Submitted to: Scientific and Technical Review
Publication Type: Other
Publication Acceptance Date: 1/3/2014
Publication Date: 1/3/2014
Citation: Evett, S.R., Schwartz, R.C. 2014. Annual report to W-2188 multi-state research project "Characterizing Mass and Energy Transport at Different Vadose Zone Scales" Scientific and Technical Review.
Interpretive Summary: Soil water sensing systems and systems for directly measuring crop water use (evapotranspiration, ET) are important tools for improving irrigation scheduling and obtaining the maximum yield per unit of water applied (maximizing water use efficiency). In the increasingly water-short irrigated regions of the U.S., improving yield per unit of water use is imperative for making best use of scarce resources, reducing pumping costs and improving farm profitability, as well as sustaining rural economies. Scientists at the USDA-ARS Conservation and Production Research Laboratory, Bushland, Texas, studied several soil water sensing systems and compared them with soil water storage measured using precision weighing lysimeters to determine which system best estimated soil water content. They also improved weighing lysimeter designs and helped users in several states to improve their operations and studies of crop water use. The Bushland findings on effectiveness of soil water sensors as well as well as their limitations were communicated to sensor manufacturers to help make improvements to sensor designs. The important results of these studies were recognized both nationally and internationally, resulting in 21 invited presentations to workshops on crop water use and irrigation management to irrigation associations, and national and international organizations in 2013.
Technical Abstract: Results of our studies on soil water sensors were conveyed to manufacturers, including Acclima, Inc. and Decagon, Inc. Four invited presentations on soil water sensing for irrigation management were made to irrigation conferences in the Central and Southern High Plains (Nebraska and Texas). Eleven invited presentations were made to a four-day national water management workshop organized by Ondokus Mayis University in Turkey in July, and guidance was provided to three research groups interested in deploying weighing lysimeters for their research in Turkey. Two invited presentations on sensing of soil water content and bulk electrical conductivity were made in July to the First Research Coordination Meeting (RCM) of the Coordinated Research Project (CRP) on “Landscape Salinity and Water Management for Improving Agricultural Productivity”, International Atomic Energy Agency, Vienna, Austria, resulting in modified research approaches amongst the participants from Bangladesh, China, India, Pakistan, Uzbekistan and Vietnam. An invited presentation on multi-scale evapotranspiration and remote sensing studies was made to the Geological Society of America Annual Meeting at Denver in October. An invited presentation on soil water sensing was made in November to the University of Bonn, Center for Remote Sensing of Land Surfaces (ZEF) and Center for Development Research (ZFL) ZED/ZFL Colloquium, and discussions with graduate students influenced their research approaches. An invited keynote presentation on weighing lysimetry to study evapotranspiration was made in November to the Workshop on Investigating Hydrological Fluxes Using Long Term Lysimeter Data, Forschungszentrum Jülich, Jülich, Germany, and was part of the discussion formulating an international research approach. Ten presentations (three invited) related to soil water sensing and crop water use at multiple scales were made at the Annual International Meetings of ASA, CSSA, and SSSA in Tampa in November.