--- title: Improvement Era description: Monthly periodical of the Mormon church, 1897 onward. This library holds the issues of November 1897 to December 1930. authors: - Greaves, J. E. collections: - periodicals tags: - magazine - improvement-era periodical: Improvement Era volume: 32 number: 12 published: 1929-10 publisher: Young Men’s Mutual Improvement Associations publisher_place: Salt Lake City language: en type: magazine reference: "J. E. Greaves, “The Sulfur Cycle,” *Improvement Era* 32, no. 12 (October 1929): 990–996." source: url: https://archive.org/details/improvementera32012unse transcription: Transcribed from the Internet Archive scan of each issue (the item for each issue is named in the issue's own source); unnumbered advertising leaves are omitted, printed page numbers are kept as page markers. identifier: improvementera32012unse start_page: 990 end_page: 996 rights: status: public-domain basis: US publication 1930 or earlier (published 1929-10) source: https://archive.org/details/improvementera32012unse publication_year: 1929 note: The Internet Archive item metadata carries a blanket "© Copyright by Intellectual Reserve, Inc." notice. The library owner judged it inapplicable because this issue was published in 1929, before 1931; a scan-level notice does not restore copyright. --- # The Sulfur Cycle The Sulfur Cycle J. E. Greaves, Utah Agricultural College THE persistent search of the scientist has revealed to date only 92 elements, in earth, air, water, and every living thing in- habiting them. Some of the elements are rare, others are abundant. We believe today that everything in this entire universe is composed of atoms which are ever changing from one combination to another. Plants and animals, men and women, are an "ever- shifting," ever- varying swarm of atoms, every mechanical work of earth, air, fire, and water, every criminal act, every human deed of love or valor. What is it all, pray, but the relation of one swarm of atoms to another? "Here, for example, is a swarm of atoms, vibrating, scintillant, martial — - they call it a soldier — and anon, some thousands of miles away upon the South African veldt, that swarm dissolves, forsooth, because of another little swarm — they call it lead. "What a phantasmagoric dance it is, this dance of atoms! And what a task for the master of ceremonies! For, mark you, the mutabilities of things. These same atoms may come together again, vibrating, clustering, interlocking, combining, and there results a woman, a flower, a black bird, or a locust, as the case may be. But tomorrow again the dance is ended, and the atoms are far away; some of them in the fever germs that broke up the dance, others are the green hair of the grave, and others are blown about the Antipodes on the wings of the ocean, and the eternal everchanging dance goes on." This journey of the atoms through the living and the dead is a complex process followed imperfectly even by the chemist of today with his apparently magic methods. Two elements, sulfur and nitrogen, are of intense interest. The cycles of these elements have much in common. They journey through earth, air and water, occurring both in the organic and inorganic forms. Native nitrogen occurs in the atmosphere, native sulfur in soil and water. Sulfur and nitrogen find their way into the atmosphere through combustion and decay; they both are rendered available to the growing plants through biological processes. Animals require both nitrogen and sulfur in the organic form. A vast amount of work has been done on the nitrogen cycle, much less on the sulfur cycle, due to the different values which have been assigned to the two processes. However, modern discoveries have given to the sulfur cycle new in- terests: (1) Recent methods of analyses have shown that sulfur constitutes a greater proportion of plant and animal tissues than was formerly believed to be the case. (2) Soils have been found which contain insufficient sulfur to meet the needs of the growing plants. Oct.. 1929 THE SULFUR CYCLE 991 (3) It has been learned that sulfur often plays an indirect role in the liberation of other plant-food. Sulfur Everywhere SULFUR constitutes 0.08 per cent of igneous rock. It is esti- mated that 0.12 per cent of the earth is sulfur, where it occurs in both the free and combined form. Large deposits of free sulfur are found in Sicily and Japan, as well as in Louisiana and Texas, and other parts of the United States. Soils contain it in rather small quantities