ON CLAY AND CLAY SOILS, WITH THEIR CULTIVATION.

Daily Southern Cross, Volume XXII, Issue 2829, 20 August 1866, Page 4

ON CLAY AND CLAY SOILS, WITH THEIR CULTIVATION.

' (FOB THE " DAILY SOUTHERN CROSS."') Tiir word "soil" couveys different meanings to dilicront minds. In the agricultural sense, soil is the ordinary medium by which trees and vegetation in general are supported, and by means of w hich manures are applied for the benefit of growing crops. The ground we tread on is our native or adopted soil. The ground a fanner tills by plough and harrow he considers as the true soil. A pii' ely clay soil, when fully moistened, feels greasj', and can be moulded into any shape or form. Clay retains water on its surface, and absorbs large quantities, for which it has a strong affinity. The temperature is low, it parts with water slowly ; but when dry clays crack, they become hard and form into lumps, which require much labour to break them ; when neither wet nor dry, clays become tough, harden with drought, soften again with rains. Hence, clay soils are difficult to farm — more difficult than most other soils — *nd for some time require both money, manure, and extra strength of horses, bullocks, or steam, to bring them into workable condition. But when once properly farmed, they are valuable for their capabilities of growing luxuriant crops through a series of years, which would totally exhaust your coveted light volcanic or other soils; and the grain produce is of superior quality. The Carse of Gowrie is a notable example. Carse lands are deep horizontal depositions of alluvial or diluvial clays, and generally include a large extent of country, but they are not adapted for the cultivation of grasses to any extent, or rearing of live stock. They are capable, however, of growing all kinds of grain— and grain, wheat especially, of the best quality. Lime enters freely into the system of management practised by the Carse farmers. Carse farms, being wholly arable, always let at a high figure per acre. Besides Gowrie, the Carses of Stirling and of Falkirk are notable districts for possessiug fertile soils of a clay nature, and famous for the excellence of their management and the constant quantity and qualityof the grain or pulse grown on their areas. But apure clay is not often found, and whereaclayloam can be got it should be preferred, as a more useful and valuable soil. Clay loams are more easily tilled, and will pulverise with little trouble. Loam maybe either clay or sand mixed with a considerable proportion of decomposed vegetable matter, as two-thirds of clay or two-thirds sand, are held to constitutethe character of that soil, q In many parts of this province, as also to the west or north-west of the capital, a hard indurated sub-soil is too common, and a very bad nature of a sub-soil this is reckoned. In Auckland province will be found white clays very much inferior to the yellow, and in somepar^s ferruginous clays, or clays mixed with iron. Both are inferior in quality, and both mutt have' skill and capital liberally bestowed to bring them into fertile condition. The white clays hold various proportions of sand. If they do not form lumps like Carse clay, it is because the poor sand destroys cohesion in the clay. Notwithstanding that we thus read of clay soils forming the superficial stratum, no inconsiderable worth of such land will depend on the sub-soil — a consideration too often wholly overlooked. Give us a good sub-soil, say the Scottish farmers, and we will make a good super-soil. If the siib'-soil is formed of rock, there is an end to sub-soiling. It may consist of the same components as the soil itself, or it may be different. At any rate the subsoil of any land produces very decided effects on the state of soil above it. A retentive sub-soil on a porous super-soil may work very well, and inversely, better. When both are clay, the maximum of retentiveness is attained, and the land pronounced wet. Some sub-soils may, however, be so retentive that gravelly or sandy lands would be termed wet also. Rock generally is dry, if not on too low a level. We have stiff soils, light soils, wet soils, dry soils, rich soils, poor soils, deep and shallow, white, and black, and grey, and brown, and red ; and hungry and grateful, kindly and ungrateful, inert and sharp, and so on. Now, the colours of soil have powerful influences on the absorption of the sun's heat, or calorific rays. The difference of temperature between a white sand and a rich black was found to be not less than 13* Fah. in favour of the black. Again, dark-coloured soils radiate the heat more quickly than the lighter shades, and sand cools more slowly than clay. If a sandy soil retains heat for three hours after sundown, and a clay for two hours, a black or brown vegetable soil will retain it only one hour; but then, it begins to absorb dews all the sooner, and wherever is humus there is the greatest degree of absorption. Sand absorbs very little. Hence iv dry seasons, crops or grasses on sandy soils severely suffer, while those on lands rich with humus and manures generally bring their crops to maturity. Humic soils have also the strongest affinity for oxygen ; clays hold the second place, and sands the last. Oxygen combines with various organic matters of the soil in a chemical manner, forms with these new combinations, and more carbonic acid is attracted from the atmosphere. The inorganic earths will also take up oxygen, but only few new combinations are formed, and warm temperatures above 55* increase the powers of absorption. This oxygenating is what is meant by aerating new ground, turning it up to atmospheric action, when the winds and rains also perform their parts, and pulverization is promoted. Without pulverizing, no soils having vegetable matter and adhesion of particles will ever form they impalpable powder so necesary to vegetation. This pulvis consists of inorganics, and animal and vegetable substances, all which contribute to the desired end, fertility, which may be j considered hereafter, as we must get our land ready j and dry before the prime sources of fertility —manures — can be applied with due advantage to the soil, and profit to the owner. If any operation of a farmer deserves to be done better than another, it is ploughing. In most parts of the province settlers do not appear to be very particular in the modus or manner of ploughing. Bad ploughing and worse harrowing makes the worst kind of farming. Many of the teams are too weak for their work, and horses pull in the "Draw you this time— l drew last" sort of way, making the yoke a reciprocating sort of never even balance. Many of the ploughs are scarcely thirdrate, and many of the ploughmen no rate at all, and wholly ignorant of the bwt way to adjust the irons for the work. There is much in this adjusting or trimming of a plough. Well- regulated ploughs should almost be held by the forefingers and thumbs they go so easily. It is torture to see a stout fellow leaning with all his' weight on two stilts to keep the share from running over-deep ; sweating like a fireman ; while the poor animals tear away to overcome a resistance at least one-third more than ought to have been necessary for turning the furrows, if the plough had been properly trimmed and rightly conducted. Ho kind of measures or arrangements have been so eminently successful in training up good ploughmen as ploughing matches. "Voting men immediately feel an interest in the concern ; emulation is excited ; opportunities present themselves of seeing really good work, and a name on the prizelist crowns their ambition, and raises a reputation. Shallow ploughing is the practice in this province, a practice scarcely warranted by theory or science. Plenty of leas, where the grasses have been failing, are broken up with a depth of four inches furrow on an average — mere scratches, as these lands have been covered with hawksweed and many other -weeds ; so shallow ploughing will neither eradicate the weeds, nor raise a mould for future grass and clover seeds Six inches wide by nine inches broad are geometrical proportions, and, as a general rule, might be adopted as a standard. But what with shallow ploughing, pieces missed turning over at all, furrows thrown over one another, and so on, the work done iv remote country places, at least, will not be entitled to any premiums, unless any should be ever given for the worst ploughed acres. Which reminds me of an anecdote, neither recorded by Walter Scott, nor Dean Ramsay, nor yet the Laird o Logan, nor any other collectors of Scottish story. "'Twas about the end of last century, when lairds began to wear their skeins or daggers after the Disarming Act had become obsolete. The Laird was walking behind one of his ploughmen, bestowing various admonitions on that menial about making better work, and one miss or baulk of several feet particularly merited censure. When opposite this faulty place at next round, the man took a very broad furrow, and throwing it on the baulk, observed, ' This covers that.' His master snatched off the ploughman's bonnet, and gars him a cut on the crown with his daggtr, then clapping on the man's bonnet, exclaimed, 'And this covers that.'" If similar discipline were permitted in this province, there would be more "scoring on the pate" than Falstaff scored for sack with his hostess of EastIf district ploughing matches were instituted, then much good would follow, not only to those districts, but to the whole province Those who would benefit, and wish to see good ploughing, should attend the ploughing matches of the Otahuhu Agricultpal Society, or those of the Papakura Association. . To plough well was the favourite maxim of Cato the Censor, and he well understood Roman fanning, as may be learned from his work De Re Rustica. . Thus much for good ploughing. Rainretentive field ought to be warptd up by the plough..-

