Requirement and Availability of Soil Water

Effect of Drought Conditions at Boiling Stage on Some Chemical Constituents of Cotton Plant

“…The increase in sugar content in roots of wilted plants were 77, 14 and 12 % for reducing, non-reducing and total soluble sugar in 1987 season respectively, while these values were 43, 14 and 11 % for the same respective components in 1988 season. The increase in sugar contents observed in roots may be due to the tendency of polysaccharides to break down to soluble carbohydrate as a result of increasing hydrolytic enzymes under drought conditions (TAKAOKI 1960) and this may be accompanied by its deposition into roots (KELLEY 1952). Similar results were obtained by AHMED (1984), who concluded that drought conditions increased soluble sugars in roots in cotton plants.…”

Effect of various soil, climatic and management factors on the response of corn to applied fertilizer

“…The validity of this observation is substantiated by the voluminous literature re lating crop yields to climatic conditions. Some of the climatic factors most often studied are rainfall, temperature and relative humidity (Kelley, 1954). Davis and Pallesen (1940) used orthogonal polynomials to study the effect of rainfall on corn yields at Wooster, Ohio, from data collected over a 32 year period .…”

The availability of soil moisture to plants

“…From tension and con ductivity considerations already discussed and from the volume of accumu lated evidence (see Jamison, 1956;Kelley, 1954) it is clear that moisture availability and plant growth decrease progressively as the wilting range is approached. In view of the energy relations such a decreasing availability is to be expected.…”

“…In view of the energy relations such a decreasing availability is to be expected. Jamison (1956) and Kelley (1954), in-their Concerning the movement of moisture through the soil and into the plant, Ehlig (1962a, 1962b) compared the total impedance to water movement from soil into plant with the impedance predicted for soil alone. They developed the following equation for the uptake of water by 23 plants:…”