) at site one and Greenville sandy loam (Rhodic Kandiudult) at site two. Soils represent two of the most predominant soil series in the South Atlantic Coastal Plain physiographic region. At both sites, the impact of conventional and strip tillage systems on hydrology and plant available water are being evaluated. Data indicate that strip tillage improves infiltration and increases plant available water content over time. Preliminary assessments of yield and crop water use also show that strip tillage can reduce the amount of irrigation required to obtain optimal yields. During the 2004 growing season, remotely sensed data collected via a handheld spectroradiometer (visible and near infrared) and thermal imager (thermal infrared) was added to evaluate real time methods of measuring crop water demand. Data are promising and indicate that remotely sensed estimates of crop water demand may be useful for within season management of irrigation needs.