Talks on Manures Part 19

These are the facts. Let us not quarrel over them.

CHAPTER XXIV.

THE CHEAPEST MANURE A FARMER CAN USE.

I do not know who first said, "The cheapest manure a farmer can use is--clover-seed," but the saying has become part of our agricultural literature, and deserves a pa.s.sing remark.

I have heard good farmers in Western New York say, that if they had a field sown with wheat that they were going to plow the spring after the crop was harvested, they would sow 10 lbs. of clover-seed on the wheat in the spring. They thought that the growth of the clover in the fall, after the wheat was cut, and the growth the next spring, before the land was plowed, would afford manure worth much more than the cost of the clover-seed.

"I do not doubt it," said the Deacon; "but would it not be better to let the crop grow a few months longer, and then plow it under?"

"But that is not the point," I remarked; "we sometimes adopt a rotation when Indian-corn follows a crop of wheat. In such a case, good farmers sometimes plow the land in the fall, and again the next spring, and then plant corn. This is one method. But I have known, as I said before, good farmers to seed down the wheat with clover; and the following spring, say the third week in May, plow under the young clover, and plant immediately on the furrow. If the land is warm, and in good condition, you will frequently get clover, by this time, a foot high, and will have two or three tons of succulent vegetation to turn under; and the farmer who first recommended the practice to me, said that the cut-worms were so fond of this green-clover that they did not molest the young corn-plants. I once tried the plan myself, and found it to work well; but since then, I have kept so many pigs and sheep, that clover has been too useful to plow under. But we will not discuss this point at present.

"What I wanted to say is this: Here we have a field in wheat. Half of it (A) we seed down with 12 lbs. of clover-seed per acre; the other half (B) not. The clover-seed and sowing on A, cost, say, $2 per acre. We plow B in the fall; this will cost us about as much as the clover seed sown on A. In the spring, A and B are both plowed and planted to corn.

Now, which half of the field will be in the cleanest and best condition, and which will produce the best corn, and the best barley, or oats, afterwards?"

"I vote for A," said the Deacon.

"I vote for A," said the Doctor.

"I vote for A," said the Squire.

"I should think," modestly suggested Charley, "that it would depend somewhat on the soil," and Charley is right. On a clean, moderately rich piece of light, sandy soil, I should certainly expect much better corn, and better barley or oats, on A, where the clover was grown, than on B.

But if the field was a strong loam, that needed thorough cultivation to get it mellow enough for corn, I am inclined to think that B would come out ahead. At any rate, I am sure that on my own farm, moderately stiff land, if I was going to plant corn after wheat, I should _not_ seed it down with clover. I would plow the wheat stubble immediately after harvest, and harrow and cultivate it to kill the weeds, and then, six weeks or two months later, I would plow it again. I would draw out manure in the winter, pile it up in the field to ferment, and the next spring spread it, and plow it under, and then--

"And then what?" asked the Deacon. --"Why the truth is," said I, "then I would not plant corn at all. I should either sow the field to barley, or drill in mangel-wurzel or Swede-turnips. But if I _did_ plant corn, I should expect better corn than if I had sown clover with the wheat; and the land, if the corn was well cultivated, would be remarkably clean, and in fine condition; and the next time the land was seeded down with clover, we could reasonably expect a great crop."

The truth is, that clover-seed is sometimes a very cheap manure, and farmers are in no danger of sowing too much of it. I do not mean sowing too much seed per acre, but they are in no danger of sowing too many acres with clover. On this point, there is no difference of opinion. It is only when we come to explain the action of clover--when we draw deductions from the facts of the case--that we enter a field bristling all over with controversy.

"You have just finished thres.h.i.+ng," said the Deacon, "and for my part, I would rather hear how your wheat turned out, than to listen to any of your chemical talk about nitrogen, phosphoric acid, and potash."

"The wheat," said I, "turned out full as well as I expected. Fourteen acres of it was after wheat, and eight acres of it after oats. Both these fields were seeded down with clover last year, but the clover failed, and there was nothing to be done but to risk them again with wheat. The remainder was after barley. In all, there was not quite 40 acres, and we had 954 bushels of Diehl wheat. This is not bad in the circ.u.mstances; but I shall not be content until I can average, taking one year with another, 35 to 40 bushels per acre. If the land had been rich enough, there would unquestionably have been 40 bushels per acre this year. That is to say, the _season_ was quite capable of producing this amount; and I think the mechanical condition of the land was also equal to it; all that was needed was sufficient available plant-food in the soil."

"I can see no reason," said the Doctor, "why you may not average 40 bushels of wheat per acre in a good season."

"The field of 14 acres," said I, "where wheat followed wheat, yielded 23 bushels per acre. Last year it yielded 22 bushels per acre; and so we got in the two years 45 bushels per acre."

