The reduction of manuring to an exact science proceeds apace, but a good deal of water will run under the Forth Bridge before the average cultivator has made up his mind that it is worth while to look twice at a manure heap.
There is no class more difficult to influence than that which has secured a certain result by a certain course of procedure. "Leave well alone" is its motto. It is not a bad one, I admit, but I should not agree to leave well alone when, by giving it up, better could be done. The cry is on all-fours with such old and crusted ones as "Slow and sure" (as if swift and sure were not far better); "A bird in the hand's worth two in the bush" (is not a bird in each hand superior to either?), and so forth.
Admitting that the man who takes refuge behind a series of old saws is difficult to dislodge, it by no means follows that it is not worth while to make the attempt. If we cannot catch him, we can at all events build blockhouses of hard, well-proven fact around him, so that his movements may be hampered, and he may work less direct mischief.
Of the two errors, it is easier to give too much manure than too little, consequently there is an appalling waste of good material going on in our gardens year by year. Moreover, as it is easier to give manure at the wrong time than the right, it follows as a natural sequence that most of our manuring is done at the wrong time.
The majority of people get into a way of thinking that the truth about manuring lies in the comparative merits of artificials versus dung. That is the point which would rise to the minds of most if they were asked to state the most important ground of debate. It is a consideration, to be sure, but since a harmonious and economical manuring system must inevitably bring into use both classes of fertiliser, it follows that the problem of finding it cannot be so ved by setting up one against the other, and seeing which can be the more quickly demolished by hard pummelling.
I have said that it is not only common to use too much manure, but to apply it at the wrong time. To take the case of Peas, as an example, the average cultivator would, if he used only one class of manure (and that dung), use three or four times as much of it as is wanted. On the other hand, if he used both dung and artificials, he would put the former on in spring, and the latter in late spring or early summer, whereas the former should be used in autumn and the latter in late winter.
In tackling a big, practical problem I must, of course, guard against enunciating a cultural fallacy for the sake of securing a literary antithesis. Let me, therefore, examine the position. We manure land, not for the purpose of putting out of sight a certain quantity of dung, but for securing a crop; therefore, the primary consideration is not what we put into the ground, but what we take out of it. We might bury one load of dung in a square rod of ground, or we might bury two, but the measure of our wisdom would not be estimated by that: it would be calculated according to the excellence of the crop. This is premiss No. 1.
A plant is supported by the food which its roots take up in a liquid form, and that food is prepared for it by a very remarkable culinary staff, termed nitrifying organisms. The process of "cooking" is called nitrification. If the kitchen staff is large and efficient the plant is well fed; if weak, the plant is badly nourished. The nourishment of the plant, therefore, does not depend upon the amount of raw food material which is put into the soil, but in the strength of the cooking staff. That is premiss No. 2.
As the cooking staff is of at least equal importance to raw food, measures must not only be taken to increase the food supply, but to strengthen the staff of cooks. That is premiss No. 3.
Now we come to ways and means. The method of putting food into the soil - one method, any way - we all know; but methods of adding to the staff of cooks we do not always know.
The practical cultivator long ago found himself face to face with a rather curious phenomenon. He manured his soil, and improved his crop. He manured his soil more, and got a still better crop. He manured even more heavily, and then, instead of getting a heavier crop in the same proportion as he had before, he got a smaller crop, and one not so healthy. He fell into a way of speaking of ground which had got into the condition of refusing to yield better crops after a certain point as "manure sick.''
What had happened was this: He had crammed the larder with food, but had not increased his staff of cooks, who were overworked in consequence. Under the unwholesome conditions present in the soil they dwindled instead of increasing, and so things went from bad to worse.
The cooking staff in the soil can be increased by the provision of warmth and air. An inert, hard-grained, brick-in-summer-and-paste-in-winter soil contains little warmth and little air, consequently few cooks. Break it up, turn it, expose it, and both warmth and air penetrate; then the cooks troop in, tie on their aprons, and set to work. In many soils there is abundance of raw material for them already existing, and more need not be added. I have observed with much interest how readily a soil, neglected for years, half-tilled, unmanured, and altogether impoverished, has responded to tillage alone, giving excellent crops with very little manure. To attempt to renovate neglected soil by simply cramming in manure is wasteful and unscientific.
The plan which the cultivator adopts to cure manure-sick soil is to add lime. It is an old plan. The lime acts on the manure, and sets free its food constituents, so that it really feeds the crop. Yes, liming is good, but it always strikes me as a very cumbrous and roundabout way of keeping healthy to first of all ignore the rules of health and then swallow medicine to remedy the ill effects of neglect. Why not learn the rules of good health first, and observe them?
To give too much manure, and then have to add lime to put matters right, is surely a very clumsy way of going to work.
The application of the ideas of manuring herewith thrown out could, doubtless, be made with satisfactory results by many intelligent cultivators, but it will, perhaps, be most satisfactory to point them by practical details, followed by hints on each particular crop.
I have said that the manuring problem is not merely the issue between natural and artificial manures. As a matter of fact, both provide the same constituents. Good crops of vegetables can be obtained with either or both. The man who declares that only natural manure is of any use, and he who says the same of artificials, are both in the wrong. Some crops do particularly well with natural manures, others seem to thrive admirably with artificials, but many crops do best with a judicious blend of both. What is wanted is exact knowledge.