TALKS ON MANURES A SERIES OF FAMILIAR AND PRACTICAL TALKS BETWEEN THE AUTHOR AND THE DEACON, THE DOCTOR, AND OTHER NEIGHBORS, ON THE WHOLE SUBJECT TEXT

heap on one of the sloping sides of the basin; with a horse and cart we drew to this heap, just as winter set in, every bit of manure that could be found on the premises, and everything that would make manure. When got all together, it made a heap seven or eight feet wide, twenty feet long, and three or four feet high. We then laid planks on the heap, and every day, as the pig-pens, cow and horse stables were cleaned out, the manure was wheeled on to the heap and shaken out and spread about. The heap soon commenced to ferment, and when the cold weather set in, although the sides and some parts of the top froze a little, the inside kept quite warm. Little chimneys were formed in the heap, where the heat and steam escaped. Other parts of the heap would be covered with a thin crust of frozen manure. By taking a few forkfuls of the latter, and placing them on the top of the “chimneys,” they checked the escape of steam, and had a tendency to distribute the heat to other parts of the heap. In this way the fermentation became more general throughout all the mass, and not so violent at any one spot. “But why be at all this trouble?”--For several reasons. First. It saves labor in the end. Two hours’ work, in winter, will save three hours’ work in the spring. And three hours’ work in the spring is worth more than four hours’ work in the winter. So that we save half the expense of handling the manure. 2d. When manure is allowed to lie scattered about over a large surface, it is liable to have much of its value washed out by the rain. In a compact heap of this kind, the rain or snow that falls on it is not more than the manure needs to keep it moist enough for fermentation. 3d. There is as much fascination in this fermenting heap of manure as there is in having money in a savings bank. One is continually trying to add to it. Many a cart-load or wheel-barrowful of material will be deposited that would otherwise be allowed to run to waste. 4th. The manure, if turned over in February or March, will be in capital order for applying to root crops; or if your hay and straw contains weed-seeds, the manure will be in good condition to spread as a top-dressing on grass-land early in the spring. This, I think, is better than keeping it in the yards all summer, and then drawing it out on the grass land in September. You gain six months’ or a year’s time. You get a splendid growth of rich grass, and the red-root seeds will germinate next September just as well as if the manure was drawn out at that time. If the manure is drawn out early in the spring, and spread out immediately, and then harrowed two or three times with a Thomas’ smoothing-harrow, there is no danger of its imparting a rank flavor to the grass. I know from repeated trials that when part of a pasture is top-dressed, cows and sheep will keep it much more closely cropped down than the part which has not been manured. The idea to the contrary originated from not spreading the manure evenly. “But why ferment the manure at all? Why not draw it out fresh from the yards? Does fermentation increase the amount of plant-food in the manure?”--No. But it renders the plant-food in the manure more immediately available. It makes it more soluble. We ferment manure for the same reason that we decompose bone-dust or mineral phosphates with sulphuric acid, and convert them into superphosphate, or for the same reason that we grind our corn and cook the meal. These processes add nothing to the amount of plant-food in the bones or the nutriment in the corn. They only increase its availability. So in fermenting manure. When the liquid and solid excrements from well-fed animals, with the straw necessary to absorb the liquid, are placed in a heap, fermentation sets in and soon effects very important changes in the nature and composition of the materials. The insoluble woody fibre of the straw is decomposed and converted into humic and ulmic acids. These are insoluble; and when manure consists almost wholly of straw or corn stalks, there would be little gained by fermenting it. But when there is a good proportion of manure from well fed animals in the heap, carbonate of ammonia is formed from the nitrogenous compounds in the manure, and this ammonia unites with the humic and ulmic acids and forms humate and ulmate of ammonia. These ammoniacal salts are soluble in water--as the brown color of the drainings of a manure heap sufficiently indicates. Properly fermented manure, therefore, of good quality, is a much more active and immediately useful fertilizer than fresh, unfermented manure. There need be no loss of ammonia from evaporation, and the manure is far less bulky, and costs far less labor to draw out and spread. The only loss that is likely to occur is from leaching, and this must be specially guarded against. CHAPTER XXI. THE MANAGEMENT OF MANURES.