and it is safe to say that a large majority of the farmers of the United States gladly hold to the erroneous theory that clover grown once every three to five years will increase and permanently maintain the fertility of the soil.

The fact that clover was grown for generations on the lands of the older Eastern states until the clover crop itself finally failed on millions of acres now agriculturally abandoned is overlooked or forgotten by present-day farmers, especially by the descendants of those who have gone West and settled on new, rich lands.

Six Facts and a Question

The following six facts will furnish a comprehensive basis for the solution of the nitrogen problem in practical general agriculture:

(1) To produce 100 pounds of grain requires about 3 pounds of nitrogen, of which 2 pounds are deposited in the grain itself and 1 pound in the straw or stalks.

(2) In live-stock farming one-fourth of the nitrogen in the food consumed is retained in the animal products—meat, milk, wool, and so on—and three-fourths may be returned to the land in the excrements if saved without loss.

(3) When grown on soils of normal productive capacity legumes secure about two-thirds of their total nitrogen from the air and one-third from the soil.

(4) Clover and other biennial or perennial legumes have about two-thirds of their total nitrogen in the tops and one-third in the roots, while the roots of cowpeas and other annual legumes contain only about one-tenth of their total nitrogen.

(5) Hay made from our common legumes contains about 40 pounds of nitrogen per ton.

(6) Average farm manure contains 16 pounds of nitrogen per ton.

Question: How many tons of average farm manure must be applied to a 40-acre field in order to provide as much nitrogen as would be added to the soil by plowing under 2-1/2 tons of clover per acre? Answer: 400 tons.

Either method will furnish about as much nitrogen as would be taken from the soil by a 50-bushel crop of wheat, a 75-bushel crop of corn or a 100-bushel crop of oats per acre. The decision by the individual between live-stock farming and grain farming should be based upon preference and profit rather than upon the erroneous teaching that farm manure is either essential or sufficient for the maintenance of soil fertility in this country.

Bread is the staff of life, and many must sell grain. I do not advise all grain farmers to become live-stock farmers; but I do advise both grain farmers and live-stock farmers to enrich their soils by practical, profitable and permanent methods. Both classes of farmers may secure new nitrogen—that is, they can positively increase their nitrogen supply by sufficient use of legume crops.

How to Supply Nitrogen

The cotton-grower who sells cotton lint at 10 cents a pound and the market gardener who sells from $100 to $300 worth of fruits and vegetables from one acre may well make liberal use of commercial nitrogen at 15 or 20 cents a pound; but if after deducting the cost of harvesting, threshing, storing and marketing the average farmer receives only 1 cent a pound for his grain and if 40 per cent of the commercial nitrogen applied is lost by leaching, then the total crop of grain would bring only enough money to pay for the nitrogen required to produce it, at 20 cents a pound. We may sometimes advise the American grain-grower to buy water with which to irrigate his crop, but not to buy nitrogen with which to fertilize it.

If the grain farmer grows 40 bushels of wheat to the acre, clover having been seeded on the same land in order to plow under the equivalent of 1-1/2 tons of hay as green manure the following spring, and follows this by a 60-bushel crop of corn and a 50-bushel crop of oats, and this the fourth year by two crops of clover aggregating 3 tons an acre, including 2 bushels of seed, he can thus secure from the air about 180 pounds of nitrogen in the 4-1/2 tons of clover. Moreover, if the first cutting of clover the fourth year is left on the land and the threshed clover straw from the seed crop and likewise all straw and stalks are returned to the soil, only 154 pounds of nitrogen an acre would leave the farm if the total grain and clover seed were sold. With 80 cents a bushel for wheat, 50 cents for corn, 40 cents for oats and $8 for clover seed, the total returns from the four acres would amount to $98.

On the other hand the live-stock farmer may grow two 60-bushel crops of corn, followed by 50 bushels of oats and then 3 tons of clover hay containing 120 pounds of new nitrogen. The four crops would contain 350 pounds of nitrogen; and if the grain and hay and half the corn-stalks are used for feed, with the straw and the remainder of the stalks for bedding, it is likewise possible to replace the 230 pounds of nitrogen required for the grain crops, provided not more than one-seventh of the manure is lost before being returned to the land. The important weakness on the common live-stock farm lies in the enormous waste of manure.

If 10 pounds of feed produce 1 pound increase in the live-weight of the animals fed, and if they bring 6 cents a pound on the hoof, the gross returns aggregate $107.50 from the four acres, barring losses from accidents, animal diseases, and so on.

Thus, with a few established facts in mind, one can easily determine how to maintain or even to increase the supply of nitrogen in the soil, and without the purchase of nitrogen in any form; and it is just as possible and just as necessary thus to provide the nitrogen needed in grain farming as in livestock farming. When we consider that animals destroy two-thirds of the organic matter in the food consumed we find that as between the two systems above described the organic matter or humus of the soil will be better maintained in the grain system outlined.

Live-Stock or Grain Farming

For those who believe that live-stock farming must be adopted for the maintenance of fertility on all farms, attention should be called to the fact that there are 900,000,000 acres of farm-land in the United States and only 90,000,000 head of live-stock equivalent to cows, including all farm animals. Will the manure from one cow serve to enrich 10 acres of land?

It should also be known that a hundred bushels of grain will support five times as many people as could live for the same length of time on the meat and milk that could be made by feeding the grain to domestic animals. It is because of this fact that the consumer may sometimes boycott meat or other animal products, while he never boycotts bread; but let us hope that permanent systems will become generally adopted in America, for the production of both grain and live stock, so that high standards of living may be maintained for all classes of people in this country.

The oldest direct comparison between these two systems of farming, so far as the writer has learned, is on the experiment fields of the University of Illinois, where as an average of six years the yield of corn has been 87 bushels an acre in grain farming and 90 bushels in live-stock farming, the same crop rotation being practiced. Where wheat was introduced the average yield for six years was 43.1 bushels in grain farming and 43.5 in live-stock farming.

No nitrogen was purchased in any form in either of these systems; but clover is grown in the rotation to secure nitrogen from the air and then the crop residues or farm manure is returned to the soil to provide sufficient nitrogen for the grain crops. In all cases phosphorus was used for these yields.

Even more encouraging than these six-year average results from Illinois are the results of sixty years from Agdell Field at Rothamsted.

Where mineral plant food was regularly applied, and where all the manure produced by feeding the turnips was returned to the soil, in a four-year rotation of turnips, barley, clover (or beans) and wheat, with no other provision made for supplying nitrogen,