THE FARM.

Pukekohe & Waiuku Times, Volume 4, Issue 97, 18 October 1915, Page 4

THE FARM.

Soils. Composition and Character. Recently Mr W. J. Spafford, the well known Australian Agricultural authority, delivered an instructive lec'.ure on "Soils." After having defined "soil" as "that portion of the loose earthy material covering the bulk of the exposed surface of the earth that comes within the reach of o;dinary tillage operations," and "subsoil" as "the loose earthy material immediately below the soil." Mr Spafford dealt with the origin of sou*, the work done by various soil constituents, the texture of different soils, the availability of mineral plant foods, and various other essential features of the important subject. He classified eoils as light or sandy heavy or clayey, loams, calcareous, organic, or pept. SANDY SOILS.

Sandy soilß, he said, must, as a rule, be considered rather poor tor sgrizultural purposes, btcause they were formed by the mechanical action of running water, and because of their natural open porous nature which admitted of both the soluble materials and the finer particles bting washed into the subßcil. Of the tbree main plant fv-ods they contained little phosphoric acid, and the nitrogen and potash were very quickly washed out of them These soil 3 were what wbs known as "warm" and "early" soils, lo other worde, plants came to matuiitv in them sooner than in the heavier sails, due to the fict that ihsy did lot bold much moisture, a large bulk of which when once cold took a long time to get warm. Sar.dy soils did not need much water to make them Eufficier.tly moi t, for seeds t'» geiminate in ihem, and for plants to grow well Ihe amounts oi moiiture in soils when plants b.gan to wilt were:—Coarse sind, 1.5 per cent; saidy loam, 7.8 per cent; p;at, 49.7 per cent. These figures indicated why ia years of raintall sandy soils often produce quite fair crup l , while the heavier soils were a complete failure. In handling sandy soils for cereal growing the pciits always to be borne in mind were that they were nototiouly dry (and as such liable to drafting), ard as a rule deficient in plant food, lime and organic matter. They should always, if pos.ible, be cultivated and then left with a slight crust on the surface. This would reduce the chance of much of the surface bhwing away. They should be cropped as little as possible, and stccked as much as possible. In this connection he suggested a five yeats' rotation of bare fallow, wheat with lucerne, lucerne, lucerne, lucerne, and four years'f rotation of bare fallow, wfceat with ryegrass, ryegras?, ryegrass. HEAVY OB CLAYEY SOILS. These soils generally were heavy to worir, clogged op all parts of impleimnt* ran together after most rains, and were "cold and late." Clay soil?, as a rule, were well supplied with all tbe necessary plant foodß, and as such very fertile, but they did not always possess the essential texture or mechanical for healthy plant growth. They were possessed of one great property which must always be borne in mind, ard that was what was shown ss tbe "fl.cculation" of the particle?, brought about by the addition of various eubstances to the soil, or by propsrly applied tillage. The whol? cause of the defective texture ot these sails was the fineness uf the particles. Securing a good mechanical texture was the whole key to tbe working of heavy sons. Most of them must have seen the marked improvement effected 011 heavy patches by the addition of lime or stable manure. Tillage bad exactly the same effect when applied at the right time—when the land was neither too wet nor too dry, particularly tbe former. When drainage was not defective, clay or heavy soils generally carried late feed, but large quantities of it. It waß better for tbe fallowing to be done late rather than done wet. The soils were very liable to develop a hard pan at the depth of ploughing, thus making them more impervious to roots, and to water. It was a wise practice therefore, never to plough them twice running at the Bame depth. They should be cultivated [after every rain with either scarifier or harrow, so that they never had a distinct crust on the surface. These cultivations, like the ploughing, must not be done while the ground was too wet. As. one of the texture troubles was that ths surface ran together, they should not be worked down too finely on the surface right up to seeding time. Being, as a rule, rich in plant food, they should be cropped more often than the lighter, but aa th.-y- become deficient in organic matter, some of the crops sLoull be for stock. In that connection he suggested the following arrangements of crops:— Bare fallow, wheat, barley, rape; bare fallow, wheat cats rape; bare tallow, wheat oats, with ryegrass, ryegrass. As the mechanical condition troubles arose through lack of lime very often, lime should be applied, either in email quantities every seeding (3-5 cwt to acre) or else a ton per acre once every four or five years, The lime should be applied always about a fortnight before the B«ed was put in.

LOAMS. Loamy soils were very hard to distinguish, as they were so far from being uniform in type. they were about midway, so tar aa phjiscal characters went, between clay and sand, but some of course trailed off into sandy loams on one extreme, and heavy loams on the other. Other loams again might just aa well be termed calcareous soils. They were often described as having the good qualities of all the other types, the bad ones being counteracted by the presence of their opposites. They wer« generally Btocked with all the necessary available plant food and had good natural mechanical conditions, so that practically all plant* which the climate permitted would grow well in them, and bacterial action took place nith the greatest of ease. They were good soils fur teed, which was eatly and abundant and f first-class quality. Most alluvial soils, ths fertility of which was proverbial, were included in this class. These soils were generally too good for the ordinary practice of bare fallow wheat, and he suggested to those who wished to mi>ke the most out of tbeir land in the shortest time that a better practice would be to bare fallow, wheat, barely, but as this class of farming was no good to the individual farm nor to the country as a whole, stock should be run in conjunction, and then the cropping should be:— Bare fallow wheat, pasture (pasture to have rape, oats, or some supplementary feed on it), or bare fallow, wheat, barley, pasture. CALCAREOUS SOlliS.

These were also hard to deiiae, as they varied widely, bJtb as regarded the percentage of lime and tluif mechanical condition. The proportions of lime range from 5 per cent to 60 per cent, and their consistedcy from the marls, which were more or less sticky when wet, to whit might he termed calcareuus. In South Australia most ot the calcareous soils were charactfeiUd by the presence either cf large hard limestones or else concentrations of small roundish stones. Some of these soils are v eiy lertilf, depending, bs a rule, on the proportion uf the fine soil constituents present; but others again were little better than the sandy soils. On the whole, hoxever, tb;y were very fair soil* for cereal growing. Jhe real marls (clayey-limey soil?) were comparatively rare here, so with the calceious soils other than for the stones present there were no serious cultural difficulties. Generally they could be worked when fairly wet without drying into clods, and in mo3t were heavy enough not to drift. As most of them were not exceptionally fertile, they should rot be overcropped, and should be woiked in conjunction with stock to which they were well suited, because uf the sweet, healthgiving food they produced. They were well adapted ti growing lucerne to be fed off, even though th:y dried out quickly; at the same time, the lucerne was very suitable to help build up tbe soils. He suggested, as tor sandy soils, that they should not be cropped too often, but treated under the following rotationßare fallow, wheat with lucerne, lucerne, lucerne, lucerne, whin profitable returns would be obtained, ai well as an improvement in the eoils, and more interest in the work. The rotation bare fallow, wheat, barley, pasture, pasture, wotild also be found profitable,