In certain irrigated districts the alkali problem is a menace. Any controllable factor which tends to increase the alkali content of the soil should be carefully considered in a successful system of soil management. In this connection the quality of the irrigation water is of great importance; the saline content of water has a marked influence upon the method and quantity to be used for irrigation. The factors which will contribute to an increase or decrease of the alkali content of the water must be clearly understood. The amount of the several kinds of alkali salts added to the soil by large or small applications of water must be clearly understood in order that the farmer may utilize the water supply to the best advantage. A knowledge of the quantity and nature of the alkali salts added to the soil will enable him to more systematically plan his crop rotation since crops vary in their power to resist the action of the several kinds of alkali
