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

this plant, hence one of the advantages of underdraining. I have said that shade is favorable to the growth of this fungus, and this fact explains and confirms the common idea that shade is manure. The great object of agriculture is to convert the nitrogen of our soils, or of green crops plowed under, or of manure, into nitric acid, and then to convert this nitric acid into profitable products with as little loss as possible. Nitrogen, or rather nitric acid, is the most costly ingredient in plant food, and unfortunately it is very easily washed out of the soil and lost. Perhaps it is absolutely impossible to entirely prevent all loss from leaching; but it is certainly well worth our while to understand the subject, and to know exactly what we are doing. In a new country, where land is cheap, it may be more profitable to raise as large crops as possible without any regard to the loss of nitric acid. But this condition of things does not last long, and it very soon becomes desirable to adopt less wasteful processes. In Lawes and Gilbert’s experiments, there is a great loss of nitric acid from drainage. In no case has as much nitrogen been obtained in the increased crop as was applied in the manure. There is always a loss and probably always will be. But we should do all we can to make this loss as small as possible, consistent with the production of profitable crops. There are many ways of lessening this loss of nitric acid. Our farmers sow superphosphate with their wheat in the autumn, and this stimulates, we think, the growth of roots, which ramify in all directions through the soil. This increased growth of root brings the plant in contact with a larger feeding surface, and enables it to take up more nitric acid from its solution in the soil. Such is also the case during the winter and early spring, when a good deal of water permeates through the soil. The application of superphosphate, unquestionably in many cases, prevents much loss of nitric acid. It does this by giving us a much greater growth of wheat. I was at Rothamsted in 1879, and witnessed the injurious effect of an excessive rainfall, in washing out of the soil nitrate of soda and salts of ammonia, which were sown with the wheat in the autumn. It was an exceedingly wet season, and the loss of nitrates on all the different plots was very great. But where the nitrates or salts of ammonia were sown in the spring, while the crops were growing, the loss was not nearly so great as when sown in the autumn. The sight of that wheat field impressed me, as nothing else could, with the importance of guarding against the loss of available nitrogen from leaching, and it has changed my practice in two or three important respects. I realize, as never before, the importance of applying manure to crops, rather than to the land. I mean by this, that the object of applying manure is, not simply to make land rich, but to make crops grow. Manure is a costly and valuable article, and we want to convert it into plants, with as little delay as possible, which will, directly or indirectly, bring in some money. Our climate is very different from that of England. As a rule, we seldom have enough rain, from the time corn is planted until it is harvested, to more than saturate the ground on our upland soils. This year is an exception. On Sunday night, May 20, 1883, we had a northeast storm which continued three days. During these three days, from three to five inches of rain fell, and for the first time in many years, at this season, my underdrains discharged water to their full capacity. Had nitrate of soda been sown on bare land previous to this rain, much of it would, doubtless, have been lost by leaching. This, however, is an exceptional case. My underdrains usually do not commence to discharge water before the first of December, or continue later than the first of May. To guard against loss of nitrogen by leaching, therefore, we should aim to keep rich land occupied by some crop, during the winter and early spring, and the earlier the crop is sown in the autumn or late summer, the better, so that the roots will the more completely fill the ground and take up all the available nitrogen within their reach. I have said that this idea had modified my own practice. I grow a considerable quantity of garden vegetables, principally for seed. It is necessary to make the land very rich. The plan I have adopted to guard against the loss of nitrogen is this: As soon as the land is cleared of any crop, after it is too late to sow turnips, I sow it with rye at the rate of one and a half to two bushels per acre. On this rich land, especially on the moist low land, the rye makes a great growth during our warm autumn weather. The rye checks the growth of weeds, and furnishes a considerable amount of succulent food for sheep, during the autumn or in the spring. If not needed for food, it can be turned under in the spring for manure. It