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Show COVER CROPS BENEFIT Where Irrigation Water Is Abundant Alfalfa Is Grown. Being Deep Rooting Legume, It May Be of Advantage to Orchards Where Moisture la Plentiful Some Objections. Rucxetisful Irrigation Is not conditioned condi-tioned upon clean cultivation; In fact, it may lie quite otherwise Cover crops are sometimes of and vantage. Recent practice In some parts where Irrigation water Is abundant beyond the requirements of the tree, Is to grow alfalfa in the orchard. Hclng a deep rooting legume, It may be of advantage ad-vantage to the trees In the presence of ample moisture, while with scant moisture it would rob the trees and practically ruin them. In the hot Irrigated Ir-rigated valleys of Arizona a cover crop of alfalfa reduces the soil temperature, tem-perature, prevents the reflection of heat which occurs from a light-colored soil surface, and Is said to Insure thrifty young trees where clean culture cul-ture destroys them. In cooler parts of the arid region, as In the mountain valleys of northeastern California and In Idaho, alfalfa is bIho grown In Irrigated orchards. These facts are of wide significance as showing that Irrigation Irri-gation may be found of iM-neflt even where clean culture may not be thought desirable. It is certainly rea sonalilo that if a cover crop is grown at all It should be attended by the surety that the trees shall cot suffer for moisture, and they unquestionably do sometimes suffer serkmsly under old turf, even in landj of summer rains. This view Is wholly apart from the subject of exhaustion of soil fertility by Intercropping. Of course, compensation compen-sation for the depletion must be made by Use of fertilizers, and whether the Intercrop secured yields a profit upon such Investment Is a calculation foreign for-eign to this discussion. The purpose simply Is to emphasize the fact that on rich soil ample Irrigation can produce pro-duce good fruit on an Intercropped orchard, and It can do the same on a pnstured orchard, but the height and form of a cow-pruned fruit tree Is totally abhorrent to present Ideals. A cover crop and Intercrop are, however, somewhat different things. The growth of a cultivated crop between be-tween the rows of fruit trees Is permissible per-missible If the land is rich, and moisture, mois-ture, either by rainfall or by Irrigation, Irriga-tion, Is ample; but experience baa shown that sia-h a crop Is only protlt-able protlt-able while the, trees are very young. A the trees expand they repress the growth of the Intercrop below the profit mark, and give no further Inducement In-ducement to the grower to longer endanger en-danger the future of his trees by dividing di-viding their sustenance with the Intercrop. Inter-crop. On the other hand, a cover crop, If It be a legume, may re-enforce the humus in the soil. One of the objections to continuous clean culture In the arid region Is the tendency of the soil to lose humus and to bctome lifeless and refractory. The growth of clovers, peas, and other hardy legumes during the winter season, when the moisture Is usually abundant, Is being widely resorted to for the purpose of restoring humus. The summer grow th of tender legumes with ample Irrigation Irriga-tion Is therefore, for this reason, as well as for lowering the soli temperature tempera-ture and escaping other effects of excessive ex-cessive temperature, worthy of consideration con-sideration If water Is ample enough to support the cover crop and the trees. Clearly where such practice Is advisable ad-visable the irrigation method must be suitable If the land Is nearly level, low check levees on contour lines will restrain sufficient water and not Interfere In-terfere with the use of the mower. Such contour checks may inclose a considerable number of trees. With greater slope the square check system sys-tem Inclosing a single tree may be necessary, or flooding down the spaces between the trees, with a low levee along each row, may be the most available systen. except In small orchards, where pipe lines, hydrants, and sprinkling may be ued. Farmers Hulletln No. 116. |