by G.F. Warren
This material appeared in the very first edition of the Small Farmer’s Journal. As those old issues are hard to come by, we have had several requests for article reprints. We deemed it worthy to revisit this important subject by starting out with the best basic information we could find. This stuff was originally published in 1909.
I have been personally keen to go back to the basics of livestock manure as fertilizer given the nepharious campaign launched a few years back from within the USDA. They use a general brush on a portrait of manure as dangerous and unsuitable for fertilizer use. And they support their arguments with unsubstantiated and conveniently curved logic. (The USDA continues in a lame advance trying to hasten the loss of small independent farmers. They will use any argument to that end.)
We Millers use the manure from our work horses to raise most excellent vegetables and I continue as a moderately healthy old man in spite of (or because of) that. I would argue that long before there be any discussion about criminalizing we should have that discussion about most chemical fertilizers, herbicides, and insecticides. As for guaranteeing safety of manures topically applied I might suggest that desk jockeys aren’t qualified to make determinations. Actual working farmers, in order to realize some success, must be intelligent. A basic understanding of the cleanliness issues at hand will result, as it has for centuries, on excellent and healthy results. LRM
IMPORTANCE OF MANURE
Over half a century ago a French scientist declared that one of the most important lessons for the farmer to learn was how to produce good barnyard manure and to use it rationally; that the fundamental question was and would remain the manure question. The older our farm lands become, the more truth we see in his statement. In many parts of America the manure is thrown away. In regions where thousands of dollars are spent for fertilizers, a half of the value of manure is usually lost before it is applied to the land.
Figured at the price that the plant-food in manure would cost in fertilizers, the amount produced in the United States is worth $2,353,000,000 per year. The value of the corn crop in 1908 was about two-thirds this amount, $1,601,000,000.
VALUE OF MANURE
The value of manure is often figured on the basis of what the nitrogen, phosphoric acid and potash would cost if purchased in commercial fertilizers. The plant-food in manure is less soluble than that in fertilizers; on the other hand, fertilizers do not give any value to the humus, which is a very important part of the manure. Field trials usually show that this is a fair method of comparison with fertilizers, particularly when the lasting effects are considered. Truck-growers in New Jersey, who buy both manure and fertilizers, pay much more for the plant-food in manure than they have to pay for it in the fertilizers. They feel that they must have the manure, even if it is more expensive. Sometimes they dispense with manure when they can plow under clover.
The price at which manure can be purchased is quite variable. In parts of the West a man is paid to haul it away to get rid of it. Farmers in New Jersey purchase it by the carload from Philadelphia and New York at about $2.50 per ton, and there is still the expense of hauling to the farms. In many of the smaller cities of the East, it can be had for the hauling, in others, it must be paid for.
How much manure is worth on a given farm depends on how much it is needed. It may be worth more or less than the fertility in it would cost in fertilizers.
Seventy-nine analyses of manure and bedding at the Massachusetts Experiment Station gave an average of 66 percent water, 0.45 percent nitrogen, 0.33 percent phosphoric acid, 0.56 percent potash. This is practically one-half percent of nitrogen and potash, and one-third percent phosphoric acid. The plant-food in a ton of such manure would cost about $2.83 (4×1/2+1/3+1/2).
At the Cornell Experiment Station, each ton of manure gave $2.58 worth of hay and oats in three years above the value from the untreated land. In one three-year rotation of wheat, clover, potatoes in Ohio, each ton of manure gave $2.96 worth of increased crops. In each case, there will be a considerable benefit from the manure on later crop, as the good effects of manure are not all gone in three years.
Experiments at Rothamsted, England, during fifty years on land unmanured, manured continuously, and manured during the first twenty years only, showed a gradual decrease in the crop on the unmanured soil and a gradual increase from year to year on the manured soil. When the application was stopped there was a gradual decrease, but, at the end of thirty years after the last application, the yield was still double that on the unmanured part. (See Fig. 1.)
FACTORS INFLUENCING THE VALUE OF MANURE
Young animals, poor animals, those producing a rich product, as milk, or those doing hard work, usually digest their food more fully, so that the manure is less valuable. If the food is rich, the manure is improved. The manure of different animals differs in value. That from poultry is most valuable. Sheep manure is more valuable than cow manure, chiefly because it is drier. The character of bedding also influences the value of manure. Sawdust and shavings are of no value, so that if they are used the manure is not so valuable as when straw is used. If the liquid portion is lost, if it ferments, or if it leaches, the manure will be less valuable.
