Yield and chemical composition of corn and oats grown at different root temperatures in soil and nutrient solutions at different phosphorus levels

The growth of plants is greatly influenced by temperatures of the environments in which they exist and are dependent upon the temperatures both above and below the soil surface. It is possible for the air temperature to be favorable for plant growth and the root-zone temperature unfavorable. The temperature effect could manifest itself in the plant by increasing or decreasing the metabolic activity of both tops and roots. For example, there may be a decrease in water uptake by the plant or there may be an accumulation of ions of one or more species over others available in the growth medium. Numerous investigations have been concerned with the effects of temperature on plant growth. Most of these, however, have been concerned only with the overall air temperature in the fields and greenhouse with no consideration given to the effects of root temperatures. Others, working under greenhouse controlled environments have studied the temperature effects on plant growth as affected with similar temperatures of tops and roots. Relatively little work has been directed toward the specific effects of controlled root temperatures on mineral absorption. The purpose of this investigation was to determine some of the effects of different root temperatures on the up-take of nutrient elements from both soil and nutrient solution culture while maintaining a constant air temperature.