Nitrogen Will Leed Us

by GRANT CANNON

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MOST of us, if asked, would say that the population of the United States is 150 million. We would, of course, be wrong. To get that figure, we rounded off some 1.1 million from the 1950 census estimate to make it easier to remember; then, we overlooked the fact that we are growing at the rate of more than 6000 persons a day or about the population of the State of Iowa each year. Every 9 seconds a new baby comes squalling into our community, whereas we lose a person to death but once every 21 seconds; and every 2 minutes a bewildered immigrant steps across our border, while we have a departure but once in 17 minutes. The result: a net gain of one person every 14 seconds.

Today, we have around 158 million people. A conservative estimate gives us 175 million at the next census and over 200 million when we count again in 1970. Project the population a few years beyond this and you begin to wonder whether we shall be facing the fate that Malthus predicted for every growing country.

This is not to say that we are on the verge of starvation. The population of the United States would have to reach a billion before our cultivated acres per person even compared to the .39 acre per person in China today, so blessed are we in good land. It does mean, however, that we shall have to accelerate production if we want to continue eating our high-protein meat diet and not slip to the cereal diet of the Orient.

During the past fifty years our food supply has kept pace with our more than doubled population and even piled up surpluses because of three important agricultural developments. We have increased our crop land by 10 per cent by land clearing and drainage and, more recently, by such difficult and expensive irrigation projects as Boulder Dam and Grand Coulee. We have switched to tractor agriculture and reduced our grain-eating horse and mule population from a high of 26 million to less than 6 million. And we created hybrid corn, which has meant an increase in production of this, our largest, crop of around 20 per cent.

But we have pretty well exhausted the possibilities of at least two of these aids. Hybridization is being used to increase production of crops other than corn, but the horse and mule population can’t shrink much more without endangering racing and western movie making, and the amount of land which we can still bring under cultivation is extremely limited. We have considerably more land under cultivation than any other country in the world today, and we have just about reached the limit of expansion. A diminishing water supply and rugged topography will make new land a most expensive commodity. As a matter of fact, though we have increased our tillable land by 10 per cent during the last fifty years, we have been slipping backward during the last ten of them, losing land to cities, highway construction, airports, industry, and to erosion. Our best hope for feeding ourselves in the future is to increase production on the land we have and to make better use of the food we produce. Our most important tool in accomplishing this will undoubtedly be nitrogen — both as a fertilizer to help us produce more food and as an actual feed for ruminants to help us stretch our supply of animal feeds.

Nitrogen is a colorless, odorless, inert gas which is needed by every living thing, whether plant or animal, for its existence. There is plenty of it. Around 80 per cent of the atmosphere is nitrogen — it has been estimated that there are 20 million tons of it over each square mile of the earth’s surface. But to be useful in agriculture or to man in industry or as an explosive, the nitrogen must be fixed — that is, combined with some other element such as hydrogen or oxygen. Natural forces have been fixing nitrogen since the beginning of life on this planet and even before that, and now man has learned how to fix it synthetically.

Every flash of lightning fixes in the atmosphere nitrogen which later falls on the earth with the rain. Someone figured that this celestial electric arcing fixes every day some 50 tons of nitrogen which falls upon the sea and the mountains and deserts and on the 7.7 per cent of the land which is suitable for farming.

Nitrogen is also fixed in the earth by bacteria and molds which live in the soil. Some of these microscopic soil-dwellers fix the nitrogen directly in the soil; others, the more important group, go from the soil into the roots of legumes — beans, peas, alfalfa, and the clovers —and convert the roots of their hosts into storage houses for nitrogen. All plants, except such drones as mistletoe and orchids and the parasites, take nitrogen from the soil and incorporate it into the cell structure of their leaves and stems and, in a more concentrated form, in their seeds. Animals which eat the plants concentrate the nitrogen still further in their bodies, for nitrogen is the essential element of all protein, whether of plant or animal origin.

