LIBRARY OF THE MASSACHUSETTS AGRICULTURAL COLLEGE ourceUSJ S 633 G43 v*l .. c: CARD Digitized by the Internet Archive in 2010 with funding from Boston Library Consortium IVIember Libraries http://www.archive.org/details/stassfurtindustr01germ THE Stassfurt Industry Published By GERMAN KALI WORKS, NEW YORK, N. Y. ATLANTA, GA. ' CHICAGO, ILL. ^^ Nassau Street. 1224 Candler Building. 562 Monadnock Block. NOTICE. Every farmer ca7i obtain^ free of charge, a copy oj the following agricultural books: Peinciples of Profitable Farming, Potash in Agriculture, Farmer's Guide, Farmers' Note Book, Cotton Culture, Tobacco Culture, Orange Culture, Strawberry Culture, Tropical Planting, Fertilizing Tobacco, Sugar Cane Culture, The Cow Pea, Plant Food, Truck Farming, Why The Fish Failed, State which of the above mentioned publications you desire, and it will be mailed to you, free of charge. ADDRESS: GERMAN KALI WORKS, NEW YORK, ATLANTA, GA., CHICAGO, ILLS,, 93 Nassau Street, 1224 Candler Bldg., 562 Monadnock Blk., HAVANA, CUBA. Empedrado 30 PREFACE- THOUSANDS of American farmers use potash, Hun- dreds of thousands of them should use it, both for their own present and future profit and to prevent their posterity from receiving a heritage of "worn out" soils. But ashes — once the most common sourch of potash — are no longer to be had in quantity. Our forests are now cleared and the ash heap of the pioneer is a thing of the past, while wood as a fuel for factories and railroads has been replaced by coal and oil. Where, then, shall we turn? Man seldom feels a pressing and continuous need which Nature does not meet — and such has been the case with potash. Whithin the fifty years which measure alike a rapidly increasing demand for it and the practical dis- appearance of the old source of supply, there has been found, in one of Nature's storehouses, an inexhaustible accumulation of potash. To the discovery of the deposit the term fortunate can be applied, since it came in time to meet need; but the storing of the potash, when one con- siders the importance of this element, for the welfare of our fields and its necessity in maintaining the food supply for the rapidly increasing mouths of the world, the storing we must call Providential. The process of Nature, by which this accumulation was made possible, are marvellous, and the methods which man has devised to utilize the store and convert it into forms best suited to the diverse requirements of his fellows are ingenious. The many inquries which arise concerning potash in its varied forms, prove that its users are interested in its history; therefore, this little sketch has been prepared to meet the friendly wishes of those who already appreciate potash. The story is interest- ing and those who read it will derive pleasure and profit. HISTORICAL SKETCH. STASSFURT, near the Harz mountains in northern Germany, has been, for many centuries, noted for its salt works. There, in the early days of history, common salt was obtained by evaporating the water from its salt springs, and later, from its wells. When mines of rock salt were discovered in other places, the evaporation process was abandoned partly because the brine from the springs and wells, generally contained, beside table salt, the salts of potash and magnesia. Adout fifty years ago, the Prussian Government which owned the mines, began boring for rock salt, and in 1857 found it in immense quantities at Stass- furt, 1,080 feet below the surface. Immediately above this rock salt are deposits of various potash and magnesia minerals, at first considered of little value and actually thrown away as worthless, but later to supply the world with potash. The agricultural value of potash became generally known in i860, through the researches of that eminent scientist, Prof. Justus von Liebig, and in 1861 the first factory for refining crude potash minerals was estab- lished at Stassfurt. Stimulated by the success attained in the use of potash as a fertilizer, the industry of mining and manufacturing its salts has grown to enormous