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<br /> <br />~ <br /><") <br /> <br />and lea,ve a fine earth mulch on top to cut down evaporation from the <br />moist .a1'th~ Evaporation is cut down as soon as the plants shade the <br />ground. It is evident from the above that to compare, as some do, <br />evaporatiQn and transpiration from cropped areas to evaporation from <br />water surfaces is entirely erroneous. <br /> <br />~ <br />"'"'. <br />Q <br /> <br />5. Tbe good farmer can tell by the appearance of a crop when it. needs <br />water and the application of water at any other time is detrimental to <br />the crop. RoweveJ:, a water supply is not always avaUable at the time <br />the failmer knows hi. crop needs it, so he is helpless and often suf1ers <br />II. diminution of his crop. <br /> <br />6. To assume that nature transpires water from growing vegetation <br />continuoue1y if moisture is avaUable is also erroneou., as is eviden- <br />ced by crop. grown in .ome localities in the Near Ea.t without any <br />vi.able moisture. <br /> <br />There "'1'11 thoUllands of acre. of broad leaf crop. grown in areas in <br />Syria and Jordan that the only moisture available is from dew. These <br />crops consist of cotton, tobacco, melons, corn, the maizes, egg plant, <br />temateCls, grapes, etc. This area has a rainy seaSOn ln the winter and is.". <br />comp1e~.ly devoid of rain in the summer or dry season. These C:1'OpS all <br />f1ouris~ although the ground und81' the plants is absolutely cI1'y and in <br />some b).tanees has cracks over two feet in depth. An enterprising Arab <br />fixed up a dew gage and measured it at about 2 inches per month. . Accord- <br />ing to the formulae used to determine consuntptive use in the ColoJl'ado <br />Elasm, these plants would never staJl't, let alone mature a crop. <br /> <br />The summer temperatures, wind movement, evaporation rate, etc. in <br />thie are_ .re almost identical with the Denver area--ma'Cimum 950 F. <br />eome days in .ummer with night temperatures around 600 F.;, average <br />humiditY l.u than Denver, as it never rains during the summer, evapo- <br />ration about 35 inches. <br /> <br />The growing of these crops demonstrates how little moisture nature re- <br />quires to produce crops and also demonstrates that nature can stop trans- <br />piration from vegetal surfaces, a factoJl' that the formula used to det.,r- <br />mine cotl,llumptive uses in the Colorado Basin did not consider. This <br />ability of: nature to stop transpiJl'ation is demonstrated by an attempt to <br />develop a water supply by removal of Salt Cedar in the GUll. valley. <br />According to the formulae, Salt Cedars consume some 4 feet of water <br />per year~ In the lat. nineteen fortys, a company was organized in <br />Arbona to develop 40, 000 acre feet of irrigation water by clearing <br />10,000 acres of Salt Cedar. On inquiry last year, they developed nothing. <br /> <br />7. 11 Salt Cedar transpired four acre feet of water per year, there wowd <br />be deposited O. ?lb. of salt for each s<1uare foot of Salt Cedar area each <br /> <br />-z.. <br />