Both plants and animals in their natural state eventually return the nitrogen which they have used to the soil. This would seem to create a situation in which we had an ever-increasing supply of nitrogen in the soil, and it would be so except for two factors. There are denitrifying bacteria which spend their time unfixing nitrogen and releasing it back into the air; and the water which flows over the earth and percolates through it carries away the nitrogen in solution to dump it into the sea. Man has joined in with his modern sewage disposal and washes millions of tons of nitrogen into the sea every year.

In a few spots on earth the naturally fixed nitrogen has collected into concentrated deposits. The most important of these is in Chile, where sodium nitrate, called Chile saltpeter, is found in a great yellowish strip two miles wide and several hundred miles long. From 1840 until the First World War the exporters of saltpeter held a virtual world monopoly of the nitrate supply. They were challenged feebly by the relatively small but constant supply of nitrogen which is recovered from coal as a by-product of our coking ovens. Once we learned how to fix nitrogen synthetically, this monopoly was broken forever.

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NITROGEN was first fixed synthetically in 1774 by the English chemist, Joseph Priestley, who created nitric acid by passing an electric spark through air which was confined over water. Priestley was duplicating the natural fixation of nitrogen by lightning — though he was not aware of t his at the t ime. Over a century later, this arc process of nitrogen fixation was begun commercially in America at Niagara Falls and in Norway, where abundant electric power made the process possible, though cost ly.

A second process was developed by the French chemist Moissan and was first used on a large scale in Italy in 1906. This method, called the cyanamid process, fixes nitrogen by blowing air through extremely hot calcium carbide to form calcium cyanamid. This process is only slightly less expensive than the arc method and has been virtually abandoned.

It was not until 1912 that Fritz Haber, the German chemical genius, discovered the process which is in common use today. His finding, which was developed in complete secrecy, freed Germany from her dependence on the Chilean deposits and the shipping problems involved in securing saltpeter and made it possible for her to launch World War I. After 1918, the Allies, who had gone through the war running the German submarine blockade to secure nitrates from Chile or fixing nitrogen by the more expensive methods — as we did at Muscle Shoals — acquired the Haber process. Haber himself, incidentally, went on to develop a process for extracting gold from the sea which, had it been successful, would have paid off Germany’s reparations in short order.

The Haber process consists of mixing specially purified nitrogen gas from the air with hydrogen to form ammonia. The mixture is made at very high temperature and under several hundred atmospheres pressure in the presence of an iron catalyst. From this stage the ammonia can then be used to form many other nitrogenous compounds.

Short ly after the war (World War I) Allied Chemical and Dye Corporation, whose chemists, along with many others in the world, were working toward the same solution to the nitrogen fixation problem which Haber had reached earlier, built the first ammonia plant in America at Syracuse. Du Pont, American Cyanamid, and other chemical concerns also moved into this vital field, and by the beginning of World War II we were fixing around 400,000 tons of nitrogen a year. Expansion during the war increased our capacity by over 300 per cent to 1.4 million tons of nitrogen a year in the form of ammonia. Korea and the cold war brought a further expansion of our plant and by 1951 we were fixing 1.65 million tons with a goal of 2.9 million tons w ithin the next few years. Some idea of the size of this development is given when we realize that for every ton of nitrogen produced in a year, industry has a plant investment of some $250.

Even this enormous fixation capacity and the vast investment it will finally take to produce it will only begin to fill our future need for nitrogen. As we have increased our fixation capacity, the demand for nitrogen in agricult urc has more than kept pace with that portion of the supply which was allotted the farmers from the defense program. In Indiana, for example, consumption of nitrogen has gone up 700 per cent in the last seven years; in some sections of the state, farmers are using eleven times as much as they did back in 1946. If all farmers in America began using nitrogen at the rate Yontz Bonnett, an Illinois corn grower, and Roswell Garst , an Iowa hybrid corn raiser and cattle feeder, find effective and profitable, 3 million tons of nitrogen a year wouldn’t be enough to fill the needs of Illinois and Iowa, let alone the rest of the country.