proportions; new deposits have been discovered and mines opened, until to-day there are about 45 large mining establishments in active operations. ORIGIISr OF THE STASSFURT SALT AND POTASH DEPOSITS, The Stassfurt salt and potash beds were formed (or deposited) in ancient, geologic times. Long before history began, these minerals were laid in place by the evaporation of sea water confined in lakes, which, somewhat like the Dead Sea and Baikal Lakes, were without outlet. These were connected, however, with the ocean by channels, or- dinarily dry, but through which the sea water was forced at times by great storms and tides. In this way fresh sup- plies of salt were received into these lakes, and as the cli- mate of Europe was tropical during this formative period, the surface evaporation of the water was exceedingly rapid. As the water levels of these lakes thus sank, fresh supplies washed in from the sea, holding in solution then, as now, many salts. Evaporation carries off only pure water, so, in course of time, as more salts were entering the lakes and none going out, the water became saturated with salts until those least soluble in water began to separate from the more soluble ones and deposit themselves in more or less uniform strata. By such continued evaporation and ever increasing concentration, immense layers of rock salt and anhydrite (sulphate of lime) were formed. As the rock salt separated and the concentration became greater, other more soluble salts began to deposit and cover Origin of the spassfurt salt and potash deposits. 7 it , layer upon layer, up through the mineral polyhalite, which is composed of sulphate of lime, potash and magnesia, — kieserit, which is sulphate of magnesia, — and the" potash region," the stratum of carnallit, a compound of chlorides of potassium and magnesium. This last named stratum ranges from 50 to 130 feet in thickness, and supplies the crude salts from which the most important and concentrated potash salts are refined. From thus referring to strata it does not follow that these deposits are in smooth, clear-cut layers. From time to time, as additional water came in from the sea, the lake water became so diluted that precipitation was arrested to a certain extent, and, later had to commence again; thus anhydrite is found in the rock salt strata, and seams of rock salt in the polyhalit and other upper layers. Potash and magnesia salts are the most soluble and, therefore, naturally found at the tops of the deposits. Had these deposits been exposed to the action of rain water they would have been dissolved, but they were pro- tected during geologic changes by a covering of " salt clay," impervious to water. Above this salt clay roof occurs a de- posit of anhydrite beneath a second deposit of rock salt, — a later formation and probably of recent origin, geologically speaking. The depth of the Stassfurt salt deposit, from the top of the upper to the bottom of the lowest stratum is some 5,000 feet. The beds underlie the extensive country reaching approximately to Thuringia on the south, to Hanover on the west and to Mecklenburg on the north. 8 ORIGIN OF THE STASSFURT SALT AND POTASH DEPOSITS. These deposits, in the order of their placing, follow well understood physical and chemical laws; and yet local con- ditions and geologic disturbances fixed the relative positions of strata and account for more or less apparent disturbances as shown by the diagram. At a few places surface water found access through cracks or fissures, and either carried away the potash salts or changed them into secondar}^ pro- ducts; from which action in the upper strata occur beds of kainit, sylvinit, hartsalz and other compounds of less im- portance. This description, somewhat tedious to unscientific readers, becomes of surpassing interest when the enormous importance of the formation is considered. But for these peculiar conditions at Stassfurt (conditions generally termed accidental) these potash deposits could not have been formed; and vast tracts of agricultural lands, now made