A simple process-based model for estimating windbreak effects on soil temperature during early crop growth stage

Abstract

A model was developed to estimate the windbreak effects on soil temperature during the early crop growth stage using the windbreak structure and readily available meteorological data at a reference position. In this model, the windbreak effect on wind speed was estimated from the width and total area density of the windbreaks using an equation parameterized by the data at 13 windbreaks. Windbreak effects on solar radiation were estimated on the basis of the Beer–Lambert law, and the effects on soil temperature were estimated on the basis of the heat conduction equation and the extended force-restore model with the boundary condition of heat balance on the ground surface. The model was validated with 3 years of observations in maize fields with windbreaks in Hokkaido, northern Japan. Our model could reproduce the observed spatial distribution of mean soil temperature during the early growth stage of maize with an increase of 0.4–0.8 °C by wind speed reduction at 3–4 H (H = windbreak height) and a decrease of 0.9–1.0 °C by shade from windbreaks at 0.5 H. This simple process-based model provides a framework for the quantification of windbreak effects on soil temperature at fields with various windbreak structure and meteorological conditions.