High-resolution Tracking of Root-zone Soil Moisture Availability for High-value Irrigated Crops
Abstract
Irrigation plays a large and growing role in global agricultural production. However, the expanding water-use footprint for irrigation agriculture is increasingly coming into conflict with competing users. Studies have demonstrated that opportunities exist for a reduction in irrigation applied to Californian grape and almond crops without negative impacts on either harvest quality or yield. However, excessive water stress can damage the carrying capacity of almond trees and grape vines over multiple seasons and, therefore, represents a serious risk for producers. Improvements in our ability to accurately map soil water availability (i.e., root-zone soil moisture, RZSM) are needed to give producers the necessary confidence to optimize irrigation water-use strategies in the face of this risk. Unfortunately, RZSM levels are notoriously difficult to track in a high-resolution/spatially continuous manner since, when applied individually, existing RZSM estimation approaches (e.g., in situ observations, soil water balance modeling, microwave remote sensing and thermal-infrared remote sensing) are all subject to well-known limitations. This implies that integrative and/or data assimilation approaches, that integrate across multiple methods, should be targeted. Here, we will describe the development and operational application of the Vineyard Data Assimilation (VIDA) system to track high-resolution (30-m) daily RZSM variations within vineyards and orchards in the California Central Valley. VIDA is based on the simultaneous assimilation of microwave-based surface soil moisture retrievals and thermal-infrared-based evapotranspiration estimates into a soil water balance model using an Ensemble Kalman filter. Using operational VIDA products generated for the 2020 and 2021 growing seasons along with soil moisture profile observations, we will discuss prospects for meeting RZSM product requirements for irrigation managers in the grape- and almond-growing communities using current and planned satellite remote sensing sources. We will also highlight remaining data assimilation challenges affecting the VIDA RZSM analysis.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFM.H31F..01C