--Continued. WHY DO WE FERMENT MANURE? However much farmers may differ in regard to the advantages or disadvantages of fermenting manure, I have never met with one who contended that it was good, either in theory or practice, to leave manure for months, scattered over a barn-yard, exposed to the spring and autumn rains, and to the summer’s sun and wind. All admit that, if it is necessary to leave manure in the yards, it should be either thrown into a basin, or put into a pile or heap, where it will be compact, and not much exposed. We did not need the experiments of Dr. Vœlcker to convince us that there was great waste in leaving manure exposed to the leaching action of our heavy rains. We did not know exactly how much we lost, but we knew it must be considerable. No one advocates the practice of exposing manure, and it is of no use to discuss the matter. All will admit that it is unwise and wasteful to allow manure to lie scattered and exposed over the barn-yards any longer than is absolutely necessary. We should either draw it directly to the field and use it, or we should make it into a compact heap, where it will not receive more rain than is needed to keep it moist. One reason for piling manure, therefore, is to preserve it from loss, until we wish to use it on the land. “We all admit that,” said the Deacon, “but is there anything actually gained by fermenting it in the heap?”--In one sense, no; but in another, and very important sense, yes. When we cook corn-meal for our little pigs, we add nothing to it. We have no more meal after it is cooked than before. There are no more starch, or oil, or nitrogenous matters in the meal, but we think the pigs can digest the food more readily. And so, in fermenting manure, we add nothing to it; there is no more actual nitrogen, or phosphoric acid, or potash, or any other ingredient after fermentation than there was before, but these ingredients are rendered more soluble, and can be more rapidly taken up by the plants. In this sense, therefore, there is a great gain. One thing is certain, we do not, in many cases, get anything like as much benefit from our manure as the ingredients it contains would lead us to expect. Mr. Lawes, on his clayey soil at Rothamsted, England, has grown over thirty crops of wheat, year after year, on the same land. One plot has received 14 tons of barn-yard manure per acre every year, and yet the produce from this plot is no larger, and, in fact, is frequently much less, than from a few hundred pounds of artificial manure containing far less nitrogen. For nineteen years, 1852 to 1870, some of the plots have received the same manure year after year. The following shows the _average_ yield for the nineteen years: _Wheat _Straw per acre._ per acre._ Plot 5.--Mixed mineral manure, alone 17 bus. 15 cwt. ” 6.--Mixed mineral manure, and 200 lbs. ammoniacal salts 27 bus. 25 cwt. ” 7.--Mixed mineral manure, and 400 lbs. ammoniacal salts 36 bus. 36 cwt. ” 9.--Mixed mineral manure, and 550 lbs. nitrate of soda 37 bus. 41 cwt. ” 2.--14 tons farm-yard dung 36 bus. 34 cwt. The 14 tons (31,360 lbs.) of farm-yard manure contained about 8,540 lbs. organic matter, 868 lbs. mineral matter, and 200 lbs. nitrogen. The 400 lbs. of ammoniacal salts, and the 550 lbs. nitrate of soda, each contained 82 lbs. of nitrogen; and it will be seen that this 82 lbs. of nitrogen produced as great an effect as the 200 lbs. of nitrogen in barn-yard manure. Similar experiments have been made on barley, with even more striking results. The plot dressed with 300 lbs. superphosphate of lime, and 200 lbs. ammoniacal salts per acre, produced as large a crop as 14 tons of farm-yard manure. The average yield of barley for nineteen crops grown on the same land each year was 48 bus. and 28 cwt. of straw per acre on both plots. In other words, 41 lbs. of nitrogen, in ammoniacal salts, produced as great an effect as 200 lbs. of nitrogen in farm-yard manure! During the nineteen years, one plot had received 162,260 lbs. of organic matter, 16,492 lbs. of mineral matter, and 3,800 lbs. of nitrogen; while the other had received only 5,700 lbs. mineral matter, and 779 lbs. of nitrogen--and yet one has produced as large a crop as the other. Why this difference? It will not do to say that more nitrogen was applied in the farm-yard manure than was needed. Mr. Lawes says: “For some years, an amount of ammonia-salts, containing 82 lbs. of nitrogen, was applied to one series of plots (of barley), but this was found to be too much, the crop generally being too heavy and laid. Yet probably about 200 lbs. of nitrogen was annually supplied in the dung, but with it there was no over-luxuriance, and no more crop, than where 41 lbs. of nitrogen was supplied in the form of ammonia or nitric acid.” It would seem that there can be but one explanation of these accurately-ascertained facts. The nitrogenous matter in