both in the organic and inorganic forms. Inorganically, it occurs mainly as sulfates combined with calcium, magnesium, sodium, and other common bases. Its origin is the native rock, organic manures, and rain water. It is emitted in all volcanic regions, and sulfur springs contain it in large quantities. Sulfur is essential for the life of plants and animals. It is necessary for the production of certain essential oils and enters into the composition of the bodies of all plants and animals. Wool, horn, and hair are especially rich in it. In these it occurs primarily in the organic form of proteins; and proteins are composed of some nineteen amino acids, one of which, cystine, carries sulfur. The amino acids are essential for the building of animal tissue, and with the exception of one, glycocoll, must be received pre-formed in the diet of the animal. The animal cannot build them. They are synthesized by the plant, and it is from the plant, either directly or indirectly, that the animal obtains them. In fact, the extent to which tissue can be produced by any animal is governed by the quantity and proportion of the specific amino acids in the diet. Consequently, an animal cannot grow unless eighteen of the nineteen building blocks, the amino acids, are supplied in the food. As previously stated, horn, hair, and wool are extremely rich in sulfur where it occurs in the amino-acid, cystine. Eleven per cent of wool is cystine, a little over one-fourth of which is sulfur. Scoured wool carries as an average 3.4 per cent sulfur; consequently, sheep must receive at least 0.34 pound of sulfur, which must be supplied as 1.36 pounds of cystine for every one hundred pounds of wool which they produce. This must be supplied in the form of protein sulfur as the animals cannot use the inorganic sulfur. For these reasons Robertson has concluded that apart from possible mineral deficiencies which vary from place to place and must be ascertained separately for each, the carrying capacity of any country for sheep may obviously be determined by either of two factors, namely: "(1) The total nutritive value of the fodder plants per acre, or the 'energy value' of the pasture, and — 992 IMPROVEMENT ERA Oct., 1929 "(2) The cystine production per pound of fodder protein, which, for wool production, constitutes the 'biological value' of the pasture. "Where cystine production is high the energy value of the pasture will limit its carrying capacity; where cystine production is low the biological value of the pasture will form the limiting factor. In the former case the introduction of pasture plants of high energy- value, without much regard to their productivity of cystine would improve the pasture. In the latter case the introduction of fodder plants of high cystine productivity irrespective of their nutritive value (apart from this amino-acid) would similarly improve the pasture." The quantity of sulfur occurring in Utah-grown grains has been found to vary with the specific grains, the water applied during the growing season, and the soil on which it is grown. Table I. Percentage Sulfur in Wheat, Oats, and Barley Grown Under Varying Conditions Wheat Oats Barley Maximum _ _ 0,287 0.204 0.120 0.294 0.190 0.115 0.241 Average 0.155 Minimum 0.082 The variation in sulfur which preliminary work indicates can be attributed to irrigation water is 48 per cent; to variety, 40 per cent; and to soil, 30 per cent. If later work shows this increase of sulfur to be organic, grains grown under one condition may be twice as valuable for wool production as grains grown under differ- ent conditions. From these and other results the quantity of sulfur removed from the soil by the growing crop can be calculated. This has been done and is given for a few of the common crops in Table 2. It is evident that the sulfur content of plants and the quantity removed annually from the soil varies widely with the size and kind of crop. A 300-bushel crop of potatoes removes only five pounds, whereas an 8-ton crop of alfalfa removes 52.8 pounds. One ton of alfalfa carries twice as much sulfur from the soil as does one ton of peas. Consequently, alfalfa rapidly depletes the soil of sulfur, yet its value, for the production of wool, is twice that of peas or timothy hay. Oct.. 1929 THE SULFUR CYCLE 993 Table 2. Pounds of Sulfur Removed From an Acre of Soil by Maximum Crops Crops Sulfur (lbs.) Corn Grain (100 bu.) Corn Stover (3 tons) .. Total Crop Barley Grain (100 bu.) Barley Straw (2.5 tons) Total Crop Oats Grain (100 bu.) Oats Straw (2.5 tons) Total Crop Alfalfa (8 tons) Peas (4 tons) Sugar-beets (20 tons) __ Potatoes (300 bu.) ____ 9.5 7.6 17.1 7.4 7.4 14.8 6.1 6.0 12.1 52.8 13.6 13.0 5.0 The sulfur contained in the crop comes from the soil; therefore, it is imperative to know the quantity of sulfur in the soil if an estimate is to be made of the durability of the soil. In Table 3 is given the maximum and minimum quantities of sulfur reported for different soils. Table 3. Maximum and Minimum Quantities of Sulfur Reported for an Acre Foot of Soil (3. 