THE RURAL WORLD.

King Country Chronicle, Volume VI, Issue 462, 4 May 1912, Page 6

THE RURAL WORLD.

LIVING AND DEAD SOILS

"'Soils without bacteria ars dead soils, and as such unfit to support profitable crops," Dr J. G. Lipman, director o£ the New Jersey Experiment Station and professor of bacteriology and soil fertility, New Jersey Station College, supplies much information to back up this statement. Every farmer, he asserts, should know something of the food that bacteria must have and of the conditions required for the proper utilisation of this food. To the average man it is evident that a heap of fresh manure will in time become darker in colour, and will shrink in size; that manure, added to the land, "rots" and disappears; that the bodies of buried animals, or crops, of clover, vetch or rye, ploughed into the soil, vanish in time and become an indistinguishable part of the soil itself. Yet it is not as evident to him that the disappearance Of these substances is the result of vital activities. He fails to realise that the universal process of delay may be stupped by preventing the growth of bacteria as is actually done in canning factories. In these the food is heated to destroy the bacteria, and is then sealed to prevent the entrance of living germs. It is for thia reason that a can of tomatoes, properly sterilised and sealed, will keep indefinitely, whereas the same tomatoes, after the can is opened, will ferment and spoil within one or two days. To the average man it is not evident that the process of fermentation is never suspended in the soil, except when the latter is frozen. He | often fails to realise that abundant, but not excessive, moisture, a favourable temperature, and a plentiful supply of air stimulate the activities of soil bacteria. Neither does he realise that a soil may contain a relatively large amount of partly decomposed vegetable and animal matter (humus), and yet may fail to offer enough food for "the vigorous growth of useful bacteria. Let it be remembered in this connection that soils are formed slowly out of weathered' rock, that they become gradually richer in available plant food and richer in vegetable matter and bacteria. The day comes at last when these virgin suils make the acquaintance of the farmer and his implements of tillage. And as the furrows are turned, as thfl soil is mellowed, and the air and water and sunshine are made to mingle with it, the bacteria are stirred to feverish activity. They have food a-plenty, and they attack vigorously the plant and animal materials that had been accumulating, perhaps throughout many centuries as prairie sod and forest mould.

But after a time the lean years come, and the farmer wonders why this land is growing le3S and less productive. The soil that was once dark in colour, and mellow to the touch, as if instinct with life, has become lighter in colour and lifeless to the touch. Why this change; and what of the bacteria that were so generously fed m the newly-established fields? An answer to these questions may be found in the history of every agricultural country. It is the vegetable matter decaying rapidly at first, and then more and more slowly, until the residues finally become so inert, so resistent to decay, that the bacteria fail to secure enough food, and come upon a period of starvation. For, after all, it is not so much the quantity of humus in the soil, but the quality of it, that regulates the growth and activity of bacteria, It is surprising what enormous quantities of plant food are present in many so-called "run-down" or "worn-out" soils. Yet, notwithstanding the abundance of plant food, the seed do not yield profitable returns. There is not enough ferment a ion in these soils, the per fee t bacterial machinery is lacking, and the acids and other chemical products of fermentaton are not abundant enough ton provide for a rapid breaking down of the rock particles, and the formation of available phosphoirc acid and potash. But if these "wornout" soils receive more or less regular applications of fresh manure, or of green clover, opeas, or vetch, and the bacteria will find again enough digestible food in them, and the abundant harvest will come back slowly but surely. In this wise many of the abandoned farms in the east have returned to their old prosperity, just as the soils of Europe (after a period of decline) have reached a of intense cultivation.

In considering the quality of humus serving as food for bacteria, it should be remembered that it should not be too acid. Everything being equal, the greater the proportion of nitrogen in fresh vegetable and animal matter the more readily it will be attacked bv bacteria. For this reason horse manure will ferment more rapidly than cow manure, and clover, rape, vetch peas, etc,, will ferment more readily than rye, maize, or wheat. The legumes are, therefore, soilenriching crops, not merely because they add nitrogen to the land, but because they are an acceptable food to decay bacteria, and ferment in a more intensive mannre than rye or wheat. As fermentation proceeds, various acids are formed, and these may accumulate to a sufficient extent to hinder the further growth of the bacteria. Hence an abundance of lime is essential for keeping the soil sweet, and the bacterial activities at their maximum. Furthermore, bacteria are, after all, minute plants, and, like higher plants, require available phosphoric acid and other mineral substances for their vigorous growth. On account of this fact, ths use of commercial fertilisers (together with the green manures mentioned above) will provide for a more rapid improvement of the land. It is evident from the foregoing statements that the secret of high productivity and intensive cropping lies in intensive fermentation — that is, bacterial activity in the soil. Suils whose bacteria are well fed will also support crops that are well fed. But since it is-not possible to have well-fed bacteria in soils poor in humus, it follows that in the

long run commercial fertilisers alone are not sufficient for maintaining soils permanently fertile, and that permanent fertility can be assured only when commercial fertilisers are supplemented either by annual manures or by green manures.

ROOTS FOR FARM ANIMALS. If we compare the food value contained in a ton of root 3 '.vith the food value of any other class of feed, we will find it is exceedingly cheap. If we compare the effects of feeding these roots, it is probably the cheapest stuff we can grow; not to make it the main forage crop on the farm but to make it one of the principal. It is up to every one of us, therefore, to interest ourselves in root growing. Every class of live stock, grown or bred on the farm, will be benefitted by the use to a greater or less extent of the different class of roots.

There is no class of animal that seems to be so much benfitted by the addition of a small amount of roots to its ration as the horse. It keeps his hair in condition and he seems toj make better use of his food when there are roots in the ration. We have tried experiment and we find every time, that while mangels and turnips will be taken with more or less pleasure by the horse the carrot is the most acceptable. The great objection to the arrot is its poor keeping quality. When it comes to the cow or steer there is no class of animal that welcomes so keenly, the addition of a small amount of roots to their feed. The value of roots to a cow can scarcely be overestimated. When we know that about 90 per cent, of the root is water, leaving only 10 pounds in 100 of dry matter we might say it is rather an expensive way of watering cattle; still that 10 pounds seems to have a mo3t beneficial effect on the animal whether for milk production, or beef production, and the addition nf roots to the ration diminishes ihef quantity of necessary, and that is an important point where we do not raise enough grain foods for ration purposes. Sheep have been developed on roots. The home of the sheep is Europe. The home of the sheep in Europe is most certainly the British Isles. No farmer there thinks of trying to farm without roots. Hence we find the average pheep does nut know anything that will suit it so well as the addition of a considerable amount of roots to its ration. The root that seems to suit the sheep best is the turnip. Turnips grow best in the home of the best mutton, and they grow in tremendous quantity. I have seen as high as 45 to 50 tons of turnips to the acre growing in Southern Scotland. There they constitute the cheap part of the ration and have the effect of developing carcase of mutton that commands a high price in England, the best market in the world. —J. H. Grisdale.