Irrigating Crops With Seawater :: Freshwater Essays

Brown J. Jed, Glenn Edward P., and O’Leary James W. 1998. Irrigating Crops with Seawater. Scientific American. Irrigating Crops with Seawater'; talks about the global problem of finding enough water and land for the world’s population to survive. An estimated 494.2 million acres of cropland is needed just to feed the tropics and subtropics for the next 30 years. However, only close to 200 million acres are available. Therefore, new sources of water and land are needed to grow crops. The writers of this article have been testing the prospect of using seawater in agriculture. This seawater agriculture is when salt-tolerant crops are grown using ocean water for irrigation. Desert areas take up 43% of the surface of the earth and this new agriculture technique can be done in deserts. Hugo Boyko and Elisabeth Boyko first used seawater agriculture after World War II. Many different crops have been tested such as barley and the date palm. The writers of this article however have been testing halophytes, which, is a salt-tolerant plant that can be used for food, forage and oilseed crops. They f irst gathered several hundred halophytes and began testing these plants in the desert of Puerto Peà ±asco. They irrigated the plants daily by flooding the fields with seawater from the Gulf of California. The best halophytes produced roughly the yield of alfalfa using freshwater irrigation. In order to show that these halophytes could replace other crops for use they tested to see if the crops could feed livestock. The halophytes have protein and carbohydrates but they contain too much salt. This limits the amount an animal can eat and dilutes the nutritional value. Therefore, the authors decided to use the halophytes as part of a mixed diet for the livestock. The animals’ meat taste was not affected, but the animals eating the halophyte-mixed diet drank more water and produced 10 percent less meat.   Ã‚  Ã‚  Ã‚  Ã‚  This new agriculture method has many advantages too. First, it is cheaper to pump the seawater than to pump freshwater. In addition, seawater irrigation does not require any special equipment. The same fields have been irrigated for 10 years with no water buildup or salts in the root zone. Finally, installing the seawater irrigation will not disrupt the ecosystems as much because they are installed on barren or almost barren areas. There are also some disadvantages to irrigating crops with seawater. First, a large quantity of high-salt drainage water that will contain unused fertilizer will be discharged back into the sea.