The Story of the Soil Part 27

"The director of the Maine State Experiment Station gives us the following:

"'For the first year the largest increase of crop was produced by soluble phosphate. For the second and third years without further addition of fertilizers, better results were obtained from the plots where stable manure and insoluble phosphates had been used.'

"The stable manure and insoluble phosphates here referred to were not applied together, but on separate plots. In deed, the raw phosphate was not used in connection with manure either in Maryland, Rhode Island, Ma.s.sachusetts, Maine, Pennsylvania, or Indiana; and in the extensive experiments in progress in Illinois the raw phosphate has been used, as a rule, not with farm manure, but with green manures; and wherever manure has been used in connection with the raw phosphate, as in Ohio, the comparison is made with the same amounts of manure applied without phosphate.

"The Pennsylvania Report for 1895, page 210, contains the following statement:

"'The yearly average for the twelve years gives us a gain per acre of $2.83 from insoluble ground bone, $2.45 from insoluble South Caroline rock, $1.61 from reverted phosphate, and 48 cents from soluble phosphate, thus giving us considerably better results from the two forms of insoluble phosphate than from the reverted or soluble forms.'

"The Indiana director reports as follows:

"'It will be seen that during the first and second years the rock phosphate produced little effect, while the acid phosphate very materially increased the yields. During the third and fourth seasons, however, the rock produced very striking results, even forging ahead of the acid. This and very similar investigations in progress lead us to believe that rock phosphate is a cheap and effective source of phosphorus where immediate returns are not required.

"In the Ohio experiments eight tons of manure per acre were applied once every three years in a three-year rotation of corn, wheat, and clover, three different fields being used, so that every crop might be grown every year. The average yields for the thirteen years where manure alone was used were:

53.1 bushels of corn 20.6 bushels of wheat 1.63 tons of hay

"The average yields on the unfertilized land were:

32.2 bushels of corn 11.4 bushels of wheat 1.16 tons of hay

"If the corn is worth 35 cents a bushel, the wheat 70 cents, and the hay $6 a ton, in addition to the expense of harvesting and marketing, then the total value of the manure spread on the land is $2.07 a ton.

"Where $1.20 worth of raw phosphate (320 pounds) were added in connection with the manure the average yields were as follows:

61.4 bushels of corn 26.3 bushels of wheat 2.23 tons of hay

"And where $2.40 worth of acid phosphate (320 pounds) were used with the same amount and kind of manure the following average yields were secured:

60.4 bushels of corn 26.5 bushels of wheat 2.16 tons of hay

"These are the actual yield, and by any method of computation yet proposed, each dollar invested in raw phosphate has paid back much more than has a dollar invested in acid phosphate."

"And was the use of the raw phosphate really profitable?" asked Mr.

West.

"Well, you might figure that out for yourself," Percy replied, "preferably using the average prices for your own locality for corn, wheat and clover. As I figure it at prices below the ten-year average for Illinois, the raw phosphate paid about eight hundred per cent. net on the investment."

"Eight hundred per cent! You must mean eight per cent. net.

"No, Sir, I mean eight hundred per cent. net, but you had better take the data and make your own computations. But does it not seem strange that, with such positive knowledge as this available, many of the Illinois landowners who have managed to sell off enough of their original stock of fertility in grain or stock at good prices to enable them to more than pay for their lands, should continue to invest their surplus in more land with hope that it will pay them eight per cent. interest, when they could secure many times that much interest from investing in the permanent improvement of the land they already own?"

"Perhaps it is not so strange," replied Mr. West. "I fear that some of their ancestors did the same thing in Virginia and other Eastern States until the land became poor, and then of course they were 'land poor.' But, say, that 'stone soup' wouldn't be so bad for those Ohio landowners, would it? I should think they would avail themselves of the positive information from their experiment station. Speaking of soup, I wonder if it isn't time for lunch! But tell me; are the Illinois farmers doing anything with raw phosphate?"

"Yes, they are doing something, but by no means as much as they ought. About two months ago a group of the leading farmers from our section of the State went up to Urbana to look over the experiment fields, some of which have been carried on since 1870. The land is the typical corn belt prairie, and consequently the results should be of very wide application. Well, as a result of that day's inspection of the actual field results, an even twelve carloads of raw phosphate were ordered by those farmers upon their return home; and I learned of another community where ten carloads were ordered at once after a similar visit. As an average of the last three years the yield of corn on those old fields has been 23 bushels per acre where corn has been grown every year without fertilizing, 58 bushels where a three-year rotation of corn, oats and clover is followed, and in the same rotation where organic matter, limestone, and phosphorus have been applied the average yield has been 87 bushels in grain farming and 92 bushels in live-stock farming.