fertile and productive by the use of potash from this in- exhaustible store, would be sterile and barren for want of it. There is no question as to this scientific fact, and thoughtful readers may well again peruse the story of these wonderful deposits and question whether a formation — all but a creation — of such importance to the human race, can be considered a mere chance, — a simple accident of nature. SECTIOxNf OF POTASH SALT MINE SHAFT " LUDVVIG II DESCRIPTION OF THE SALTS. Salt is the chemical name for a compound composed of an add joined to, or combined with, a base. For example, burnt lime is a base, which, in combination with sulphuric add, forms a sal^ called sulphate of lime; similarly the dase sodium combined with hydrochloric acid forms the sal^ sodium chloride. This last is the compound to which, popularly, the word " salt " is applied, for sodium chloride is our common table salt, but chemically the term is a general name for compounds produced as described above. The Stassfurt deposits contain various salts and com- binations of salts, many of which contain little or no potash. The following list gives those most important as potash producers, with their mineral names, and chemical formulae; Carnallit, KCl, MgCl2, 6H2O. Kainit, K2SO4. MgCb, 6H2O. Sylvinit, KCl, NaCl, K2SO4, MgS04, MgCb, 6H2O. Hartsalz, KCl, NaCl, MgS04, H2O. Upwards of thirty different minerals are found in the Stassfurt deposits, of which some twelve contain more or less potash. The four above named yield the main supply of commercial potash, and of these the first three are most important. Carnallit, which is the chief source of muriate of potash and other concentrated salts, usually occurs mixed with DESCRIPTION OF THE SALTS. II rock salt and other minerals in layers averaging more than 85 feet in thickness. The color varies, and shades through white, bright to dark red, yellow, and light to dark gray, to a watery hue. In a strong clear light the brilliancy of carnallit crystals and their varied colorings give to its, mine galleries a strikingly beautiful effect. Carnallit as mined contains about 9 per cent, of actual potash. In its crude state it is used as a fertilizer only in localities which are not very far from the mines; because from its property of absorbing water, and its bulk as compared with the small percentage of potash which it contains, it is more expensive than the concentrated salts, where cartage or freight has to be considered. The deposit of carnalit is generally in- tersected by rock salt and often by other minerals, and is so vast in extent as to be practically inexhaustable. Kainit, a mineral compound of the sulphates of potash and magnesia with magnesium chloride, is not found in the same abundance as carnallit, but nevertheless in such quantities as to meet all probable needs for many gen- erations to come. It occurs in large, irregular deposits, and, as mined, is usually red and more or less mixed with rock salt, of which it contains about 30 per cent. In its crude state it is largely used as a fertilizer, after being crushed and ground, and contains at least 12.4 per cent, actual potash (K2O). This percentage of potash in kainit is guaranteed, but the materials with which it is mixed or blended differ more or less according to circumstances. Most of the kainit mined is sold in its natural state for 12 DESCRIPTION OF THE SALTS. fertilizing purposes, although a considerable part is used in the manufacture of high grade sulphate of potash and other concentrated products. In some mines, especially those more recently opened, instead of kainit is found the so-called hartsalz or hardsalt, a mixture of muriate of potash (sylvine), kieserit and rock salt. Hartsalz shows much the same chemical composition as kainit, and though differing from it in chemical structure, is, for most purposes, identical with it. Sylvinit, although of more recent introduction than either carnallit or kainit, like carnallit is not generally sold in the United States, is in the main, a mixiure of sodium and potassium