the manure is not in an available condition. It is in the manure, but the plants can not take it up until it is decomposed and rendered soluble. Dr. Vœlcker analyzed “perfectly fresh horse-dung,” and found that of _free_ ammonia there was not more than one pound in 15 tons! And yet these 15 tons contained nitrogen enough to furnish 140 lbs. of ammonia. “But,” it may be asked, “will not this fresh manure decompose in the soil, and furnish ammonia?” In light, sandy soil, I presume it will do so to a considerable extent. We know that clay mixed with manure retards fermentation, but sand mixed with manure accelerates fermentation. This, at any rate, is the case when sand is added in small quantities to a heap of fermenting manure. But I do not suppose it would have the same effect when a small quantity of manure is mixed with a large amount of sand, as is the case when manure is applied to land, and plowed under. At any rate, practical farmers, with almost entire unanimity, think well-rotted manure is better for sandy land than fresh manure. As to how rapidly, or rather how slowly, manure decomposes in a rather heavy loamy soil, the above experiments of Mr. Lawes afford very conclusive, but at the same time very discouraging evidence. During the 19 years, 3,800 lbs. of nitrogen, and 16,492 lbs. of mineral matter, in the form of farm-yard manure, were applied to an acre of land, and the 19 crops of barley in grain and straw removed only 3,724 lbs. of mineral matter, and 1,064 lbs. of nitrogen. The soil now contains, unless it has drained away, 1,736 lbs. more nitrogen per acre than it did when the experiments commenced. And yet 41 lbs. of nitrogen in an _available condition_ is sufficient to produce a good large crop of barley, and 82 lbs. per acre furnished more than the plants could organize. “Those are very interesting experiments,” said the Doctor, “and show why it is that our farmers can afford to pay a higher price for nitrogen and phosphoric acid in superphosphate, and other artificial manures, than for the same amount of nitrogen and phosphoric acid in stable-manure.” We will not discuss this point at present. What I want to ascertain is, whether we can not find some method of making our farm-yard manure more readily available. Piling it up, and letting it ferment, is one method of doing this, though I think other methods will yet be discovered. Possibly it will be found that spreading well-rotted manure on the surface of the land will be one of the most practical and simplest methods of accomplishing this object. “We pile the manure, therefore,” said Charley, “first, because we do not wish it to lie exposed to the rain in the yards, and, second, because fermenting it in the heap renders it more soluble, and otherwise more available for the crops, when applied to the land.” That is it exactly, and another reason for piling manure is, that the fermentation greatly reduces its bulk, and we have less labor to perform in drawing it out and spreading it. Ellwanger & Barry, who draw several thousand loads of stable-manure every year, and pile it up to ferment, tell me that it takes three loads of fresh manure to make one load of rotted manure. This, of course, has reference to bulk, and not weight. Three tons of fresh barn-yard manure, according to the experiments of Dr. Vœlcker, will make about two tons when well rotted. Even this is a great saving of labor, and the rotted manure can be more easily spread, and mixed more thoroughly with the soil--a point of great importance. “Another reason for fermenting manure,” said the Squire, “is the destruction of weed-seeds.” “That is true,” said I, “and a very important reason; but I try not to think about this method of killing weed-seeds. It is a great deal better to kill the weeds. There can be no doubt that a fermenting manure-heap will kill many of the weed-seeds, but enough will usually escape to re-seed the land.” It is fortunate, however, that the best means to kill weed-seeds in the manure, are also the best for rendering the manure most efficient. I was talking to John Johnston on this subject a few days ago. He told me how he piled manure in his yards. “I commence,” he said, “where the heap is intended to be, and throw the manure on one side, until the bare ground is reached.” “What is the use of that?” I asked. “If you do not do so,” he replied, “there will be some portion of the manure under the heap that will be so compact that it will not ferment, and the weed-seeds will not be killed.” “You think,” said I, “that weed-seeds can be killed in this way?” “I know they can,” he replied, “but the heap must be carefully made, so that it will ferment evenly, and when the pile is turned, the bottom and sides should be thrown into the center of the heap.” LOSS OF AMMONIA BY FERMENTING MANURE. If you throw a quantity of fresh horse-manure into a loose heap, fermentation proceeds with great rapidity. Much heat is produced, and