FERTILIZING VALUE OF FOOD AND OF MANURE
From 65 to 75 percent of the nitrogen, phosphoric acid and potash fed to cows is recovered in the manure, with fattening animals 85 to 95 percent is recovered. In general, it is safe to assume that three-fourths of the fertility in the feed is recovered in the manure. This, of course, assumes that the liquid portion is saved and that leaching and other losses are prevented.
This fact has an important bearing on farm management. Cottonseed meal, dried blood and tankage are used as fertilizers and as feed. The meal is fed to cattle. The dried blood and tankage are fed to hogs and poultry. It is usually more profitable to feed these to animals and use the manure on the land rather than purchase fertilizers. In general, it is more profitable to purchase fertility as feed for stock than to buy it in a fertilizer bag. A good many eastern farmers feed sheep and beef cattle not so much for the profit that the animals give directly as for the manure that they produce. Even in new countries it is well to consider the question of feeding grain to animals rather than selling it. If the stock can be made to pay nearly as well as grain selling, it is to be preferred on account of the greater crops that can be secured in the future.
AMOUNT AND VALUE OF MANURE PRODUCED BY FARM ANIMALS
A 1200-pound horse will produce about eleven tons of excrement per year, which, together with the bedding, will make about fourteen tons of manure. A cow produces about the same amount. Steers fed at the Ohio Station averaged at the rate of nine tons per year. An equal weight of sheep produces fewer tons, but the manure is drier, so that about the same amount of plant-food is produced. A fairly safe rule for any stock except sheep, poultry and hogs is to count one ton per month for each 1,000 pounds of animals kept. To purchase an equal amount of plant-food in fertilizers would cost about $40 per year. The following table gives results procured by Roberts:
The amount of manure produced must be considered in planning a cropping system for a farm. If one wishes to manure one-fifth of the land every year with 10 tons per acre, there would have to be provided two tons per year for each acre of the farm. This would require about one cow or horse, or equivalent, for each six acres of land. Enough more stock would have to be kept to make up for time on the pasture, provided the pasture were not a part of the crop-rotation.
LOSSES OF MANURE
The great sources of loss of manure are the loss of the liquid portion, the leaching out of the fertility by rains, and fermentation.
The liquid portion of manure is much more valuable per ton than is the solid portion, as it contains over twice as much nitrogen and most of the potash. The relative composition of the solid and the liquid portions is as follows:
With cows, over one-fourth of the total excrement is liquid. This is worth about as much as the solid manure. Yet many farmers have arranged their barns so as to drain off the liquid portion. In this way it is easy to lose fertilizing material that would cost $10 to $15 per year for each cow kept. Straw, or some other absorbing material, should be used so freely that none of the liquid is lost. It is also desirable to have cement gutters in cow barns.
If the manure is exposed to heavy rains, the results are still more serious, as the drainage from a manure heap is even more valuable than the liquid manure:
Roberts exposed 4,000 pounds of manure from April 25 to September 22. At the end of this time there were only 1,730 pounds:
Not only was there a loss of 63 percent of the value of the plant-food, but the loss in weight was due mostly to loss of organic matter, which should have been saved to make humus. At the New Jersey Station, manure exposed for four months lost over half of its value.
Farmers usually fail to appreciate this loss, because a ton of well-rotted manure is worth more than a ton of fresh manure. The trouble is that after exposure there are so few tons. One farmer who looked over these figures remarked that he hauled 200 loads of manure to a pile beside a field in the spring, and that when he came to spread it in the fall, he had 60 loads.
At the Ohio Station, manure exposed three months in an open barnyard lost one-third of its fertilizing value. This manure was used on crops and was found to be 27 percent less effective than the same amount of manure that had not been thus exposed (Fig. 2). As manure is exposed under the eaves in barnyards, it certainly loses much more than half of its value. But merely being under cover is not a sure preventive of loss. Unless it is kept moist and compact, it will ferment, and a large part of the nitrogen will pass off into the air.
The ideal way to care for manure is to spread it on the land as fast as it is made. One can keep a wagon or manure-spreader on which the manure is thrown each day. When a load is ready, it is hauled to the field and spread at once. This is not so difficult as at first appears. It saves the labor of handling the manure twice – once to throw it out of the barn, and once to put it on the wagon. When the tilled land is all in crops, it can be spread on the pastures or meadows, so that there is nearly always a place to put it.
