• H.C. Pringle - Asst. Agricultural Engineer, DREC, Mississippi State University, Stoneville, MS
• Dr. G.F. Sassenrath-Cole - Plant Physiologist, USDA-ARS-APTRU, Stoneville, MS
• Dr. S.J. Thomson - Research Agricultural Engineer, USDA-ARS-APTRU, Stoneville, MS

Presently, no viable method has been adopted by producers to monitor soil moisture or crop water status for scheduling irrigation of cotton in the Mississippi Delta. This is due in part to the difficulty in collection and interpretation of the results obtained from routine crop and soil moisture measurements, such as pressure bomb and tensiometers. Also, the need for extensive sampling required in a production setting limit utility of these direct physical measurements due to time and money constraints. A producer's field and crop experience, general rules of thumb and in-season rainfall are usually used to determine the need for irrigation. Given the increasingly tight economic constraints placed on producers in today's global market, higher-level management is required to realize a profit. Remote sensing may offer producers the potential for straight-forward determination of crop water status, with little effort and time on their part.

Remote imagery will be provided by NASA in collaboration with the Engineering Research Center at Mississippi State University. Multi-spectral images and thermal imagery will be analyzed during two drying cycles to determine utility of using imagery for crop water management. Examination of these images will be performed for cotton under different crop water conditions (irrigated or non-irrigated and/or subsoiled or non-subsoiled) and for cotton in a field with varying soil types. Plant water status, soil water potential, soil and canopy air temperature and plant growth factors will be monitored during the drying cycles along with gathered spectro-radiometer data to correlate with the remote-sensed data. Remote imagery from NASA will be supplemented with data from a video imaging system currently under development at USDA-ARS-APTRU. The aerial video system uses a digital video camera mounted under an Air Tractor AT-402 spray plane, and attached to a device that records GPS data to the audio track of the video tape.

This research program will endeavor to develop irrigation scheduling techniques from remote imagery for soils and tillage practices of the Mississippi Delta. Development of water stress signatures in remote imagery could define areas of low water availability and should indicate water stress. In the end, for remotely-sensed data to be practical for irrigation scheduling the method must be sensitive to crop water status, be frequent, reliable, timely, cost effective, and be easy to use and interpret.