600,000 Pounds) Locality Minimum Maximum Utah 252 297 660 700 720 828 900 972 666 1,764 Missouri 1.067 Wisconsin ___ __ 2,000 Iowa 900 Oregon _ 1.200 Nebraska Kentucky 2,526 2,340 Kansas 1,656 Tennessee Average 1,850 Average Eastern part of the United States _._. 1.440 General Average 1,764 994 IMPROVEMENT ERA oa. i9Z9 The variation in the sulfur content of different soils is very great; in some there is abundance, in others it is near the danger; limit, as is evident from a simple calculation. Two hundred and fifty-two pounds of sulfur, the quantity found in some Utah soils, is sufficient for only five annual maximum crops of alfalfa were the plant able to take all the sulfur from the first foot section of soil. The highest sulfur-carrying soils in Utah would last only 33 years. The average durability for the soils of the United States is from 13 to 33 years. Where wheat, oats, barley, peas, and sugar-beets are grown the durability of the soil would be from three to five times longer. These illustrations show how serious would be the sulfur problem were it not that the soil is constantly obtaining small quantities of sulfur from other sources. Combustion and decay con- stantly liberate gaseous sulfur compounds. Millions of tons of sulfur are thrown into the atmosphere by volcanoes and from chim- neys, especially from some manufacturing plants. This sulfur finds its way back into the soils, oceans, lakes, and streams of the country. The quantity of sulfur brought to the soil by precipita- tion varies from 3 to 131 pounds per acre annually, being high near manufacturing centers and low in the country. The average for eighteen localities in various parts of the world was 34 pounds. From the standpoint of soil fertility, these figures are misleading, as the majority of the determinations was made near centers of thick population where industries send large quantities of sulfur into the atmosphere, consequently, much appears in the precipitation. It has been found through a study extended over four years that the pre- cipitation on the campus of the Utah Agricultural College brings 33 pounds of sulfur to each acre of soil annually, where as the average over the same period for eight country localities was only 9.5 pounds of sulfur per acre. A careful study of all available data leads to the conclusion that this latter figure represents approximately the quantity brought annually to agricultural soils by precipitation. The quantity of sulfur discharged into the sea is enormous. The salts of its waters contain about 7.69 per cent of the sulfate radical; consequently, one would expect some sulfur returned to soil by irrigation waters. An analysis of 46 of the principal irrigation streams of Utah bears out this expectation. Sulfur From Irrigation Waters EMERY CREEK carries 676 pounds of sulfur in an acre-foot of water, Price River, Huntington Creek, Sevier River, Jordan River, and Ferron River all carry over 200 pounds of sulfur in an acre-foot of water. None of the lands irrigated with these waters Oct.. 1929 THE SULFUR CYCLE 995 would become deficient in sulfur. However, these waters are high in alkali salt and, due to their high salt content, may be injurious. The waters of five streams and one lake tested contained between 100 and 200 pounds of sulfur in an acre-foot of water; seven others carried between 50 and 100 pounds. Twenty-seven streams carried less than 50 pounds of sulfur in an acre-foot of water. All but two of these carried less than 25 pounds; consequently, very ap~. preciable quantities of sulfur are carried to the soil by some irrigation waters. The quantity varies greatly with the streams. Some waters furnish sufficient for the production of maximum irrigation crops of heavy sulfur-requiring plants, other waters would not carry suf- ficient quantities yet would assist in maintaining the sulfur content of the soil. The principal streams of the Cache Valley region, Cub