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Show PART II PRESENT STATUS OF IRRIGATION acres formerly irrigated by conventional methods, however, have "been con- verted to sprinkler irrigation in recent years. Regulatory reservoirs are used to provide water for numerous small irrigated tracts and miscellane- ous irrigation projects while direct diversion structures are provided on perennial streams for two major Indian irrigation projects located on the Navajo Indian Reservation near Shiprock, N. Mex., and on the Uintah and Ouray Indian Reservation in the Uinta Basin of Utah. View of sprinkler on close plantings of corn in the Upper Main Stem Subregion of Colorado. Throughout the Upper Colorado Region crop diversification is most successful in areas served by irrigation projects on the main stream or with storage facilities to supply late-season water. Stable water sup- plies encourage practices such as land leveling, improved methods of ir- rigation, drainage, proper crop rotation, improved plant species, and use of commercial fertilizers. These result in improved yields. Improvements on irrigated lands including assistance in applying on- farm water management and conservation practices has been given impetus by soil conservation districts organized in the 1930's. On-farm water management is essential in preventing excessive waste water runoff, deep percolation, water logging, soil erosion, and loss of plant nutrients. It also has a direct effect on the water quality in the irrigation return flows. Conservation practices are a prerequisite to water management in 20 |
