| OCR Text |
Show GOOD FACTS OF IRRIGATION Knowledge and Experience Required to Determln Just When Crops Need Water and How Much. In order to determine Just when crops need water and when to apply it so that they will not 6uffer from drought nor be injured by too frequent fre-quent or too generous applications, requires a knowledge and experience that can be gained only by practice and a close observation of various crops under Irrigation. It Is the experience ex-perience of many practical Irrigator that if an unlimited supply of water Is available crops more frequently suffer from overlrrlgatlon than from, drought. It Is difficult to determine when the development of the crop la first arrested on account of a lack of moisture in the soil. Some experimenters experi-menters maintain that this point can be more definitely decided by an examination ex-amination of the soil than by the appearance ap-pearance of the plant, as the latter shows evidence of the check in Its growth some days after it has occurred. oc-curred. Usually it Is then too late to prevent serious loss, as the crop rarely rare-ly recovers from such treatment, and seldom reaches the development It would have attained if it had been irrigated ir-rigated at the proper time. Plants will usually Indicate by a change in color or by their general appearance whether they need water or when they have been overirrigated. Most field crops turn to a darker green when in need of water, and the leaves and stems show a tendency to droop or curl. The lower leaves assume as-sume a pale yellow. A crisp or dead appearance in the lower leaves is one of the best Indications that a plant needs water. Grain which has suffered from drought may mature, but the straw will be small and short and the kernels will be shrunken and Inferior in quality. Alfalfa and similar crops have the appearance of cured hay. Where field crops are overirrigated the color of the foliage becomes a yellowish green and the plants have a sickly appearance. These indications indica-tions vary with the quality of the soil, so that It is impossible to lay down fixed rules to govern the number or frequency of Irrigations. Only close observation for a number of years on the same farm will enable a person to tell by the appearance of the plants whether they need water or not. The amount of moisture in 'the soil may be determined with sufficient accuracy ac-curacy for the needs of the plant by examing a sample taken a few inches from the surface of the ground. If it clings together when molded into a ball and shows the print of the fingers, there is moisture enough present. If the earth falls apart when the land is opened, irrigation irri-gation is needed. |