River, Logan River, and Little Bear River, where the sulfur content of the soil is low, carry only small quantities of sulfur. Now, if we assume that the sulfur brought to Cache Valley soils annually in the precipitation is 9.5 pounds per acre and 7 pounds per acre annually in the irrigation water (the actual quantity found in the Logan River water, which is used on some of these soils), there would be an annual gain of 16.5 pounds. Where the Cub River water is used on these soils there would be an annual gain of only 12.5 pounds. Where barnyard manure is used another pound would be added with each ton of manure. It is, therefore, likely that the sulfur brought to the soil annually by precipitation, irrigation water, and manure would be about sufficient to account for the annual removal in such crops as wheat, oats, barley, corn, peas, and sugar-beets. When crops like alfalfa are grown, the incoming sulfur would not be sufficient to supply half the sulfur removed in the crop. From these results it may be concluded that where alfalfa is grown sulfur may become a limiting element in some of the Cache Valley soils, and that at a not-far-distant date, a conclusion which would likewise apply to sulfur-poor soils in other parts of the United States. In all of the preceding calculations no account has been taken of the sulfur lost in drain waters. The data compiled by Joffe show an annual loss of from 8 to 28 1 pounds of sulfur in the drain- age water. The quantity lost would vary with the kind of soil, the amount of precipitation, the system of cropping, and the methods of cultivation. If it is assumed that the annual loss from drainage is 1 5 pounds, the quantity found by Jones lost from some of the sulfur-poor soils of Oregon, and that the annual gain is 7 pounds that brought to the soil of the Central Experiment Station (Greenville) per acre in the irrigation waters and 9.5 pounds in the precipitation, there would 996 IMPROVEMENT ERA o«.,i9Z9 be 1.5 pounds per acre annually to supplement the native soil sulfur. Even with crops requiring only small quantities of sulfur this would not meet their need; and with some other crops, alfalfa, for example, it would be an insignificant quantity. Consequently, these results point to the conclusion that some of the Cache Valley soils will ultimately become deficient in sulfur. The time required for this to become evident will vary with the specific soil, the nature and the size of the crop grown, and the quantity of manure returned to the soil. From what has been said, it is evident that the sulfur cycle can be summarized as follows: Sulfur is a vital constituent of the bodies of all plants and animals and as these are burned, putrefy, or decay, the sulfur finds its way into the atmosphere. This is washed from the atmosphere in the rain and snow. In the soil the products are worked over by bacteria and combined with the bases to yield sulfates. These may be taken up by the growing plant or leached out by the waters and wander to the sea. The quantity of sulfates in the sea is enormous and one may well wonder why the sea is not mainly a sulfate solution. It is because sulfates are continually being reduced to sulfides. These react with iron and there results iron sulfide; or they may react with calcium and, as the water evapo- rates, deposits of gypsum result. From these, possibly through bacterial action, there is produced sulfur. The sulfur used by the growing plant is built into the plant tissue. This may be used by the animal and become a part of its tissue. The sulfur of the plant and animal tissue may be liberated through combustion, putrefaction, or decay, and again starts on its journey. Thus, a large part of the sulfur of the world is continually changing from sulfite to sulfate with local reversions to native sulfur and often to organic sulfur and back to sulfide and sulfate. What Great Men Have Said About The Bible "The Bible is the best book God has given to man." — Abraham Lincoln. "I am sorry for the man who does not read the Bible every day." ■ — Woodrow Wilson. "I remember the time when at my mother's feet, or on my father's knee, I learned to lisp the phrases of the Scriptures. If there is anything in my life to be commended, tha credit is due to my parents in instilling into my mind the sacred Scriptures." — Daniel Webster. "No one can justly claim to be educated, who is not familiar with the Bible's contents." — General Francis Green. West Point, upon presenting each graduate with a Bible.