The effects of shallow saline groundwater on evaporation, soil moisture, and temperature distribution in the presence of straw mulch

Abstract

Mitigating evaporative water loss from terrestrial surfaces is of central importance to water resources management in arid and semi-arid regions. This study was intended to experimentally address the effect of straw mulch layer on soil evaporation and temperature distribution in the presence of shallow saline groundwater. A factorial-based experiment with a completely randomized design was carried out in mini-lysimeters (MLs) with different concentrations of saline groundwater and soil types, with and without straw mulch. The lysimeters were placed on the soil surface in the field. Water table in MLs was kept at the depth of 60 cm, and evaporation rate, soil moisture content, soil salinity, and temperature were continuously monitored. The analysis of variance (ANOVA) indicated significant differences in the soil evaporation rates due to the effects of soil types (i.e., loam and sand) and straw mulch (p < 0.01). The results showed that soil temperature fluctuations at the 5 cm depth in loamy soil with and without mulch were 11.5 and 17.5 °C, while in sandy soil the fluctuations rates were 15 and 18.5 °C, respectively. The application of a mulch layer was found to significantly reduce the evaporative loss by 27 and 8% in loamy and sandy soils, respectively.

Keywords

• bare soil
• evaporation
• soil temperature
• straw mulch
• water content