chloride or rather, of sylvine and rock salt with a little kainit and contains, on an average, 14 to 18 per cent, actual potash in the form of chloride (muriate). It is finely ground for use as a fertilizer, or is manufactured into concentrated potash salts. Of these four crude potash salts only kainit and hartsalz are used in the United States; On account of the freight rates the results obtained from the concentrated forms of potash pay better. Kainit is extensively used in the Coast Line States, not only as a fertilizer, but also as a manure preservative, to check attacks of injurious insects, and as a remedy against cotton disease (blight). For such purposes it is cheap and satisfactory and likely to be used in in- creasing quantities. MINING THE SALTS, The potash-bearing strata, from 1,200 to 2,500 feet below the earth's surface, are reached by ordinary mine shafts. In sinking these shafts, great care is taken to preserve un- broken the cap materials impervious to water, and thus to prevent the highly soluble potash-bearing salts from being rapidly leached or washed away by the surface waters. This inflow of water is made impossible by sinking iron tubes or lining the shafts with concrete. Water is the great danger in potash mining, and has destroyed valuable mines. Generally potash mines have a reserve or emerg- ency shaft, some distance from the working shaft, protected by strong safety -pi liars. Another mining difficulty is the ' ' pillaring ' ' or supporting the mine-roof as its mineral supports are cut away. Formerly pillars of salt were left for this purpose, but they disintegrated so rapidly as to be dangerous, and the safer system was adopted of completely filling up the excavations with the waste salts and rock salt. Within the mines, potash salts are broken down by blasting as in ordinary mining. In man}- of the works, electricity is used for motor power and in lighting. The mines are necessarly kept perfectly dry, and visitors are free from the inconvenience and discomfort usual to under- ground workings. The carnallit blastings tear off large blocks which are broken up by the miners and transported in small cars to the shafts, thence to be hoisted to the sur- face and delivered to the chemical works for grinding and further treatment. MANUFACTURING THE CONCENTRATED SALTS* As has been intimated, at the mine-mouths are extensive and completely equipped chemical works which refine the crude salts and separate their constituents into products best suited to the various chemical industries. A most im- portant feature of the refining is the reduction in weight by rejecting useless constituents of the salts, thus securing the valuable potash in a small bulk; an essential consider- ation for the man who pays the freight or handles the products. Yet to refine closely is an expensive process, and much study and great care are necessary to balance properly the amount of concentration against the diverse uses and the cost of shipping and handling the various materials. In estimating the quantity of potash in the different products, chemists are accustomed to make use of the term *' actual potash," that is, oxide of potassium (K2O). The object of this is to establish a basis of com- parison of all potash salts; therefore, when ''potash" is named in potash products, it is understood that the word refers to the amount of actual potash present, and not the quantity of sulphate or muriate of potash, as the case may be. As a matter of fact, potash is not sold commonly in the form of "actual potash" (K2O), but as sulphate of MANUFACTURING THE CONCENTRATED SALTS. 