Minimizing Temperature Fluctuations of Sandy Soil Under Different Climatic Conditions

SANDY soils, in the arid regions, usually suffer from extreme temperatures. Such high temperature fluctuations can be harmful for plant growth. This investigation aimed to: 1) detect soil thermal regime of Ismailia coarse texture soils; 2) study soil temperature fluctuations under different climatic conditions; 3) determine evaporation rate of soil water; 4) study the effect of some soil surface treatments on the 2^nd and 3^rd points. All the four aims were studied under both summer and winter conditions. The investigated soil surface treatments included transparent plastic mulch, rice straw mulch, application of bentonite, and the control. Obtained results revealed that, the thermal regime of Ismailia sandy soil was Hyperthermic. The response of soil temperature to air temperature fluctuation was more pronounced during winter compared to summer conditions. The highest soil temperature fluctuation was obtained under transparent plastic mulch and the lowest was obtained under rice straw mulch, during both summer and winter seasons. The highest soil temperature values recorded under plastic mulch can be harmful for plants during the summer, but may enhance plant growth during the winter. Both rice straw and plastic mulch reduce the water loss by evaporation from soil surface, as indicated from the evaporation rate. Bentonite incorporation with the soil surface layers had small effects on both soil temperature fluctuation and water evaporation rate. It is recommended to use straw mulch for moderating soil temperature fluctuations and reducing water loss by evaporation during summer and winter seasons.