OCR Text |
Show -10- indicated on the soil and land classification maps developed for the valley. In the development and subjugation of the Colorado River alluvial lands, procedures should be followed to obtain a reasonable balance between the input waters and the output waters in maintaining a good agriculture for the valley. Irrigation requirements, according to the various soil textures and their hydraulic permeabilities including the infiltration and retention rates, crops adapted, and following the requirements set forth in the irrigation guide, are very necessary to carry on a permanent and good agriculture. These requirements include length and width of irrigation runs, grades, size of heads and irrigation frequencies, all based on soil data and varying soil characteristics found in the soil and land classification surveys of the valley. Fertilization The soils of the valley and the irrigation water contain all the plant food and mineral requirements of plants with the exception of nitrogen and phosphorus. Fertilization of agricultural crops with phosphate and nitrogen are necessary for high production. Phosphorous needs of leguminous crops are high, consequently high applications of the phosphate fertilizers are required for the production of alfalfa, clover, beans, vetch, etc. Nitrogen, an essential plant food in the growth of all plants, is in very short supply in the soils of the valley, with the exception of the leguminous crops, which produce nitrogen in symbiotic relationship with certain soil micro- |
Source |
Original book: [State of Arizona, complainant v. State of California, Palo Verde Irrigation District, Coachella Valley County Water District, Metropolitan Water District of Southern California, City of Los Angeles, California, City of San Diego, California, and County of San Diego, California, defendants, United States of America, State of Nevada, State of New Mexico, State of Utah, interveners] : |