Soil temperature and plant growth
Soil micro-organisms show maximum growth and activity at optimum soil temperature range. All crops practically slow down their growth below the temperature of about 9⁰C and above the temperature of about 50⁰ C. The biological processes for nutrient transformation and nutrient availability are controlled by soil temperature and soil moisture. Soil temperature has a profound influence on seed germination, root and shoot growth, and nutrient uptake and crop growth. Seeds do not germinate below or above a certain range of temperature but Micro-organisms functioning in the soil are very active while a certain range of temperature, which is about 27⁰ to 32⁰C. It is necessary to know whether the soil temperature is helpful to the activities of plants and micro-organisms and the temperature could be suitably controlled and modified. The various factors that control the soil temperature are soil moisture, soil colour, slope of the land, vegetative cover and general soil tilth. Aeration can be used to control soil temperature, regulate soil moisture, improve drainage, stimulate microbial activity and improve overall soil tilth.