The firht two fiiiiows. .lie laid one upon the other, anil the lest gatheied to them. By tins method a cvi vo of fiom mk to eight mclies radius can tlins be obtained, or a declivity of six to eight inches fiom top of ridge to bottom of the last furrow, which is j commonly called the water furrow, as it should be always kept open and clear of any earth or other obstruction to superfluous water. The breadth of ridges varies as the soil and rain -retentive power thereof ; eighteen feet is a very frequent size ; but if the field is rather wettish, then fifteen feet is to be preferred. When the breadth of ridge is twenty four feet, the ground is then too flat, or else requires a double gathering up, which process greatly impoverishes the land next all the water furrows, and is double toil and trouble in addition. The fifteen-feet ridge is, therefore, to be preferred, although twelve-feet wide ridges have had many practical advocates. When parallel and straight, they look rather pretty with their open furrows. This kind of ridges is admirably fitted for low-lying grounds which have very little declivity or inclina- 1 tion any way. We can see iv this province many, many acres of alluvial land without one ditch or water furrow, and as flat as a pancake. When rains like those of the 31st March, 1866, descend in superabundance, these flats become covered with water, irrigated as it were ; and indeed some of them invite the practice of irrigation, and admirable conveniences almost offer themselves for that excellent purpose, if it were possible to hammer irrigation ideas into the dry brains of many self-satisfied owners. But even in this case, it is a rule necessary to be observed in all irrigation operations that the land should be free from superficial, as from underground water, that is, there ought to be no excess of natural wetness on or in the land, to neutralise the effects of artificial irrigation. Ridges should be made to run north and south, if the dip of the ground will admit ; but whether or not, the ridges must be made in conformity with with the inclination, for all water ought to be carried off as a rule imperative, above any secondary advantages. As for trench-ploughing, it will be only waste of time and paper to propose it. Few farmers in this province are so far advanced as to trench-plough their fields. Trench-ploughing is done for one or two purposes, either to move a stiff or hard subsoil, which in this instance is not brought up but only loosened, or to deepen the supersoil by bringing up fresh earth which has been lying perhaps undisturbed since its first deposition. If the subsoil is good, theu much benefit will be derived from a deep ploughing. Twelve to fifteen inches is considered about the proper depth, and may be done by one strong plough, drawn by six oxen or bullocks, or by two ploughs drawn thus : the first by one pair of horses, and the second plough by four horses or bullocks, following the first.