29 potash, muriate of potash, sulphate of potash-magnesia, etc. Sulphate of potash is simply actual potash combined with sulphuric acid; and muriate of potash, actual potash combined with muriatic (hydrochloric) acid. In manufacturing muriate of potash from the crude minerals found in the Stassfurt mines, all lime, soda, mag- nesia and other salts are removed. Crude carnallit, as it comes from the mines, contains on an average 15 per cent, muriate of potash; the manufacturing process consists in separating this 15 per cent, from the 85 percent, of other crude ores, and makes use of the chemical knowledge that these other salts are either more soluble or less soluble in water and other solutions than pure muriate of potash. The coarsely ground carnallit is " charged " into a large dissolving vat containing a boiling, saturated solution of magnesium chloride (a by-product of the process, as shown later). The mixture is agitated thoroughly by means of a ' ' blow-up, " or live steam jet, an#4s boiled until it shows a degree of concentration equal to 32 degrees Beaume. The contents are then drawn off into settling tanks, from which the clear solution is run into crystallizing vats and left three or four days to cool and crystallize, the deposit containing about 60 per cent, pure muriate of potash. The liquors drawn from the crystallizing vats are boiled down (now almost exclusively in a vacuum apparatus, but formerly in open pans), during which process some chloride of sodium and sulphate of magnesium fall out. This second solution settles and runs into crystallizing vats where practically all 30 MANUFACTURING THE CONCENTRATED SALTS. the potash separated as crystals of pure artificial mineral carnallit (KCl, MgCb, 6H2O), which is treated precisely as was the crude carnallit and gives a nearly pure muriate of potassium in one crystallization. The crystallized muriate of potash thus produced is contaminated by chlorides of sodium and magnesium, through adhereing solutions, and these impurities are re- moved by a series of washings with water. The liquor from these washings of the crystals is saved and used on fresh batches of the mineral ore. The crystals of muriate of potash are dried, after washing, and are from 70 to 99 per cent. pure. (KCl). The last ''mother liquors," or solutions from the crystallizing vats, (from which all the potash has been separated) are used for the manufacture of bromine and chloride of magnesium. The muriate of potash (chloride of potassium) manu- factured at Stassfurt is of various grades and contains actual potash in the following proportions: PURE MURIATE OF POTASH. ACTUAL POTASH. 70 to 75 per cent. contains 46.7 per oent. Soto 85 " " '' 52.7 " '' 90 to 95 " " '' 57.9 " " 98 " " " 62.0 " " When sold for fertilizing purposes, it is on the basis of 80 per cent, pure muriate of potash, corresponding to 50.5 per cent, actual potash. The price is based on this average and is increased or decreased according to the percentage manuf'acturinG the coj^centrated salts. 31 above or below it of pure muriate contained, as shown by chemical analysis. Muriate of potash serves as a basis for the manufacture of many other potash salts, such as nitrates, chlorates, etc. There are many by-products in the manufacture of muriate of potash, notably magnesium chloride and sulphate of soda, which later, owing to its purity and freedom from acid salts, is largely used in the manufacture of the cheaper grades of glass. From the residuum of the first solution of carnallit, treated with cold water, kieserit (sulphate of magnesia) settles out in fine crystalline particles, and is moulded into blocks. I^arge quantities of bromine and iron bromide are obtained at the end of the process. Some of the Stassfurt factories also prepare calcined magnesia, hydrate of magnesia, calcium chloride, carbonate of potash, carbonate of potash-magnesia, etc. In order to obtain the complete extraction of potash, the processes of manufacture are complex, and solutions and salts require repeated handling. It naturally follows that the separation of commercially pure salts, from solutions of other salts, is an expensive process, and that it is only by the most painstaking care and full utilization of every pos- sible by-product, that potash salts can be produced and sold at the present low prices. Sulphate of Potash is manufactured in less quan- tities than muriate, owing to smaller demand for it in the market; but its consumption is rapidly increasing. There