"I attended the State Farmers' Inst.i.tute last February, and there I met many men who have had several years' experience with the raw rock. Usually they put on one ton per acre as an initial application and plow it under with a good growth of clover; and, afterward, about one thousand pounds per acre every four years will be ample to gradually increase the absolute total supply of phosphorus in the soil, even though large crops are removed.

"A good many of our thinking farmers are now using one or two cars of raw phosphate every year, and they are figuring hard to keep up the organic matter and nitrogen. The most encouraging thing is the very marked benefit of the phosphate to the clover crop, and of course more clover means more corn in grain farming, and more corn and clover means more manure in live-stock farming.

"On the Illinois fields advantage is taken of these relations in the developing of systems of permanent agriculture. You see, if the phosphate produces more clover, then more clover can be plowed under on that land; or, if the crops are fed, then more manure can be returned to the phosphated land than to the land not treated with phosphate and not producing so large crops. Really the phosphate is not given full credit for what it has accomplished in the Ohio experiments; because, while the land receiving phosphated manure has produced about one-fourth larger crops than the land receiving the untreated manure, the actual amounts of manure applied have been the same, whereas one-fourth more manure can be produced from the phosphated land and if this increased supply of manure were returned to the land it would increase the supply of nitrogen and thus make still larger crop yields possible."

"That is surely the way it would work out in practical farming,"

said Mr. West. "I think I did not tell that $4.80 a ton is the lowest quotation I have been able to get as yet for ground limestone delivered at Blue Mound Station."

"That would make its use prohibitive," said Percy. "You ought to get it for just one-fourth of that, or for $1.20 a ton. In Illinois we can get it delivered a hundred miles from the quarry for $1.20 a ton. It costs no more for a thirty-ton car of ground limestone than the farmer receives for a cow; and the cost of a car of fine-ground natural phosphate is about equal to the price of one horse."

"Of course, our limestone supplies are essentially inexhaustible,"

said Mr. West, "but is that also true of our natural phosphate deposits?"

"It is not true of the high-grade phosphate," replied Percy; "for, according to the information furnished by the United States Geological Survey, it is evident that the known supplies of our high-grade phosphate will be practically exhausted in fifty years if our exportation continues to increase at the prevailing rate. After that is gone we may then draw upon our low-grade phosphate deposits, which though probably not inexhaustible are known to be exceedingly extensive."

CHAPTER x.x.xI

THEORIES VERSUS FACTS

PERCY planned to walk to Blue Mound to take the three-thirty train that Sat.u.r.day afternoon; but Adelaide's parents both insisted that she would willingly drive to the station, and the grandmother discovered that she needed a certain kind of thread which Adelaide could then also get at the store.

"Certainly," said Adelaide, with some merriment, "I always enjoy our departing guests to the train."

"Very well," replied Percy. "If you must go to get the thread and will permit me to be the coachman, I shall be satisfied, for you will be home early."

"Then we will take the colts and buckboard, and I shall be home in less than twenty minutes after your train leaves the station."

"I think I have missed several days of your beautiful 'Indian Summer,' because of my trip to the North," Percy remarked to Mr.

West as they sat on the broad veranda waiting for the hour of two thirty when the colts were to be ready for the drive.

"I wish you might have been with us while Professor Barstow was here," replied Mr. West, "not only because of the mild autumn weather we have had, but also because Professor Barstow has some ideas about questions of soil fertility that are very different from those you hold. He says a young man from Was.h.i.+ngton gave a lecture at his college down in North Carolina, in which he informed them that the cause of infertility of soils is a poisonous substance excreted by the plant itself, and that this can be overcome by changing from one crop to another because the excrete of one plant, while poisonous to that plant, will not be poisonous to other plants of a different kind. Thus, by rotation of crops, good crops could be grown indefinitely on the same land without the addition of plant food. He said that the soil water alone dissolved plenty of plant food from all soils for the production of good crops, and that the supply of plant food will be permanently maintained, because the plant food contained in the subsoil far below where the roots go is being brought to the surface by the rise of the capillary moisture, and that there is in fact a steady tendency toward an acc.u.mulation of plant food in the surface soil. He said that it is never necessary to apply fertilizing material to any soil for the purpose of increasing the supply of plant food in that soil. He admitted that applications of fertilizers sometimes produce increased crop yields, but that the effect was due to the power of the fertilizer to destroy the toxic substances excreted by the plants, and this is really the princ.i.p.al effect of potash, phosphates, and nitrates, and also of farm manure and green manures. Humus, he said, is one of the very best substances for destroying these toxic excrete although they had some other things which were as good or better than any sore of fertilizing materials. He mentioned especially a substance called pyrogallol, which cost $2.00 a pound, and of course it could not be applied on a large scale; but it was as good a fertilizer as anything, although it contains nothing but carbon, oxygen, and hydrogen, which, as you explained to me when you were here before, the plants secure in abundance from air and water. This information had been secured in the laboratories at Was.h.i.+ngton by growing wheat seedlings in water culture for twenty-day periods."

