Temperature and Moisture Regimes in Soils Mulched with Transparent Polyethylene

Abstract A numerical one‐dimensional model was developed in order to study the effect of soil mulching with transparent polyethylene film upon the soil moisture and temperature regimes. Environmental conditions, soil physical characteristics, and optical properties of the cover are considered. Calculated moisture and temperature profiles were compared with observed ones in experimental field plots. It was shown that soil moisture and temperature distributions are significantly influenced by the polyethylene mulch. The results indicate that the numerical model accurately predicts the soil moisture and temperature regimes in two tested soils. In both a Rehovot sand soil and a light clay soil, experimental and calculated results showed that the temperature maxima of the soil increase with increasing soil moisture content. In the light clay soil both the experimental and numerical results showed that the tarping of the soil with transparent polyethylene caused a significant increase in soil moisture in the upper soil layer. At close to air‐dry moisture content, the maximum temperature of the light clay soil indicated a much higher value than the wettest mulched plot of the same soil. Physically based explanations are given for the measured and computed results.