This field has had no manure of any kind for years. In fact, since the land was cleared, 40 or 50 years ago, I presume that all the manure that has been applied would not, in the aggregate, be equal to more than a good crop of clover-hay. The available plant-food required to produce these two crops of wheat came from the soil itself, and from the rain, dews, and atmosphere. The land is now seeded down with clover, and with the aid of a bushel or two of plaster per acre, next spring, it is not improbable that, if mown twice for hay next year, it will yield in the two crops three tons of hay per acre.

Now, three tons of clover-hay contain about 33 lbs. of phosphoric acid, 90 lbs. of potash, and 150 lbs. of nitrogen.

The last crop of wheat, of 22 bushels per acre, and say 1,500 lbs. of straw, would contain:

In the grain. In the straw. In total crop.

Phosphoric acid 11 lbs. 3 lbs. 15 lbs.

Potash 6 " 9 " 16 "

Nitrogen 23 " 9 " 32 "

It seems very unkind in the wheat-plants not to give me more than 22 bushels per acre, when the clover-plants coming after will find phosphoric acid enough for 40 bushels of wheat, and potash and nitrogen enough for nearly 100 bushels of wheat per acre. And these are the three important const.i.tuents of plant-food.

Why, then, did I get only 22 bushels of wheat per acre? I got 23 bushels on the same land the year previous, and it is not improbable that if I had sown the same land to wheat again this fall, I should get 12 or 15 bushels per acre again next year. But the clover will find plant-food enough for 40 bushels of wheat.

"There is not much doubt," said the Deacon, "that you will get a good crop of clover, if you will keep the sheep off of the land this fall.

But I do not see what you mean by the clover-plants finding food enough for 40 bushels of wheat, while in point of fact, if you had sown the field again to wheat this fall, you would not, as you say, probably get more than 12 or 15 bushels of wheat."

"He means this," said the Doctor. "If he had sown the land to wheat this fall, without manure, he would probably not get over 15 bushels of wheat per acre, and yet you both agree that the land will, in all probability, produce next year, if mown twice, three tons of clover-hay per acre, without any manure.

"Now, if we admit that the clover gets no more nitrogen from the rain and dews, and from the atmosphere, than the wheat will get, then it follows that this soil, which will only produce 15 bushels of wheat per acre, does, in point of fact, contain plant-food enough for 40 bushels of wheat, and the usual proportion of straw.

"The two crops take up from the soil as follows:

Phosphoric acid. Potash. Nitrogen.

15 bushels wheat and straw 10 lbs. 11 lbs. 22 lbs.

3 tons clover-hay 33 " 90 " 150 "

"These facts and figures," continued the Doctor, "are worth looking at and thinking about. Why can not the wheat get as much phosphoric acid out of the soil as the clover?"

"Because," said the Deacon, "the roots of the clover go down deeper into the subsoil than the roots of wheat."

"That is a very good reason, so far as it goes," said I, "but does not include all the facts. I have no sort of doubt, that if I had sown this land to wheat, and put on 75 lbs. of nitrogen per acre, I should have got a wheat-crop containing, in grain and straw, 30 lbs. of phosphoric acid. And so the reason I got 15 bushels of wheat per acre, instead of 40 bushels, is not because the roots of wheat do not go deep enough to find sufficient soluble phosphoric acid."

"Possibly," said the Doctor, "the nitrogen you apply may render the phosphoric acid in the soil more soluble."

"That is true," said I; "and this was the answer Liebig gave to Mr.

Lawes. Of which more at some future time. But this answer, like the Deacon's, does not cover all the facts of the case; for a supply of soluble phosphoric acid would not, in all probability, give me a large crop of wheat. I will give you some facts presently bearing on this point.

"What we want to find out is, why the clover can get so much more phosphoric acid, potash, and nitrogen, than the wheat, from the same soil?"

MORE ABOUT CLOVER.

The Deacon seemed to think the Doctor was going to give a scientific answer to the question. "If the clover _can_ get more nitrogen, phosphoric acid, and potash, from the same soil than wheat," said he, "why not accept the fact, and act accordingly? You scientific gentlemen want to explain everything, and sometimes make confusion worse confounded. We know that a sheep will grow fat in a pasture where a cow would starve."

"True," said the Doctor, "and that is because the cow gathers food with her tongue, and must have the gra.s.s long enough for her to get hold of it; while a sheep picks up the gra.s.s with her teeth and gums, and, consequently, the sheep can eat the gra.s.s down into the very ground."

"Very well," said the Deacon; "and how do you know but that the roots of the clover gather up their food sheep-fas.h.i.+on, while the wheat-roots eat like a cow?"

"That is not a very scientific way of putting it," said the Doctor; "but I am inclined to think the Deacon has the right idea."

"Perhaps, then," said I, "we had better let it go at that until we get more light on the subject. We must conclude that the wheat can not get food enough from the soil to yield a maximum crop, not because there is not food enough in the field, but the roots of the wheat are so const.i.tuted that they can not gather it up; while clover-roots, foraging in the same soil, can find all they want."

"Clover," said the Deacon, "is the scavenger of the farm; like a pig, it gathers up what would otherwise be wasted."