unquestionably prevents the loss of considerable nitric acid from leaching during the winter and early spring. Buckwheat, or millet, is sometimes sown on such land for plowing under as manure, but as these crops are killed out by the winter, they cannot prevent the loss of nitric acid during the winter and spring months. It is only on unusually rich land that such precautions are particularly necessary. It has been thought that these experiments of Lawes and Gilbert afford a strong argument against the use of summer-fallows. I do not think so. A summer-fallow, in this country, is usually a piece of land which has been seeded down one, two, and sometimes three years, with red clover. The land is plowed in May or June, and occasionally in July, and is afterwards sown to winter wheat in September. The treatment of the summer-fallow varies in different localities and on different farms. Sometimes the land is only plowed once. The clover, or sod, is plowed under deep and well, and the after-treatment consists in keeping the surface soil free from weeds, by the frequent use of the harrow, roller, cultivator or gang-plow. In other cases, especially on heavy clay land, the first plowing is done early in the spring, and when the sod is sufficiently rotted, the land is cross-plowed, and afterwards made fine and mellow by the use of the roller, harrow, and cultivator. Just before sowing the wheat, many good, old-fashioned farmers, plow the land again. But in this section, a summer-fallow, plowed two or three times during the summer, is becoming more and more rare every year. Those farmers who summer-fallow at all, as a rule, plow their land but once, and content themselves with mere surface cultivation afterwards. It is undoubtedly true, also, that summer fallows of all kinds are by no means as common as formerly. This fact may be considered an argument against the use of summer-fallowing; but it is not conclusive in my mind. Patient waiting is not a characteristic of the age. We are inclined to take risks. We prefer to sow our land to oats, or barley, and run the chance of getting a good wheat crop after it, rather than to spend several months in cleaning and mellowing the land, simply to grow one crop of wheat. It has always seemed to me entirely unnecessary to urge farmers not to summer-fallow. We all naturally prefer to see the land occupied by a good paying crop, rather than to spend time, money, and labor, in preparing it to produce a crop twelve or fifteen months afterwards. Yet some of the agricultural editors and many of the agricultural writers, seem to take delight in deriding the old-fashioned summer-fallow. The fact that Lawes and Gilbert in England find that, when land contains considerable nitric acid, the water which percolates through the soil to the underdrains beneath, contains more nitrate of lime when the land is not occupied by a crop, than when the roots of growing plants fill the soil, is deemed positive proof that summer-fallowing is a wasteful practice. If we summer-fallowed for a spring crop, as I have sometimes done, it is quite probable that there would be a loss of nitrogen. But, as I have said before, it is very seldom that any water passes through the soil from the time we commence the summer-fallow until the wheat is sown in the autumn, or for many weeks afterwards. The nitrogen, which is converted into nitric acid by the agency of a good summer-fallow, is no more liable to be washed out of the soil after the field is sown to wheat in the autumn, than if we applied the nitrogen in the form of some readily available manure. I still believe in summer fallows. If I had my life to live over again, I would certainly summer-fallow more than I have done. I have been an agricultural writer for one-third of a century, and have persistently advocated the more extended use of the summer-fallow. I have nothing to take back, unless it is what I have said in reference to “fall-fallowing.” Possibly this practice may result in loss, though I do not think so. A good summer-fallow, on rather heavy clay land, if the conditions are otherwise favorable, is pretty sure to give us a good crop of wheat, and a good crop of clover and grass afterwards. Of course, a farmer who has nice, clean sandy soil, will not think of summer-fallowing it. Such soils are easily worked, and it is not a difficult matter to keep them clean without summer-fallowing. Such soils, however, seldom contain a large store of unavailable plant food, and instead of summer-fallowing, we had better manure. On such soils artificial manures are often very profitable, though barn-yard manure, or the droppings of animals feeding on the land, should be the prime basis of all attempts to maintain, or increase, the productiveness of such soils. Since this book was first published, I do not know of any new facts in regard to the important question of, how best to manage and apply our barn-yard manure, so as to make it more immediately active and