are several processes of manufacture. The one in general 32 MANUFACTURING THE CONCENTRATED SALTS. use is to concentrate a solution of kainit to a certain specific gravity, and then allow it to cool slowly in large crystal- lizing vats. The resulting crystals are washed and dried, and from the commercial salt sulphate of potash-magnesia, containing generally 40 per cent, of sulphate of potash, but when calcined 48 per cent. In the manufacture of sulphate of potash a solution of sulphate of potash-magnesia and a given quantity of muriate of potash are bQiled together, whereupon the less soluble sulphate of potash separates and falls as a precipitate, after which the solution is boiled down to a certain specific gravity, and cooled slowly in crystallizing vats, where the potash separates as crystals of sulphate of potash. As it is sold it varies from 90 to 96 per cent, pure, equivalent to 46 to 52 per cent, actual potash. The tables on page 35 give the average analyses of the more important Stassfurt potash salts. The figures show the pounds of various substances in 100 pounds of the dif- ferent salts. The numerous by-products obtained in refining the crude potash salts are utilized in many ways and for various purposes. Some of them contain 20 to 30 per cent, actual potash, but in most cases in such combination as not to pay for necessarily expensive extraction. Because of this com- paratively large content of potash, however, they are dried, calcined, pulverized, and mixed with crude salts, or other poorer forms of potash, to increase the potash content of these salts and give them added value for agricultural pur- poses. MANUFACTURING THE CONCENTRATED SALTS. 33 Besides the agricultural, soil-restoring, plant-feeding use of potash salts, large quantities are consumed by the chemi- cal industry in Germany, the United States and other countries, in the manufacture of carbonate of potash, caustic potash, nitrate of potash, chlorate of potash, chromate and bichromate of potash, alum, cyanide of potash, bromide of potash, permanganate of potash, yellow prussiate, and other compounds. The many sided technical and industrial activity of the age, in almost every trade, must have potash in one form or another. Doctors, photo- graphers, painters, dyers, cleaners, bleachers, weavers, soap- makers and electricians use it, while the modern rapid, cheap production of artificial cold, of preservatives, fire- works, gunpowder, matches, paper, glass and aniline dyes, and the extraction of gold from its ores are impossible without it. While applications are thus without number, it is of greatest importance in agriculture in supplying plant food. 34 MANUFACTURING THE CONCENTRATED SALTS. Crude Salts (Natural Products.) Actual Potash (KjO) Minimum Guarantee (KgO) . . . Sulphate ot Potash (K2SO4) . . . Muriate of Potash (KCl) Sulphate of Magnesia (MgS04). Chloride of Magnesia (MgClg). Chloride of Sodium (NaCl) Sulphate of Lime (CaS04) Insoluble Substances Water KAINIT. CARNALLIT. SYLVINIT, 12, 12, 21. 2. 14. 12. 34. ]. 0. 12, 9.8% 9.0% 12. w 21.5^ 22.4^ 19^ 0.5% 26.1% 11.4% 12 A% 1.5% 26. -6% 2.A% 2.6% 56.7^ 2.S% S.2% Sulphates (nearly free of Chlorides.) Actual Potash (K2O) Minimum Guarantee (K„0) . . Sulphate of Potash (K^SO^) . . Muriate of Potash (KCl) Sulphate of Magnesia (MgS04 Chloride of Magnesia (MgCla) Chloride of Sodium (NaCl) Sulphate of Lime (CaS04) Insoluble Substances Water SULPHATE OF POTASH. (90^) 49 9^ 48.6^ 90.6^ 1.6,^ 2.7% 1.0$? 1.2% 0.4j? 0.3^ 2.2^ 52.7^ 51.8f» 97.25S 0.35^ 0.7^ 0.4^ 0.2^ o.d% 0.2^ 0.7^ SULPHATE OF POTASH- MAGNESIA. 27.2^ 25.9^ 50.4^ 34.0^ '2.'5^ 0.9% 0.6^ 11.6^ Salts Containing Chlorides. Actual Potash Minimum Guarantee. . Sulphaie of Potash Muriate of Potash Sulphate of Magnesia. Chloride of Magnesia. Chloride of Sodium. . . Sulphate of L)me Insoluble Substances.. Water MURIATE OF POTASH. 57 9% 56.8^ 91.7^ 0.2^ 0.2% 1.1% 0.2^ 0.6^ 52 7% 50.5^ 83.5^ 0.4^ 0.3^ 14.5,^ 2% 1.1% ro/75^ 46.7^ 44.1% 1 7% 72.5^ 8% 0.6^ 21.2^ 2% 0.5% 2.5^ POTASH MANURE SALTS. MIN. 20,'? MIN 21.0^ 20.0$? 