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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Water Management Research » Research » Publications at this Location » Publication #359715
Research Project: Develop Water Management Strategies to Sustain Water Productivity and Protect Water Quality in Irrigated Agriculture

Location: Water Management Research

Title: Model based study of crop evapotranspiration under canopy shading

Author
item YU, QIANG - Chinese Academy Of Agricultural Sciences
item SHAH, KRISHNA - University Of California
item Wang, Dong
item MA, YANBAO - University Of California
item WANG, ZHIFEND - Chinese Academy Of Agricultural Sciences

Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/19/2019
Publication Date: 6/22/2019
Citation: Yu, Q., Shah, K., Wang, D., Ma, Y., Wang, Z. 2019. Model based study of crop evapotranspiration under canopy shading. Agronomy. 9(6):334. https://doi.org/10.3390/agronomy9060334.
DOI: https://doi.org/10.3390/agronomy9060334

Interpretive Summary: Theoretical modeling and an experimental dataset are used to study water saving strategies by canopy shading. The pathway for crop water loss is through evapotranspiration (ET), and the primary driving force for ET is solar radiation. A potential management approach to reduce ET is to reduce solar radiation. This approach was evaluated by comparing different scenarios of canopy shading including covering the crop canopy over different durations of the daylight hours or using canopy of partial light permeability. The study indicates that crop ET can be reduced by 30-70% depending on the type of shading used, which can lead to significant water savings.

Technical Abstract: California has some of the key agricultural regions in the United States. However, in one of these key regions, the Central Valley, severe droughts are frequent leading to shortage of irrigation water. This has significant impact on crop yield and the agricultural-based economy of the region. It is imperative to develop new strategies to reduce overall water consumption in agriculture without affecting crop yield. A large fraction of irrigation water is lost due to the evapotranspiration process in the crops and the soil. The classical Penman-Monteith model has been used in the present work to analyze effect of different environmental variables on evapotranspiration. Some of the scenarios considered suggest that significant water savings can be achieved without much reduction in the amount of sunlight available to facilitate crop growth. The key strategy considered in this study is use of canopy to cover the crop field resulting in reduction in evapotranspiration. Among the strategies considered, the most promising strategy is to partially cover the crop field for a certain time window during the day. With this method, total evapotranspiration can be reduced by 37% from June to August. Since the canopy covers the field only partially during a certain time window, plenty of sunlight is still available to the crops.