available. It is unquestionably true, that the same amount of nitrogen in barn-yard manure, will not produce so great an effect as its theoretical value would indicate. There can be no doubt, however, that the better we feed our animals, and the more carefully we save the liquids, the more valuable and active will be the manure. The conversion of the inert nitrogen of manures and soils, into nitric acid, as already stated, is now known to be produced by a minute fungus. I hope it will be found that we can introduce this _bacterium_ into our manure piles, in such a way as to greatly aid the conversion of inert nitrogen into nitrates. Experiments have been made, and are still continued, at Woburn, under the auspices of the Royal Agricultural Society of England, to ascertain, among other things, whether manure from sheep receiving an allowance of cotton-seed cake is any richer than that from sheep, otherwise fed alike, but having, instead of cotton-seed cake, the same amount of corn meal. We know that such manure contains more nitrogen, and other plant food, than that from the corn meal. But the experiments so far, though they have been continued for several years, do not show any striking superiority of the manure from cotton-seed cake over that from corn meal. I saw the wheat on these differently manured plots in 1879. Dr. Vœlcker and Dr. Gilbert, told me that, one of two plots was dressed with the cotton-seed manure, and the other with the corn meal manure, and they wanted me to say which was the most promising crop. I believe the one I said was the better, was the cotton-seed plot. But the difference was very slight. The truth is that such experiments must be continued for many years before they will prove anything. As I said before, we know that the manure from the cotton-seed cake is richer in nitrogen than that from the corn meal; but we also know that this nitrogen will not produce so great an effect, as a much smaller amount of nitrogen in salts of ammonia, or nitrate of soda. In going over these experiments, I was struck with the healthy and vigorous appearance of one of the plots of wheat, and asked how it was manured. Dr. Vœlcker called out, “clover, Mr. Harris, clover.” In England, as in America, it requires very little observation and experience to convince any one of the value of clover. After what I have said, and what the Deacon, the Doctor, Charley and the Squire have said, in the pages of this book, I hope no one will think that I do not appreciate the great value of red clover as a means of enriching our land. Dr. Vœlcker evidently thought I was skeptical on this point. I am not. I have great faith in the benefits to be derived from the growth of clover. But I do not think it originates fertility; it does not get nitrogen from the atmosphere. Or at any rate, we have no evidence of it. The facts are all the other way. We have discussed this question at considerable length in the pages of this book, and it is not necessary to say more on the subject. I would, however, particularly urge farmers, especially those who are using phosphates freely, to grow as much clover as possible, and feed it out on the farm, or plow it under for manure. The question is frequently asked, whether the use of phosphates will ultimately impoverish our farms. It may, or it may not. It depends on our general management. Theoretically, the use of a manure furnishing only one element of plant food, if it increases the growth of crops which are sold from the farm, must have a tendency to impoverish the land of the other elements of plant food. In other words, the use of superphosphate furnishing only, or principally, phosphoric acid, lime and sulphuric acid, must have a tendency to impoverish the soil of nitrogen and potash. Practically, however, it need do nothing of the kind. If the land is well cultivated, and if our low, rich, alluvial portions of the farm are drained, and if the hay, grass, clover, straw and fodder crops are retained, the more phosphates we use, the richer and more productive will the farm become. And I think it is a fact, that the farmers who use the most phosphates, are the very men who take the greatest pains to drain their land, cultivate it thoroughly, and make the most manure. It follows, therefore, that the use of phosphates is a national benefit. Some of our railroad managers take this view of the subject. They carry superphosphate at a low rate, knowing that its use will increase the freight the other way. In other words, they bring a ton of superphosphate from the seaboard, knowing that its use will give them many tons of freight of produce, from the interior to the seaboard. It is not an uncommon thing for two hundred pounds of superphosphate, to give an increase of five tons of turnips per acre. Or, so to speak, the railroad that brings one ton of superphosphate from the seaboard, might, as the result of its use, have fifty tons of freight to carry back again. This is perhaps an exceptionably