If manure cannot be hauled in this manner, the next best way is to have a covered barnyard or shed where all the manure is put and in which stock is kept. The stock will pack the manure and keep it moist – conditions that are essential for preserving it. If it is kept tramped and moist, and if the shed has a cement floor, there will be practically no loss. A cement floor under steers in Ohio was half paid for in one year by the saving of manure.
When manure is kept in this way, it should be hauled out during the winter and spring. During the summer, when the stock are at pasture, it will dry out and ferment, and much of the nitrogen will escape to the air. If it could be kept moist, this loss could be avoided.
To prevent losses from manure, it is necessary:
- To use absorbents to retain all the liquid part.
- To spread it on the land as soon as possible.
- If it cannot be spread at once, keep it under cover, tramped and moist, and on a cement floor, if possible.
Various materials are used with manure to help to retain the nitrogen and to reinforce the manure at the same time. Kainit, gypsum, acid phosphate and floats are most commonly used. Of these, acid phosphate and floats are best, unless the farm is in particular need of potash. Any of these substances tend to retain the nitrogen that might escape to the air as a result of fermentation. They do not prevent much of the losses due to leaching. About 40 pounds of acid phosphate, or twice this amount of floats, may be mixed with each ton of manure as it accumulates. At the Ohio Station 40 pounds of acid phosphate, worth about 30 cents, was used with each ton of manure. This produced a ten-year average increase in crops to the value of $4.57 for each ton of manure above the cost of the acid phosphate. It practically doubled the benefits from each ton of manure. This is doubtless due in part to the saving of nitrogen, and in part to the need of phosphoric acid on this land.
APPLICATION OF MANURE
A good place to apply manure is preceding the corn crop. It is also desirable as a top-dressing for grass land. Unless there is some reason for not doing so, the manure should be applied on the most valuable crop that is being raised – corn, cotton, potatoes, truck, etc. On fairly fertile land it is not best to apply it directly to the small grain crops, as oats, wheat, barley, as they are likely to make too rank a growth.
On the new lands of the West, manure sometimes injures crops when it is plowed under, chiefly because it causes the land to dry out. On such lands the use of manure should not be condemned. It should be applied as thinly as possible as a top-dressing on grass lands, where it will help to retain the moisture. When it is plowed under, it will then be so well rotted as to do no harm. Sometimes it is best to let it become well rotten before applying on such land.
Small applications frequently made are much better than heavy applications less frequently. The application should, if possible, be thin enough so that the entire farm may be covered in three to five years.
Manure may be applied at any time. The sooner it is on the land the better. It is better to apply it in the fall or winter than to store it until spring. It is much better to apply it in the spring than to wait till fall. It is sometimes feared that applications when the ground is frozen or when there is snow on the land may result in loss, but experiments have not shown this to be serious. The smaller amount of farm work during the winter also makes this a desirable time to spread manure.
The best method of applying manure, when large amounts are to be hauled, is to use a manure-spreader (Fig. 7). These are too expensive to use on very small farms. The chief advantages of a manure-spreader are that it saves labor and will distribute the same amount of manure over more land and spread it more evenly. If a spreader is not used, the manure should be spread from a wagon, and it may be desirable to go over it with a brush- harrow or spike-tooth harrow to secure an even distribution. It should certainly not be thrown into small piles in the field and then spread, as this involves handling it once more than is necessary.
In conclusion, it may be said that the chief means of maintaining the fertility of the land are the rotation of crops including grass and leguminous crops in the rotation, and the use of stable manure – which involves the keeping of stock.
Crops are sometimes grown for the purpose of plowing under as green-manure. Rye, buckwheat, cow-peas, crimson clover, are frequently grown for this purpose. This is a desirable practice when the land is very deficient in humus. So far as possible, such crops should be grown without extra labor. Crimson clover or cow-peas may be sown in corn or cotton at the last cultivation with little expense except for seed. In regions too far north for these plants rye is often used. It should be plowed under in the spring before it has made enough growth to exhaust the water of the soil.
It is not often wise to make a regular practice of plowing under crops that are worth harvesting. It will be better to feed them to stock and use the manure. If one is trying to get worn-out land to produce, or under certain conditions where stock cannot profitably be kept, the practice may be followed regularly, and by many means catch crops too small to harvest, but worth plowing under, may be procured.
