Some Factors which Influence the Water Requirements of Plants

Abstract

The problem of the water requirements of crops is very important. The factors which are commonly considered to influence water requirements of crops are many, but the most of them are speculative and but few empirical. The interest in this subject is new and consequently not much investigation has been made. The above-described experiments were carried on with the view of ascertaining more in detail some of the factors which influene water requiremtnes of wheat. Every possible precaution was taken to avoid experimental errors. Standard and efficient methods were used in the investigations. Experiments were carried on in pure quartz sand, in sealed jars, and plants were watered with definite strengths of nutrient solutions. In order to ascertain the factors influencing water requirements under natural conditions, some experiments were carried on in the Palouse soil. The experiments show the following factors to influence the water requirements, namely, (1) kind of crop, (2) strength of soil solution, (3) age of plants, (4) amount of moisture in the soil. 1. Kind of crop--different kinds of crops take different amounts of water to produce a unit of dry matter. 2. Strength of soil solution--the strength of soil solution has influence on water requirements of plants. The amount of water to produce a unit of dry matter is decreased when the strength of solution in increased. Popularly speaking, a fertile soil will produce a greater yield with a less amount of water than will infertile soils, under similar conditions. 3. Age of plants--younger plants take more water than the older plants. The experiments show that the plants in the first period of their growth take more water than in the second period; and in the second period they take more than in the third. 4. Amount of moisture in soil--the plants grown in the soil having more saturation take more water to produce a unit of dry matter than the plants grown in the soil of less saturation.