Practical Farm Drainage: A Manual for Farmer and StudentJ. Wiley & Sons, 1908 - 188 頁 |
其他版本 - 查看全部
常見字詞
acres alkali April constituted become bottom Box drain branch channel Chapter construction cost covered drain creek crops cultivation depth desired dike discharge distance drain tile drains laid earth eleva excavated excess of water farmer feet deep filled flow four feet grade elevation grade line grade peg grains gravity ground guide stake hillsides hundred feet inches increased injury intercepting irrigated irrigated land junction labor less level notes loam lower moisture natural drainage necessary open ditches outlet owner pass percolation pipe plant pond Portland cement practice preliminary level rainfall removal road rod reading roots salt marshes sand saturated seep side silt basins six inches sizes of tile slope soil structure soil water South Field spade spirit level stagnant water stratum submains subsoil sufficient surface inlets surface water surplus water system of drains tile drains tion trench underdrains vitrified water-table
熱門章節
第 80 頁 - An excavation was made in the field to the depth of six feet, and a stream of water was directed against the vertical wall of soil until it was washed away, so that the roots of the plants growing in it were laid bare. The roots thus exposed in a field of rye, in one of beans, and in a bed of garden peas, presented the appearance of a mat, or felt of white fibres, to a depth of about four feet from the surface of the ground.
第 81 頁 - Mass., and presented to the College museum by Mr. BH Averell. Prof. Stockbridge, last fall, washed out a root of common clover, one year old, growing in the alluvial soil near the Connecticut River, and found that it descended perpendicularly to the depth of eight feet. Mr. Mechi, of Tiptree Hall, England, tells us that the reason clover is usually so short-lived, is the fact that the lower roots are either unable to penetrate the subsoil or to find in it the requisite supplies of food. He also states...
第 97 頁 - T," in which the angle between the two is a right angle. In the former, the currents from the two pipes unite with the least possible resistance, so that the flow of neither is materially checked. It is frequently necessary to have the general direction of the laterals at right angles with the main, but the joinings can be made with Y junctions in the manner shown at b in Fig.
第 85 頁 - A\: 54Z) in which Q = Discharge in cubic feet per second. A = Area of tile in feet. D = Diameter of tile in feet. F = Total fall of drain in feet. L = Length of drain in feet. The number of acres drained is found by dividing the discharge by a constant representing the number of cubic feet per second necessary to relieve one acre of a given depth in 24 hours. The constants most...
第 151 頁 - ... the method of building roads. The question of foundation for roads over clayey and other non-porous soils is receiving the careful consideration of the commission. The telfording foundation and centre V-shaped drains are being closely watched with reference to their behavior when the frost is coming out of the ground in the spring.
第 90 頁 - ... ditcher, with his simple tools, will always be in demand, and the excellent manner in which he performs the work will never cease to be the criterion in the making of farm drains. The...
第 96 頁 - Junctions of branch or lateral drains with their main should be made by the use of junction tile, which should be put in place when the main is laid. Not all manufacturers make junction tile, or junctions, as they are called. Some only make a hole in the...
第 21 頁 - Fertilizing gases held in the air, or artificial fertilizers applied to the soil are carried by rains directly into the soil, instead of passing off over the surface. 4. Crops are better able to withstand drought. The greater depth of soil and the extended range of roots, together with the change in the texture of the soil, rendering it capable of retaining more moisture, are among the agents which assist a crop to pass through a period of drought safely.
第 92 頁 - Gage. obtaining the grade indicated by the survey. In some cases the line is set high above the center of the ditch; in others crossbars are set for testing the grade by line of sight; but in all methods the principle is the same. While all are correct, and have their advocates, it has been found that the line and gage method is well adapted to farm use, and can be employed by workmen who do not succeed in using some of the others. The workman now takes out the bottom draft, or "spading...
第 98 頁 - Blinding is fixing the tile in place by chipping moist earth from the side of the ditch so that it will distribute itself about the tile. This earth should be carefully but lightly tamped about the tile so as to hold them firmly in place, after which sufficient earth should be sliced off the side of the ditch to cover them six inches deep.