Temperature is a basic measurement of the energy status of the environment and is largely influenced by the sun’s radiation. Temperature is simple to measure and is used, together with rainfall of an area, to determine which crops would grow best in that specific area.
However, temperature parameters such as average daily and seasonal temperatures, minimum and maximum temperatures, optimal and diurnal (day and night) ranges should be taken into account of how well a crop would grow in that area.
Temperature has a direct effect on all forms of life on earth. It creates human comfort or discomfort (and a need for heating or cooling), determines crop and animal responses, the occurrence of pests and diseases as well as rates of evaporation and transpiration (moisture loss by leaves).
How is Temperature Measured
The temperature used for the growing of crops and in farming is measured as the air temperature. This is measured inside shelters called Stevenson screens or ventilated radiation shields. These shelters are placed 2 m above the ground, near the level of the crop’s leaves. Air temperature may be different from ground temperature.
At night during winter, ground temperatures are much lower than the screen’s temperature. This can result in frost even though temperature forecasts did not predict freezing air temperatures. However, ground temperatures could also be warmer than air temperature during the day depending on the type of surface.
Open air temperature may also be warmer than the screen temperature, especially during summer. The temperature of leaves exposed to the sun is usually 3 - 4ºC higher than the measured (screen) temperature. The difference reduces to about 1ºC under shaded conditions and when temperatures exceed 33ºC. Thick non-transpiring leaves can be 10 - 15ºC warmer than the measured air temperature.
How to Convert Celsius to Fahrenheit