if the manure is under cover, or there is not rain enough to keep the heap moist, the manure will “fire-fang” and a large proportion of the carbonate of ammonia produced by the fermentation will escape into the atmosphere and be lost. As I have said before, we use our horse-manure for bedding the store and fattening pigs. We throw the manure every morning and evening, when the stable is cleaned out, into an empty stall near the door of the stable, and there it remains until wanted to bed the pigs. We find it is necessary to remove it frequently, especially in the summer, as fermentation soon sets in, and the escape of the ammonia is detected by its well known pungent smell. Throw this manure into the pig-cellar and let the pigs trample it down, and there is no longer any escape of ammonia. At any rate, I have never perceived any. Litmus paper will detect ammonia in an atmosphere containing only one seventy-five thousandth part of it; and, as Prof. S. W. Johnson once remarked, “It is certain that a healthy nose is not far inferior in delicacy to litmus paper.” I feel sure that no ammonia escapes from this horse-manure after it is trampled down by the pigs, although it contains an additional quantity of “potential ammonia” from the liquid and solid droppings of these animals. Water has a strong attraction for ammonia. One gallon of ice-cold water will absorb 1,150 gallons of ammonia. If the manure, therefore, is moderately moist, the ammonia is not likely to escape. Furthermore, as Dr. Vœlcker has shown us, during the fermentation of the manure in a heap, ulmic and humic, crenic and apocrenic acids are produced, and these unite with the ammonia and “fix” it--in other words, they change it from a volatile gas into a non-volatile salt. If the heap of manure, therefore, is moist enough and large enough, all the evidence goes to show, that there is little or no loss of ammonia. If the centre of the heap gets so hot and so dry that the ammonia is not retained, there is still no necessity for loss. The sides of the heap are cool and moist, and will retain the carbonate of ammonia, the acids mentioned also coming into play. The ammonia is much more likely to escape from the top of the heap than from the sides. The heat and steam form little chimneys, and when a fermenting manure-heap is covered with snow, these little chimneys are readily seen. If you think the manure is fermenting too rapidly, and that the ammonia is escaping, trample the manure down firmly about the chimneys, thus closing them up, and if need be, or if convenient, throw more manure on top, or throw on a few pailfuls of water. It is a good plan, too, where convenient, to cover the heap with soil. I sometimes do this when piling manure in the field, not from fear of losing ammonia, but in order to retain moisture in the heap. With proper precautions, I think we may safely dismiss the idea of any serious loss of ammonia from fermenting manure. THE WASTE OF MANURE FROM LEACHING. As we have endeavored to show, there is little danger of losing ammonia by keeping and fermenting manure. But this is not the only question to be considered. We have seen that in 10,000 lbs. of fresh farm-yard manure, there is about 64 lbs. of nitrogen. Of this, about 15 lbs. are soluble, and 49 lbs. insoluble. Of mineral matter, we have in this quantity of manure, 559 lbs., of which 154 lbs. are soluble in water, and 405 lbs. insoluble. If we had a heap of five tons of fermenting manure in a stable, the escape of half an ounce of carbonate of ammonia would make a tremendous smell, and we should at once use means to check the escape of this precious substance. But it will be seen that we have in this five tons of fresh manure, nitrogenous matter, capable of forming over 180 lbs. of carbonate of ammonia, over 42 lbs. of which is in a soluble condition. This may be leached day after day, slowly and imperceptibly, with no heat, or smell, to attract attention. How often do we see manure lying under the eaves of an unspouted shed or barn, where one of our heavy showers will saturate it in a few minutes, and yet where it will lie for hours, and days, and weeks, until it would seem that a large proportion of its soluble matter would be washed out of it! The loss is unquestionably very great, and would be greater if it were not for the coarse nature of the material, which allows the water to pass through it rapidly and without coming in direct contact with only the outside portions of the particles of hay, straw, etc., of which the manure is largely composed. If the manure was ground up very fine, as it would be when prepared for analysis, the loss of soluble matter would be still more serious. Or, if the manure was first fermented, so that the particles of matter would be more or less decomposed and broken up fine, the rain would wash out a large amount of soluble matter, and prove much more injurious than if the manure was fresh and unfermented.