Bonnett, who has his 360-acre farm in a rotation of corn, corn, corn, and more corn, shreds the cornstalks in the field after he has harvested the crop and then plows them under with a heavy application of fertilizer. The nitrogen which he puts on in the fall feeds the soil bacteria so well that they are able to work on the stalks and reduce them to humus. In the spring, Bonnett plants his corn and adds another heavy application of fertilizer. Later in the summer, he side-dresses the crop with still more fertilizer. During the year Bonnett applies enough fertilizer to supply each acre with 150 to 200 pounds of nitrogen. This fertilizer program has enabled him to grow such a large crop and plow such a huge amount of cornstalk trash back into the soil that, after five years of continuous corn, his soil is more fertile and has a higher humus content than it did when he started.

Roswell Garst, who farms the rich rolling land around Coon Rapids, Iowa, goes Bonnett one better — he uses as much nitrogen as Bonnett does on his corn production and he also uses nitrogen, in the form of urea, to supply almost all of the protein in the feed of 6000 steers in his feed lots.

Nitrogen is not, of course, the only element needed to make a crop. It is, however, the first of the three major elements — nitrogen, phosphorus, and potash — and of a score of minor elements. Though any of these elements can limit crop production, nitrogen is the one most generally in short supply. Until recent years, our agricultural advisers have been making the same recommendations as those given to Roman farmers by Pliny the Elder — plant legumes and let them fix nitrogen in the soil. It has only been in the last few years that we have had enough synthetic nitrogen to make it worth while for our soils men to bother making recommendations as to its application. The recommendations which the agronomists now make are keeping the demand for nitrogen at an all-time high. When farmers found that a pound of nitrogen costing them around 12 cents would produce an extra 30 pounds of grain which they could sell for around a dollar, they were not slow in following the advice.

Yontz Bonnett has produced 117 bushels of corn per acre for the last five years in Illinois, where the average production is 51 bushels. Roswell Garst produced 65 bushels per acre by heavy applications of fertilizer on a worn-out farm which had not yielded a crop worth the harvesting for years, and he consistently produces around the 100 bushels to the acre mark on his good land. These are two of our hundreds of corn product ion records which make us feel that an abundant supply of nitrogen is the key to our future food supply.

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WE HAVE been talking about the production of corn, a sturdy crop w hich can stand a lot of fertility and which demands 2.5 pounds of nitrogen for each bushel produced. Wheat and the small grains are another problem. These grasses produce their seed at the top of a thin, rather brittle, stalk. When grown on very fertile soils there is the danger that the heads of grain will be so heavy that the stalk won’t support them and they will fall to the ground where only a small part of the crop can be harvested. The answer to this problem of lodging lies with the plant breeders.

“The new frontier of agriculture is fertility,” Dr. C. M. Caldwell, one of the nation’s outstanding plant breeders, has said. He and his associates have pushed into this unknown area by producing Vigo, a new, high-yielding wheat which can be grown on very fertile soils without danger of lodging; and they are now working on a new, short-stemmed variety which holds promise of pushing beyond Vigo. At the colleges and agricultural experiment stations in Washington, Montana, Nebraska, and Kansas, plant breeders are developing other varieties of wheat, oats, barley, and rye which will fit the particular conditions of these grain-growing areas. When fertilized with high nitrogen content fertilizers, some of these new wheats have produced 50 and 60 bushels to the acre as compared with the scant 13 which is the national average yield for wheat.

One of the most significant developments in the whole field of animal feeding since the time man first domesticated animals has been the discovery that we can feed a synthetic nitrogenous compound, urea, as a replacer of protein in the ration of our ruminants. Protein, which is essential in the diet of every animal, is 16 per cent nitrogen. Here, quite literally, we are taking feed from the air, combining it with our cheapest and most abundant vegetable produce, cellulose, and converting it into milk and wool and meat. When fully exploited in the rations of dairy cattle, beef cattle, and sheep, this discovery will release thousands of tons of soybean meal, cottonseed cake, linseed meal, and other proteins which can then be fed to our chickens and hogs. This now feeding technique is based on the discovery that the billions upon billions of bacteria which live in the rumen, or first stomach, of cattle sheep, goats, deer, camels, and the other members of the paunch-carrying family can take the nitrogen of urea and synthesize it into a protein which the animal then digests.

