ARS | Publication request: Soil water balance calculation using a two source energy balance model and wireless sensor arrays aboard a center pivot

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: June 28, 2012
Publication Date: October 22, 2012
Citation: Colaizzi, P.D., Oshaughnessy, S.A., Evett, S.R., Gowda, P., Howell, T.A. 2012. Soil water balance calculation using a two source energy balance model and wireless sensor arrays aboard a center pivot [abstract]. ASA-CSSA-SSSA Annual Meeting Abstracts. 2012 CDROM. Paper No. 59-6.

Interpretive Summary: Irrigation of crops is important to maintain abundant food for a growing population. However, crop irrigation requires large amounts of water and energy. These are expensive and becoming less available. Therefore, it is important for farmers to conserve water and energy when irrigating crops. Conserving water and energy requires good irrigation management methods. One way to manage irrigation is by sensing crop temperature. The crop temperature is related to the rate of crop water use, which in turn is related to need for irrigation. A new method to sense crop temperature is by using wireless sensors on center pivots. Many crops are irrigated using center pivots, so this method promises to be very useful. We tested this method with a center pivot. The method can be useful for managing irrigation and conserving water and energy.

Technical Abstract: Recent developments in wireless sensor technology and remote sensing algorithms, coupled with increased use of center pivot irrigation systems, have removed several long-standing barriers to adoption of remote sensing for real-time irrigation management. One remote sensing-based algorithm is a two source energy balance (TSEB) model, which only requires a single view of directional brightness temperature, routinely available meteorological variables, and basic crop phenology. The TSEB calculates the energy budget of the soil and canopy separately, providing calculation of evaporation (E), transpiration (T), and evapotranspiration (ET). The TSEB was tested where directional brightness temperature was measured by wireless sensor arrays aboard a center pivot, and ET was calculated and applied to a soil water balance. The calculated soil water balance was compared to that derived from direct measurements of the soil water profile using field-calibrated neutron probes. This application of the TSEB combined with wireless sensors may provide an operational method to calculate the soil water balance of center pivots, which could greatly improve crop water productivity.