One is likely to be deceived as to the amount of material that is being added to the soil by the practice. Green crops are about 70 to 75 percent water, which is likely to deceive one as to the amount of organic matter.
Some of the best potato growers plow under a clover crop every three years for keeping up the humus supply. The potatoes are grown on the sod and are heavily fertilized.
Soil is the source of food that sustains mankind. It is productive so long as it contains sufficient quantities of all the essential plant-food elements, and so long as the right methods are observed by the farmer in working his land.
The supply of plant-food elements in the soil is not inexhaustible. Like a bank account, it becomes depleted if the amount withdrawn is greater than the amount deposited.
With the removal of each crop, the soil surrenders some of its fertility. If an equal amount of fertility is returned by man, productiveness is maintained.
Experience has proved to farmers in every section of the country that barnyard manure is of great value as a soil fertilizer and a factor in permanent agriculture. The insistent urgings of scientists and farm experts have moved farmers to try a regular plan of covering their fields with the manure and waste vegetable matter from their barns and feed yards. The results have proved gratifying, and, as a general rule, farmers value highly the manure that was once considered a useless by-product of farming that was to be disposed of in the easiest possible manner or permitted to rot and waste away in piles about the barnyard.
One of the major reasons for the wastage of manure in the early days of agricultural expansion was the great amount of hand labor required to get it distributed evenly over the fields. The hard work of pitching into high wagon boxes, unloading into piles, and spreading by hand or spreading direct from the load was distasteful even to the farmer who was most conscientious about maintaining the fertility of his fields. The result was a more or less general laxity in conserving the manure that is now valued so highly.
The following graphs, furnished through courtesy of the Ohio State University, supply interesting facts about the value of manure in maintaining soil fertility, and, in addition, show results obtained from various methods of handling manure.
The introduction of the manure spreader not only gave the farmer an easier and quicker method of spreading his barnyard manure, but it also paved the way for a more concentrated effort on the part of agricultural leaders to impress upon him the value of its use in increasing crop production. Winning the farmer to the use of the spreader was comparatively easy when both the labor-saving and crop-producing features were pointed out to him.
Today, the great majority of farms are equipped with some type of manure spreader. Farmers are adding to their profits and building up their soils by utilizing the manure that was once wasted. The general practice is to spread the manure on the fields as it accumulates, thus getting the full benefit of all the plant-food elements.
To be most effective, manure must be spread evenly over the entire surface of the field. If it is deposited in bunches, part of the soil is without fertilizer and part is over-supplied. If the manure has a large amount of straw in it, difficulty is experienced in plowing and cultivating spots where it is bunched. The proper loading and operating of the manure spreader will overcome or lessen the possibilities of uneven spreading, provided the spreader is constructed properly.
TYPES OF SPREADERS
There are two general types of manure spreaders—horse-drawn, in which the traction of the rear wheels furnishes power for driving the beaters, and tractor-driven, in which the tractor engine, through the power take-off, operates the beaters.
A style of horse-drawn spreader in common use is shown in Fig. 10. It has three beaters. The upper and main beaters shred the manure; the spiral beater deposits it evenly over the entire width, making a well-defined line beyond the drive wheels.
The manure is carried back to the beaters by a steel slat conveyor, the speed of which is controlled by the feed lever from the driver’s seat. From five to twenty loads can be spread per acre, according to the setting of the feed lever.
The operator must be sure to keep the feed lever forward, in neutral, whenever the machine is not in gear or whenever the beaters are not operating. If the feed lever is left in operating position when starting to the field with a load, the conveyor forces the load back against the beater, resulting in breakage in some part of the feed mechanism. The feed lever should be thrown into neutral, also, when turning sharply while spreading.
With the control lever, the operator shifts the main drive chain so that it is in contact with the large drive sprocket. The three beaters are driven by two chains, both of which are set into action by the drive sprocket. The beaters should not be put into gear in this manner while the machine is in motion. The control lever should be moved to the rear only when the spreader is standing still.
In care and operation, the tractor-driven spreader (Fig. 9) is so similar to the horse-drawn type that the instructions given for the horse-drawn apply to the power-driven spreader as well.
BUILDING THE LOAD
It is much easier on both the team and the spreader if the operator starts to load from the front end, finishing at the beater end. The shredding process, which is the work of the beaters, is less of a strain when the load is built in this manner, resulting in lighter draft and less wear on the machine.