2.0^ 31 6% 10 6% 5.S% 40.2% 2.1% 4.0,'? 4.2% 30.6^ 30.0^ 1.2,'^ 47.6,% 9.4% 4.8/f 26.2?i 2.2^ 3 5% 5.1^ < H O fu Q Pi U C5 z Q Z S o erf O 'A COMMERCIAL STATEMENT* For fifty years the world's demand for potash has grown rapidly until to-day it is over five million tons per year, and the Stassfurt industry alone enables this demand to be satisfied. Previous to the discovery of the Stassfurt deposits, potash, as used in the arts, was derived chiefly, as its name implies, from the leaching of wood ashes. The supply to be had from wood ashes and condensed hull ashes is lim- ited. About 2,000 tons of muriate of potash are annually made in the south of France, by evaporating sea-water, and the Scottish manufacture of iodine from kelp yields perhaps 1,000 to 1,200 tons yearly of muriate and sulphate, as by- products. There are few other minor sources of supply, such as nitrate of potash from India, wool-washing residues (suint potash), and potash from beet sugar residues. In 1884 the various mines producing potash were com- bined under a central office. The organization now in- cludes forty-five mines: This combination has about 270 executive officers, in- cluding representatives in foreign countries, while the mines themselves employ in round numbers, 1,300 officers and 30,000 laborers, and use 800 boilers and 900 steam engines with 75,000 horse power. Kach of the works has its own railroad track, connecting with the main line, and, in some cases, this reaches a length of about 73>^ miles, and most of the works have their own locomotives and railroad cars. The daily output varies, but in the best seasons of the year, which are the spring and fall, it reaches as high as 2,300 carloads of ten tons each. The following table gives the production of crude salts, from the commence- ment of mining to the close of 1906. COMMERCIAL STATEMENT. 41 Production of Crude Salts. (Metric Tons of 2,204 lbs.) KAINIT ROCK YEAR CARNALLIT. KIESERIT. SYLV [NIT. AND HARTSALZ. TOTAL. 1861 2,293 2,293 1863 19,727 ■"26 . . . .... 19.747 1863 58,304 68 58.372 1864 115.409 89 115.498 1865 87,671 75 '. '. '. I'M'i 89,060 1866 135,554 414 5,808 141,776 1867 141,604 1,144 8,974 151,722 1868 167,337 1,418 10,772 179,527 1869 211,884 227 16,857 228,968 1870 268,226 71 20,301 288,598 1871 335,945 47 36,582 372,574 1872 468,538 23 18,067 486,628 1873 441,079 8 6,101 447,188 1874 414,961 16 9,753 424,730 1875 498,737 5 24,124 522,866 1876 563.669 145 17,938 581,752 1877 771.819 152 35,477 807,448 1878 735,750 520 34,004 770,274 1879 610,427 761 50,207 661,395 1880 528,2i2 893 139,491 668,596 1881 744,726 2,082 158,330 905,138 1882 1,059,300 4,658 148,477 1,212,435 1883 950,203 11,791 228,817 1,190,811 1884 739,959 12,389 217,107 969,455 1885 644,710 11,970 272,370 929.050 1886 698,229 13,918 247,327 959,474 . 1887 840 207 14,186 237,629 1,092,022 1888 849,603 10.754 2, 220 ^ ' 375,574 1,238,151 1889 798,721 9,354 28, 329 362,611 1,199,015 1890 838,526 6,951 31 917 401,871 1,279.265 1891 818,862 5,816 32, 661 512.494 1,369.833 1892 736,751 5,783 32, 669. 585,775 1 360,978 1893 794,660 4,807 49, 140 689,994 1,538,601 1894 851,339 3,865 63, 495 729,301 1,648,000 1895 782,944 3,012 76, 097 669,532 1,531 585 1896 856,223 2,841 90. 390 883,025 1.782,479 1897 851,272 2,619 84, 105 1,012,186 1.950,182 1898 990,998 2,444 94, 270 1,120,616 2.208,328 1899 1,317,948 2,066 100, 653 1,063,195 2,483,862 1900 1,697,803 2,047 147, 791 1,189,394 3 037,035 1901 1,860,189 2,335 190. 034 1,432,136 3,484,694 1902 1,705,665 1,821 188, 821 1,354,528 3.250,835 1903 1,844,037 1,553 196, 140 1,582,867 3,624,598 1904 1,911,166 1,056 234, 455 1,906,823 4.053,500 1905 2,239,710 2,731 230, 622 2 405,536 4,878,598 1906 2,263,197 9,191 284, 944 2,754,572 5,311,903 42 COMMERCIAL STATEMENT. These salts were either sold directly from the mines, for agricultural purposes, or manufactured into more con- centrated potash products for use in agriculture, or in the arts and other manufactures. The table on page 43 shows the use made of the various salts, from 1880 to the close of 1906. The greater part of the crude salts, manufactured into concentrated products, was converted into muriate of potash. The following table gives, in metric tons of 2,204 pounds each, full detailed data as to the various con- centrated salts produced from 1884 to the close of 1906. Production of Concentrated Potash Salts. (Metric Tons of 2,204 lbs.) SULPHATE OF Q . MURIATE SULPHATE POTASH -MAGNESIA. h 5 C5 !