Factors Affecting The Soil Temperature And Its Control
1. Solar radiation:
The amount of heat from the Sun that reaches the earth is 2.0 cal/cm2 min -1 the amount of radiation received by the soil depends on angles with which the soil faces the Sun.
Whenever water vapour from soil depths or atmosphere condenses in the soil, its heat increases noticeably.
The greater the rate of evaporation, the more the soil is cooled.
Rainfall cools down the soil.
A bare soil quickly absorbs heat and becomes very hot during the summer and become very cold during the winter. Vegetation acts as a insulating agent. It does not allow the soil to become either too hot during the summer and two cold during the winter.
6. Colour of the soil:
Black colored soils absorbs more heat than light closured soils Hence black color soils are warmer than light colored soils.
7. Moisture content:
A soil with higher moisture content is cooler than dry soil.
The cultivated soil has greater temperature amplitude as compared to the uncultivated soil.
9. Soil texture:
Soil textures affect the thermal conductivity of soil. Thermal conductivity decreases with reduction in particle size.
10. Organic matter content:
Organic matter reduces the heat capacity and thermal conductivity of soil, increases its water holding capacity and has a dark color, which increases its heat absorbability.
11. Slope of land:
Solar radiation that reaches the land surface at an angle is scattered over a wider area than the same amount of solar radiation reaching the surface of the land at right angles. Therefore, the amount of solar radiation reaching per unit area of the land surface decreases as the slope of the land is increases.
Soil temperature can be controlled by:
1. Regulating soil moisture.
2. Proper soil management practices so a to have good drainage.
3. Application /use of mulching.
4. Sufficient addition of organic matter.