favorable instance, but it illustrates the principle. Years ago, before the abolition of tolls on the English turnpike roads, carriages loaded with lime, and all other substances intended for manure, were allowed to go free. And our railroads will find it to their interest to transport manures of all kinds, at a merely nominal rate. Many people will be surprised at the recommendation of Sir John B. Lawes, not to waste time and money in cleaning poor land, before seeding it down to grass. He thinks that if the land is made rich, the superior grasses overgrow the bad grasses and weeds. I have no doubt he is right in this, though the principle may be pushed to an extreme. Our climate, in this country, is so favorable for killing weeds, that the plow and the cultivator will probably be a more economical means of making our land clean, than the liberal use of expensive manures. It depends, doubtless, on the land and on circumstances. It is well to know that manure on grass land, will so increase the growth of the good grasses, as to smother the weeds. Near my house was a piece of land that I wanted to make into a lawn. I sowed it with grass seed, but the weeds smothered it out. I plowed it, and hoed it, and re-seeded it, but still the weeds grew. Mallows came up by the thousand, with other weeds too numerous to mention. It was an eye-sore. We mowed the weeds, but almost despaired of ever making a decent bit of grass land out of it. It so happened that, one year, we placed the chicken coops on this miserable weedy spot. The hens and chickens were kept there for several weeks. The feed and the droppings made it look more unsightly than ever, but the next spring, as if by magic, the weeds were gone and the land was covered with dark green luxuriant grass. In regard to the use of potash as a manure, we have still much to learn. It would seem that our grain crops will use soda, if they cannot get potash. They much prefer the potash, and will grow much more luxuriantly where, in the soil or manure, in addition to the other elements of plant food, potash is abundant. But the increased growth caused by the potash, is principally, if not entirely, straw, or leaves and stem. Nature makes a great effort to propagate the species. A plant of wheat or barley, will produce seed if this is possible, even at the expense of the other parts of the plant. For grain crops, grown for seed, therefore, it would seem to be entirely unprofitable to use potash as a manure. If the soil contains the other elements of plant food, the addition of potash may give us a much more luxuriant growth of leaves and stem, but no more grain or seed. For hay, or grass or fodder crops, the case is very different, and potash may often be used on these crops to great advantage. I am inclined to think that considerable nitrate of soda will yet be used in this country for manure. I do not suppose it will pay as a rule, on wheat, corn and other standard grain crops. But the gardener, seed grower, and nurseryman, will find out how to use it with great profit. Our nurserymen say that they cannot use artificial manures with any advantage. It is undoubtedly true that a dressing of superphosphate, sown on a block of nursery trees, will do little good. It never reaches the roots of the plants. Superphosphate can not be washed down deep into the soil. Nitrate of soda is readily carried down, as deep as the water sinks. For trees, therefore, it would seem desirable to apply the superphosphate before they are planted, and plow it under. And the same is true of potash; but nitrate of soda would be better applied as a top-dressing every year, early in the spring. The most discouraging fact, in Lawes’ and Gilbert’s experiments, is the great loss of nitrogen. It would seem that, on an average, during the last forty years, about one-half the nitrogen is washed out of the soil, or otherwise lost. I can not but hope and believe that, at any rate in this country, there is no such loss in practical agriculture. In Lawes’ and Gilbert’s experiments on wheat, this grain is grown year after year, on the same land. Forty annual crops have been removed. No clover is sown with the wheat, and great pains are taken to keep the land clean. The crop is hoed while growing, and the weeds are pulled out by hand. The best wheat season during the forty years, was the year 1863. The poorest, that of 1879; and it so happened, that after an absence of thirty years, I was at Rothamsted during this poor year of 1879. The first thing that struck me, in looking at the experimental wheat, was the ragged appearance of the crop. My own wheat crop was being cut the day I left home, July 15. Several men and boys were pulling weeds out of the experimental wheat, two weeks later. Had the weeds been suffered to grow, Sir John Bennet Lawes tells us, there would be less loss of nitrogen. The loss of nitrogen in 1863, was about twenty-four pounds per acre, and in 1879 fifty pounds per acre--the amount of available