DEEP PLOUGHING BY DYNAMITE

Taranaki Daily News, Volume LIV, Issue 270, 11 May 1912, Page 1 (Supplement)

DEEP PLOUGHING BY DYNAMITE

TNTREASTXr: CROPS A\D PROTECTION ACATXST DROUGHT. Leading agricultural authorities everywhere are advocating deep tillage both as a means to increasing crops and as protection against such disastrous dry spells as characterised the summer of 1011 in Great Britain. There seems to be no difference of opinion as to the advantages of deep tillage, but there is in regard to the method of doing the work. AY hat might be called the natural method is the planting of crops such as lucerne, whose large and powerful tap roots will penetrate a rather compact subsoil to a depth of six feet or more, and in a few years render it more or less open and give it a suflieient content of humus to materially increase its fertility and water-holding capacity, A more rapid method of deep tillage is with the subsoil plough which breaks up the soil to a depth of fifteen to twenty -inches. This, however, is rather expensive, and very hard on men and horses. Within recent years a third method of subsoiling lias been the subject of extensive experiment, namely, with dynamite. The results of these experiments, when they were conducted under proper conditions, have been quite remarkable.. Cotton yields have been doubled, tripled and quadrupled by subsoiling with dyna-

t'.iill li.»» r.-i-pumK-it >piemlidly i«> this treatment. Cereals, liny, fruit trees, tomatoes, beans, watermelons ami various oilier crops have all shown substantially increased yields when the subsoiling iias been done in dry weather, preceding the rainy season. ASTON ISIII NO RES L" LTS. The publicity given to these iistonishins; results, which point to a revolution in farming methods, lias naturally created much enquiry in the minds of the farmers as to the cost of sub,soiling and length of time before subsoilcd land will have to be again subsoiled in order to keep it open. This question is obviously dillieult to answer, e, with the exception of a few pioneer users of dynamite, most of the remarkable results noted have occurred within the last year or two.

Fortunately, however, there were enough of the pioneer users to prove that the effect of subsoiling lasts for many years. The cost averages about £3 an ' aero, including dynamite, caps, fuse, and the labor of making the holes and doing the blasting. fn most cases the cost is recovered within a year, out of the increased yield, but in other cases, where the increased yield would not be worth more than ;C3 an acre, it is important to know how long this increased production is going to keep up so as to justify the expense. Let us first consider the matter from a theoretical point of view. The reason why deep tillage or subsoil ploughing is desirable is that all the soil below the bottom of the ordinary plough ant—in other words, everything below six to eight inches—is stiil in its primeval condition. It has never been disturbed. Chemical analyses of soils down to a depth of 20ft show that on the average acre there are tons of plant foods which become available only when roots can penetrate to them, or when ascending moisture brings theirt up to the roots that cannot get down. Lucerne and other deep-rooted plants are called "soil makers." because they penetrate this compact soil, introduce humus, and provide a passageway for the descent and ascent of water which carries with it the soluble, fertilising elements, but many subsoils are so hard that it is practically impossible for any one plant to pcnetrjti' them. Even when ibis is impossible there is no use in putting such a burden on the plant, because whatever vitality is expended in making its own home beneath the surface is substract.ed from the vitality of the plant above the surface. Til other words, the plant that has to fight for ittf life beneath the soil has little energy left for fruition. If we make root growth easy and quick by breaking up the subsoil, then we make the fertilising elements of the subsoil immediately available and save the energy of the plant for fruition. We also create in the subsoil a porous condition favorable to the storage of water to a depth that will not keep the soil cold, and yet near enough to the roots to feed them through capillary action.' Subsoiling also introduces air into the soil, and it is just as necessary for the; roots of a plant to have air as it is for ] a human being to have air. j