"I have already heard something of those theories," said Percy, "but I shall be glad to have you tell me more about them. As I understand them, we need only to rotate and cultivate and our lands should always continue to produce bountiful crops. Is that correct?"

"I understand that is the theory," replied Mr. West, "but I know it is not correct for my grandfather used to grow two or three times as much wheat per acre as I can grow, and I rotate much more than he did. In fact I can grow only ten to fifteen bushels of wheat per acre once in ten years, whereas he grew from twenty-five to forty bushels per acre in a five-year rotation; and I don't see that there is any particular connection between the growing of wheat seedlings in small pots or bottles for a few twenty-day periods and the growing of crops in soils during successive seasons. No, I don't take any stock in their theories. I think they are _watered, _or perhaps I should say _hydrated, _in deference to science. But I would like to know about this question of plant food coming up from below. That would be a happy solution of the fertilizer problem."

"It is true," said Percy, "that soluble salts are brought to the surface in the rise of moisture by capillarity in times of partial drouth; and in the arid regions where the small amount of water that falls in rain or snow leaves the soil only by evaporation, because there is never enough to produce underdrainage, the salts tend to acc.u.mulate at the surface. The alkali conditions in the arid or semiarid regions of the West are thus produced. But in humid sections where more or less of the rainfall leaves the soil as underdrainage the regular loss by leaching is so much in excess of the rise by capillarity that soils which are not affected by erosion or overflow steadily decrease in fertility even under natural conditions, with no cultivation and no removal of crops. Of course this applies at first only to the mineral plant foods, as phosphorus pota.s.sium, magnesium, and calcium. While mineral supplies are abundant in the surface soil, there may be a large ac.u.mulation of organic matter and nitrogen, especially because of the growth of wild legumes, which are very numerous and in places very abundant, especially on some of the virgin prairies of the West. However, as the process of leaching proceeds there comes a time when the growth of the native vegetation is limited because of a deficiency in some essential mineral plant food, such as phosphorus, or the limestone completely disappears and soil acidity develops which greatly lessens the growth of the legumes.

"Decomposition of organic matter begins almost as soon as any part of the plant ceases to live, and there is certain to come a time when the rate of decomposition and loss exceeds the rate of fixation and acc.u.mulation; and from that time on the organic matter and nitrogen as well as the mineral plant foods continue to decrease in the surface, until finally the natural barrens are developed, such as are found in different sections of the World and in some places even where the rainfall is sufficient for abundant crops."

"Yes, Sir," said Mr. West. "I know that is true. I have visited Tennessee and I know there are some extensive areas there of practically level upland which have always been considered too poor to justify putting under cultivation, and they are called the 'Barrens'."

"I know about those barren lands, too," said Percy. "Our teacher of soil fertility in college told us that a farm is more than a piece of the earth's surface. He said if we only wanted to get a large level tract of upland where the climate is mild and the rainfall abundant and where all sorts of crops do well on good soil, including the wonderful cotton crop which brings a hundred dollars for a thousand pounds, while corn brings forty dollars for a hundred bushels,--well, he said we could go to the Highland Rim of Tennessee where, according to a.n.a.lyses reported in 1897 by the Tennessee Experiment Station, the surface soil of the 'Barrens' contains eighty-seven pounds of phosphorus and the subsoil sixty-one pounds of phosphorus per acre, counting two million pounds of soil in each case. He said, if we didn't like that we might go into the Great Central Basin of Tennessee or the famous Blue Gra.s.s Region of Kentucky and find land that is still extremely productive and more valuable than ever, even after a hundred years of cultivation, and buy land containing from three thousand to fifteen thousand pounds of phosphorus per acre."