ON DRAINAGE.

Dominion, Volume 5, Issue 1331, 8 January 1912, Page 8

ON DRAINAGE.

CHEAP A.\D EFFECTIVE METHOD. Most farmers have, at some time or other, had practical experience of the well-known fact that badly-drained soils grow but indifferent crops. They are, as a matter of fact, ' not worth cultivating. The resulting crop is usually such, a poor one .that it dors not pay to plough, cultivate, and sow this class of land. Notwithstanding that, these nudraiiied soils contain an abundance of moisture, and n .sufficiency of plant food. I hough mostly in an unavailable form, Referring to the advantages of draining, Mr. 11. lioss, Inspector of Agriculture, writing in the "Agricultural Gazette" of New South Wales, says :— On Drainage Generally. Drainage has an intimate relation to soil moisture. It is quito a false idea to hold that drainage dries,a \soiL out; its effect is quito the contrary. It is oiily the superfluous moisture, which would otherwise remain stagnant in the soil, and prevent the free circulation of air, that is removed by drainage. A well-drained soil, whether so artificially or naturally, acts as a reservoir for the storage of moisture. Such soils are porous and well aerated, and they are capable of holding more water in a capillary form than undvained soils. Another advantage lrhich drained soils possess over undrained soils is, that plants grown on drained laud are encouraged to root deeply, and are, consequently, betterable to withstand adverse conditions. In undrained soils, the root system is shallow, thus limiting the feeding area of the plant, furthermore, such soils are cold in the spring and the growth backward. But, perhaps, the most important aspect of the drainage question is that relating to soil fertility. The soil contains millions of tiny forms of bacterial life, necessary to make certain essential 'plantfoods available. This bacterial life cannot exist and pcrfyrin its functions except under certain conditions of warmth and aiv. In an undrained soil these' conditions are not present, consequently bad-ly-drained soils may be said to be "dead," whereas a sweet and more porous soil is teeming with these minute micro-organ-isms, which play such an important part in the production of growth. Surface drainage does not, as a rule, act as effectively as under-drainage. By cinployiug under-drainage, the water, sinking through the soil by gravitation, carries with it a large mass of useful materials in the shape of plant-food, which, for the most part, remains when the surplus water is removed by drainage, to beaftcrwards mado use of by (he plants. Such, however, is not the case with surface drainage, where the surplus water, (lowing near the surface, carries away with it particles of materials which might become plant-food, but are thus lost. A Cheap Drsin. On many farms one finds patches of from 5 to 20 or more acres of undrained and sour land, which the farmer does, not think worth cultivating, and which, in fact, if cultivated, would hardly give any return. Still these patches can easily be reclaimed, sweetened, and, by an inexpensive system of drainage, be made a source of profit and an asset to the farm. Often farmers cannot afford a system of drainage tvit-LJ pipes or tiles, audi frequently the value of the land docs not warrant such an expenditure; but cheap and thoroughly effective drains maybe constructed in the following manner:— After the natural fall of the land to be drained has been ascertained, a trench Ift. wide and 2ft. Gin. deep is dug. Into this, trench, to a depth of from 0 to 12 inches, saplings of any length, from I to (i inches in diameter, are thrown. On top of this is placed brushwood to n depth of about 5 inches, and then the excavated earth is scooped back level with the .'..urface of the laud. The water to lie drained off will lie touiul to percolate freely through the f.paeos between the saplings. The brushwood (bracken fern or similar undergrowth) prevents the earth from falling into the space filled with timber. As ihe earth is scooped back In a depth of 12in., the drains do not interfere with Ihe ploughing, etc., whereas if the drains had been left open, they would hamper the working of the laud. Be.-fdes (hi-, Ihe sides of open drain- are constantly breaking loose, thiir interfering with and blocking Ihe wnlercoui-.-e.

The writer says he has a t various limes constructed drains of (his description, which have invariably proved effective and durable, at a minimum expenditure.