We have based our decision regarding the use of ground limestone very largely upon the long-continued work of the Pennsylvania Agricultural Experiment Station as to the comparative effects of ground limestone and burned lime, which is supported, to be sure, by all comparative tests so far as our Illinois soil investigators have been able to learn.
The practicability and economy of using the fineground natural phosphate has been even more conclusively established, as you already know, by the concordant results of half a dozen state experiment stations. There are only two objections to the use of the raw phosphate. One of these is the short-sighted plan or policy of the average farmer, and the other is the combined influence of about four-hundred fertilizer manufacturers who prefer to sell, quite naturally, perhaps, two tons of acid phosphate for $30, or four tons of so-called "complete" fertilizer for $70 to $90, rather than to see the farmer buy direct from the phosphate mine one ton of fine-ground raw rock phosphate in which he receives the same amount of phosphorus, at a cost of $7 to $9.
Until we can provide a greater abundance of decaying organic matter we may make some temporary use of kainit, in case the experiments conducted by the state show that it is profitable to do so.
In a laboratory experiment, made at college it was shown that when raw phosphate was shaken with water and then filtered, the filtrate contained practically no dissolved phosphorus; but, if a dilute solution of such salts as exist in kainit was used in place of pure water, then the filtrate would contain very appreciable amounts of phosphorus.
In addition to this benefit, the kainit will furnish some readily available potassium, magnesium, and sulfur; and, by purchasing kainit in carload lots, the potassium will cost us less than it would in the form of the more expensive potassium chlorid or potassium sulfate purchased in ton lots. Of course we do not need this in order to add to our total stock of potassium, but more especially I think to assist in liberating phosphorus from the raw phosphate which is naturally contained in the soil and which we shall also apply to the soil, unless the Government permits the fertilizer trusts to get such complete control of our great natural phosphate deposits that they make it impossible for farmers to secure the fine-ground rock at a reasonable cost, which ought not, I would say, to be more than one hundred per cent. net profit above the expense of mining, grinding, and transportation. We may feel safe upon the matter of transportation rates, for the railroads are operated by men of large enough vision to see that the positive and permanent maintenance of the fertility of the soil is the key to their own continued prosperity, and some of them are already beginning to understand that the supply of phosphorus is the master key to the whole industrial structure of America; for, with a failing supply of phosphorus, neither agriculture nor any dependent industry can permanently prosper in this great country.
If we retain the straw on the farm and sell only the grain, the supply of potassium in the surface soil of Poorland Farm is sufficient to meet the needs of a fifty bushel crop of wheat per acre every year for nineteen hundred and twenty years, or longer than the time that has passed since the Master walked among men on the earth; whereas, the total phosphorus content of the same soil is sufficient for only seventy such crops, or for as long as the full life of one man. Keep in mind that Poorland Farm is near Heart-of-Egypt, and that this is the common soil of our "Egyptian Empire," which contains more cultivable land than all New England, has the climate of Virginia, and a network of railroads scarcely equalled in any other section of this country, and in addition it is more than half surrounded by great navigable rivers.
On Poorland Farm there are seven forty-acre fields which are at least as nearly level as they ought to be to permit good surface drainage, and there is no need that a single hill of corn should be omitted on any one of these seven fields; and I am confident that with an adequate supply of raw phosphate rock and magnesian limestone and a liberal use of legume crops this land can be made to pay interest on $300 an acre.
Why not? At Rothamsted, England, they have averaged thirty-eight and four-tenths bushels of wheat per acre during the last twenty years in an experiment extending over sixty years, and they have done this without a forkful of manure or a pound of purchased nitrogen. Why not? The wheat alone from eighty acres of land, if it yielded forty bushels per acre and sold at $1 a bushel, would pay nearly five per cent. interest on $300 an acre for the entire two hundred and forty acres used in my suggested rotation.
Aye, but there is one other very essential requirement: To wit, a world of work.
Hoping to hear from you, and especially about your alfalfa, I am,