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Show WHAT CAUSES SEEPED LAND Soma Watt of Water Will Occur Under Un-der Beat of Management, Making Drainage Eaaentlal. I By r. O KU.tfTT. Chief of tralna, I'nlted fltat Hurenu of Aarlculture ) The cauae of aeeped or overaaturat-ed overaaturat-ed land I the waste from Irrigation and U-akage from canala and laterala. The aklllful Irrigator may Inalat that If no more water la applied than la needed for growing and maturing tha eropa. and that If the canala are o conatructed that no aubatantlal amount of water escapee Into tha earth, no land will become too wet for farming purposes. It Is true that In many Instances Irrigators have been unduly prodigal In the use of water, particularly when the land la first subdued and watered. The art of economical Irrigation le usually learned learn-ed only when scarcity of water compels com-pels Its leas lavish use. In any event, under methods that we may expect will prevail, some waste of water will o cur nnder the best of management, making draining In many places essential essen-tial to profitable farming For these reasons an account of drainage con-dltlona con-dltlona In different localities and the methods of treating them, together with the results which have followed arlous drainage operations, will be of Interest to the holders of Irrigated farm lands. It should he observed as a general truth that water which produces permanent per-manent saturation rises from the bottom bot-tom of the saturated portion toward th surface. Waste from Irrigation first passes downward until a hard stratum of earth Is reached. This may b only a few feet. In which case the additions which accrue from the Irrigation of a few years will bring the ernianent ground water level to within two or three feet of the surface, sur-face, at which time Injury to farm crops will ensue. The distance to horizon of hard material may be much greater and the Intervening ground may permit free percolation. In which case a much longer tlme will he re-quired re-quired to fill the soil, because of the larger reservoir capacity and the relief re-lief afforded by underdralnape. It Is not the downward movement of water alone which occasions boggy or wet areas, but the lateral movement of ground wnter down a slope until a flat tract or surface depression checks the flow and causes an accumulation of water, which Is made known by Ita appearance, not, however, until the lower part of the soil hnve been filled. Such dcpreMslons or level areas receive re-ceive the accumulated waste watei proceeding from adjoining lands, which occupy a higher level. It will he wen that the saturated condition of the land which shows Injury Is not due to the water which Is applied directly di-rectly to Irrigate It, but to the surplus which percolates frem the higher lands, sometimes through eonsldernble distances, until It reaches the lower flat or depression. Drainage has been carried on In the weft to such an extent that certain methods are now practiced with reasonable rea-sonable assurance of success. Reference Refer-ence to some of these will Indicate th variety of procedure which la now followed, as well as the constructive difficulties which attend this class of Improvements. The development along this line which has taken place during the last five years Is most encouraging to holders of seeped land. Value of Irrigation. Irrigation will bring maximum crops while the land U new and full of plant food: but where the crops are sold year by year Irrigation will not of Itself assure good results. |