In effect, we are pouring the raw materials — nitrogen, sugar, starch, cellulose—into the bubbling fermentation vat which is the rumen, where the bacteria convert them into the usable proteins and carbohydrates needed by the animal. We feed the bacteria and they feed the cow. Apparently the bacteria are also able to synthesize many of the necessary vitamins (B12 — the vitamin which is a distinguishing factor between animal and vegetable proteins — was once known as the cow manure factor because cattle synthesize such large amounts of it that significant quantities were recoverable from their manure).

Roswell Garst was one of the first farmers to begin commercial cattle feeding with urea. “My conversion to urea,” Garst has said, “ began when I got to thinking about the general problem of protein and cellulose. I began by wondering why grass was such an excellent feed in the spring when it was young and green and such a poor feed in the fall when it was dry. I did a little reading and found that the only difference between the young and the old grass is that in the spring the grass has about 16 per cent protein and the dry grass is almost pure cellulose. So, I hit on a formula which went like this: ‘Cellulose, in combination with protein — and only in combination with protein — makes an excellent feed for ruminants.’ And what is cellulose? Why, just corncobs and cornstalks and straw and bagasse and all of the other plant material which we can produce in unlimited quantities and which we have been treating as a refuse.”

This was a most stimulating thought for a man whose hybrid corn business produces a mountain of corncobs every year which, in the old days, were burned or at best used for cattle bedding. Garst’s formula was given real significance when he learned of the cheap source of protein, urea, which was just then being used in cattle feeding experiments by the late Paul Gerlaugh and by Wise Burroughs, W. M. Beeson, Gus Bohsted, and other animal nutritionists. Garst decided to do a little experimenting himself. He began by penning off a few head of cattle and feeding them ground corncobs, molasses, and protein supplement which was about one-third urea and the rest high-quality vegetable protein. In a second pen he fed other cattle cob meal, molasses, and a protein supplement which was half urea. Both pens did well. “At that time it was felt that too much urea would poison the cattle, as it will nonruminants, or as it will cattle if it isn’t properly mixed, and we just didn’t have the guts to push our ration beyond the half-andhalf stage,” Garst recalls.

The following winter Garst put 1800 head of Western steers on a feed of ground corncobs, molasses, and a protein supplement which was half urea. “I put the molasses in because I felt that the steers would rather eat corncobs and molasses than they would dry cobs, just like I’d rather have some molasses on my hot cakes,” Garst said. This intuitive feeling for what a steer finds palatable was particularly fortunate. The Iowa nutritionist, Wise Burroughs, has since conducted a number of tests in artificial rumens which show that without the molasses to give them a quick source of energy, the bacteria wouldn’t have taken to the dry cobs and urea with any enthusiasm either.

Garst has since stepped up the numbers of cattle he feeds and has increased the proportion of urea to natural protein. He feels that it may be possible to feed a ration in which urea replaced all of the natural protein other than that contained in the corncobs or other cellulose roughage. A number of leading nutritionists agree with Garst and also agree with him that a great deal more experimenting should be done in this matter.

With a national population of over 94 million dairy and beef cattle and with around 30 million sheep, the savings in animal feed which cellulose and urea feeding will effect will be like adding millions of acres of land to our country. W ith this additional food supply and with the increased production which we can achieve with nitrogen fertilizers, it looks as though we shall be able to continue to grow and to cat well, too, for a time. But at the rate we are growing we shall have to make full use of nitrogen and all of the other production stimulants to keep up.

Does this mean that we will never have a surplus again? As far as individual crops are concerned, the answer is no. Through shifts of acreage to any one crop, we may occasionally pile up a surplus. And then there are crops, like potatoes or cotton, which may be in oversupply because of shifts in our food habits and in our synthetic fabrics. Or situations like the one last year may occur, when a drought caused large numbers of farmers to sell cattle because of a feed shortage and cattle and beef prices were forced down. But as far as the total food supply is concerned, we are in no danger of overproduction. A depression might make it difficult for us to buy what we produce, but our ability to consume all that we can grow will go on unimpaired.

Last year, with bumper crops, we imported more food than we exported for the first time in our history.