Location: Soil and Water Management ResearchTitle: ET from water balance considering dewfall and frost in a semi-arid continental climate
|Evett, Steven - Steve|
|Brauer, David - Dave|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/31/2023
Publication Date: N/A
Technical Abstract: Dewfall and frost accumulation are not considered in the energy and water balance simulations in most crop models. Dew and frost are often assumed to be negligible parts of the energy and water balances that can be safely ignored. This may be largely the case during the middle of the growing season when evapotranspiration (ET) rates are relatively large and plant and soil surfaces relatively warmer than during other seasons. Crop models are now, however, being used to model multi-year cropping cycles, including the water balance during the off season when precipitation capture and storage in the soil profile is affected by choice of tillage system, resulting residue cover or cover crop, and other factors that may result in different outcomes in terms of soil water storage at planting time. Detailed analysis of large, precision weighing lysimeter data from Bushland, Texas, has now involved algorithms, backed up by manual intervention, for detecting dew and frost accumulation on a five-minute basis for every day of the year for multiple crops (alfalfa, corn, cotton, sorghum, soybean, sunflower, winter wheat) spanning 30+ years. Dew and frost accumulation was found to account for up to 40% of daily water balance during the off season, providing motivation for the inclusion of more sophisticated and compete energy and water balance algorithms in crop models.