THE FARM.

Kaipara and Waitemata Echo, 3 July 1914, Page 7

THE FARM.

A LOSS-, PREVENTED IS A PRO-

FIT MADE

The greatest losses on a farm are very often the unnoticed ones. They are unnoticed because they are not apparent on the surface. One of the most serious of these losses is lime. Three wide gates for ever stand open on our farms, and through these gates the valuable lime in the sdil is ceaselessly going, never to return unless brought back in the farmer's dray.

What are these gates, and why are they left open ? Is it possible to keep them closed ? We shall answer' these questions to the best of our ability. The first of these gates is the crop ; and since a farmer cannot live unless he markets his crop, be it milk, live stock, grain, or fruit, this gate cannot and must not be closed. The second gate may be called drainage, and this may be kept closed, and certainly should for a great part of the year. The third gate is called "artificial fertilisers," and should only be left open under exceptional circumstances.

We often wonder whether farmers realise' when they cart away their crop, whatever it may be, that in addition to a certain amount of fertility they are also carting away a considerable quantity of lime. There is nothing that a farmer can sell off his farm that does not contain it. (He may possibly remember to replace the nitrogen, the phosphorus, the potash, but how about the lime?

, Is it any wonder that this necessary substance should be conspicuous by its absence on so many of the dairy farms when this regular—and for the most part unreplaced—loss is going on all the time ? The loss going on through the second gate, called "drainage,"' is a . very serious and constant one. The heavier the rainfall in a district,-the greater the loss. Water can take up >a considerable quantity of lime, and in porous volcanic or sandy soil the amount of water- that passes right through and away in the course cf twelve months is considerable. It has been estimated that with, every 100,000 gallons of water nearly 2 cwt. 'of lime will pass away. In looking for a remedy it is very' clear that wc must not interfere with or injure the structure or physical condition of the soil, because good dmi'ia/re is one of the first conditions nercasary for successful agriculture. It is fortunate that this loss is grea*?r on cultivated lands than on pastures. It occurs most in the winter, 'wl:eu the rainfall is greatest tin* the growth is least. Plant food of all ; kinds gradually become soluble, 'as it does so is liable to be cariiod ; away in the drainage water if there are not crops growing there to use it up. The growing plants also use a great deal of water, leaving less to pass away ; so in a double way tn*y reduce the iraete. It may be asked whether there is not still a loss when thei plant Uses the lime. There would be, of course, if the whole plant were cut and carted away from the farm, but not so when it is

eaten by the stock, for the bulk goes back to the soil in the form of manure. The lime then is placed upon the surface, and is available for shallowrooted as well as deep-rooted plants

When we come to consider the third gate—perhaps the greatest avenue of loss of the soil's lime and other elements of fertility that there is*—we shall perhaps be able to throw light upon several curious and perplexing changes- that come over soils. We have called this third gate "artificial fertilisers," and before we go any further we would like to say that we have nothing hard or condemnatory to say about "artificials." They are most necessary., We do not deride their use, but rather their abuse.

'This, then, is the widest gateway of all, and it stands for ever open on the farm where artificial manure is used in fair quantities. Some forms of artificials are. tremendous gluttons for lime—or to be more correct, the sulphuric acid used in their manufacture is the glutton. It is, after all, obeying the great chemical law of combination. An acid must combine with a base if it happens to be there to combine with ; so this particular acid combines with the carbonate .of lime in the soil. If there is not a very large supply of lime in the soil it does not require a great many applications of superphosphate—or sulphate of potash—to exhaust it, and any good which those manures may have effected would be largely counterbalanced by hhe deterioration in the crops owing, to the absence of lime. Of course, these injurious results are not to be seen! where the manure is first put on ; it may take several seasons to bring them out prominently. All the acid, for instance in super is in combination with lime." The resulting product being sulphate of lime, or gypsum. The tendency of gypsum is to make a soil acid, because chemical changes are constantly going 01 in every soil, one element combining with another to make a third substance ; and in the process of time the gypsum has 'parted with all its lime and the sulphuric acid is left. This is the reason why light volcanic lands, deficient naturally in lime, have a tendency to produce finger and toe disease in turnips after several applications of superphosphates,. A dense growth of sorrel comes for the same reason.

If a good dressing of superphosphates is put on to a field, a proportion of the- phoKphoric acid is certain to combine with the lime in the soil if there is any there, the result being phosphate of lime. Thtis does not mean, of course, that the lime in this instance is finally lost to the

soil, but it is certainly put under lock and key for the time being, and is unable to prevent 'or neutralise any acidity that may develop in the soil.

To avoid as far as possible these troubles on light lands deficient in lime it is necessary to use superphosphate with great moderation,and not repeatedly on the same land. It is best used in conjunction with a manure like basic slag, in varying proportions of from one-to-two to half-and-half, mixed just before being sown over the field.

Super can be advantageously and safely used alone in the event of the field having been dressed with lime some little time before. But apart altogether from the tendency of superphosphate to encourage acidity in soils, the gypsum (sulphate of lime) has the Effect of spoiling the texture and physical i condition of soils by. making them claggy and more difficult to work up into a seed bed. Since, therefore, there is this ceaseless loss of lime going on in tbe soils, and through so many channels, so to speak ; and since, too, this ! loss is difficult to check, and in ic«ny I cases cannot wholly be prevcpird ; phow necessary for the farme-; to malm a point of keeping up the lime ! content of his farm at all costs. No farm can remain productive Nif the lime content is allowed to run down say, 1 per cent., which is equi j valent to about 30,000 lb. per acre |in the upper foot of the soil. As a '. matter of fact, an examination of | the soils of the world shows that the ! percentage of lime in some soils runs ' , as high as 50 per cent. ' > Liming can be done in the autumn and winter months, when the great pressure of dairy work is over, and it is not too much to say that the money so spent would bring the farmer in a handsome return for 9 seve- | ral years after. Up to 500 lb. of lime can be put on light land, and up to 1 ton on heavy. It should be 'well incorporated in the soil.—"New Zealand Dairyman."