^ '^ td OF OF POTASH KIESERIT rt Q z YEAR. POTASH POTASH CRYST- CAL- MANURE IN w 5 S X ?: tj 80 PER 90 PER ALLIZED CINED SALT. BLOCKS. W D J ■"* O -< CENT. CENT. 40 PER CENT. 48 PER CENT. V i-; ^ - K u O 1884 106,380 3 000 400 8.000 9,500 17,800 1885 104, .-00 4,000 450 9,000 8,400 18,500 1886 110,200 3,639 475 10 111 8.161 19,500 188T 130,000 10.528 500 6,285 8,163 24.018 1888 132,000 10,916 52 ■^ 11,380 13,918 28,325 1889 131,593 7,321 671 9,215 17,285 31,824 1890 134,760 13.839 907 10,830 17.620 32,005 1891 143,488 18,981 1,053 11,400 16,045 28.559 1892 121.028 15.466 708 11,84-i 16,895 23.855 "'ii 1893 132,529 16,361 739 12,643 17.344 24,386 105 1894 147,936 15,243 1,780 12,718 19,728 26.440 216 189.5 145,027 13.403 898 8 249 19,724 25,115 142 189(5 155,805 13,889 1.051 4,622 19,253 24,987 211 1897 158,863 15,403 922 7,415 23,042 25.669 214 1898 174.380 17,781 914 10,535 24,284 19,934 728 1899 180.672 24.656 579 8,4.=)9 70,916 28.216 260 1900 206,471 31,2?>5 933 12.150 129,863 28,.^08 358 1901 211,421 28,196 936 11,750 147 170 26.727 361 1902 191,039 30,202 600 16,834 139,32t) 26,809 767 1903 1 206,347 34,807 778 22.296 161,786 23,509 548 1904 235,298 39.447 775 27,672 196,860 26,471 463 1905 254,711 42,420 718 30.589 215 408 35,003 600 1906 1 279,320 51,198 834 37,110 278.3^5 29,411 632 COMME^RCIAL STATEMENT . 43 en O a •o 3 u O -a CO ^J ■i-iO!:-!>?>OOC3'+'0!>co-T-^<»OJCiO'i2'Xiooc:aoaoco:o as CO t- >- o 1- c- o-j 05 -* cx; in -* CO oi CO •— ct GC' -f QC I- -f o 1- o — ^CO-*QOi-(a«CO«5c-GiL-^-i-;TP r-^ t- O rt^C^GO CO i-^_^i-h CO OjTJi— lO. oTccodooL- cTt-^t-c-^oco inodcR of lo'co'ffi-f CO r-'oico'oj -^'o'c: C0»n^3^!-i-H£-'rtHC0t-35CO--t<-rHCO-C5Tt'002!>C3T-(0?5C050i!>-r-ilOGOir333»COO?^lCt-QOi-l'*0? • -COOt-OQO^^OOQOt-Ttit-OOTt't-OJ'XiO'^mcOt-aOOOii- 05Tf '^ 0-i Gv «o ic o o«_T-H i-<_a5^io_c:^co_^o«^L^o i-,,^, ^^-v •' "— i--^. — r''^,^ CO of in co'ct'co^io'cTc:? co" co'co i-h"^''o'o''ic lo -t-'-t"io'-t th ^' -£©* of OT-ioiioO'*OQOTtT-i(Ms>coaoooiTtHOicoT2 5>S'252^S^j:? TH 1-1 1-1 tH T-H T-l T-l T-( T-IT-I i-lT-l Cejt-H-'-iTH— '00cot-gmi>Tt':0 ITS 01_10_ eo"o~o odod oio T^ iri oodo o cctt ?c ^^oo <^f ^^T)H~qi -^'qo'oj t£^ oiO«co'Tj<'*iocooD=:ict^-*;oo45oeoio<50o3 ^5 p; o^ oj_o oq -*_o cc m -* »c oj rr co. _ ' ■^ ?? o ■?* th :o ^^_.. ^_^ ^^^ ^ I ,.^^^ wM /-^ »f^ J^ "^ > /V^ ^/^ f~^ T^ ;0 t!T^ -rf 1—1 iC T— I GO 05 03 CO IX! ■ oi" CO CO T-H o?~«o of ■*' o>TfcocoiomT-iiocDOTroj'*c5iOQOi5inOT2jq;cgw)3;r^^«.-- »ot-oo5i-«it-ooco(X)ooQOc-t-^cx;!-~Gocoroco co Qq_i> Qq_05.oj_o* ^ 1-i i— I T— I T-i ri 1— I (Ji C* 2« S w D < . ca h K 2 o u f- t-; £ < z 'J S w < D U <" Z 2 < O 5; o Q050050-fi0500->-"0!>Ort_Tr C3_'* o co_in th rf'cs'co-TtH'eo L^ os'cf odcj'o'urrin ofo th 00 oic o't-; t-c o ri p k; cjcoiOTfeococoo^o^corHooococococsoiOQin'jt-ococot-o 10t-O05C-C0C0Q0Q0l-Q0t--C0I— i~i^-!.--l--05W CO i- CO t-^OD^i-^C^^ COTJ<<;^Oli— lOaOJCOCOCOOilO •Q0i-mi03CT-IMCD»0X>—OG0C0!>mC0O •00C0m03^i-i3DOi— i-iCOQCCOOS-^ Q0 4>_ th^ T-Tco ^co'co'io c-'^o^'c-^t-^co •^of of !>030"^-*aoo3C*50coTt-^eoQO-i-i'*eo?:-05(Ni>e«otr"* eOOrfleOlOQOO^SSt-^t-OSCDCOOSOi-^-^OSl-GOCOC^OSQOCt- tH 05_(N ^ CO Ol_C-^Q0 t^J>_10 OO CO -^T Oq_lO_in IC !> CO__'*_XI_T-1^0^CO^'-I^ i-^ -jTco^o't-^QcTarof o --'~^-^■^ orrin oTo^o^co' of o 00 >f^'^-'o^co"lo'o?^lO T-ii-ir-n-KMcocoe'^roco-'^ifflcoioinmcoicinE-aot-t-coco OT-l03eO'*if5COt-OOOJO — 0«CO-^mcDi>G0050T-i(y!CO-Tt' i i i i S 1 1 1 1 L '■ X" — f"^ ' 1 i ' L 1 I ' I 1 1 1 1 i 1 i 1 i I 1 : 1 I.I 1 1 iJ 1 1_IJ 1 H 1 1 ! 1 1 1 ! , 1 1 1 _..! ! ! 1 ! 1 J 180,000 tons. 1889 l90 '91 '92 '93 '94 '95 '96 '97 '98 '99 1900, '01 '02 03 '04 '05 1906 COMMKRCIAI. STATEMENT. 47 O X '^ O 2 s •4-t 3 C/3 rt (J 1> C-, b b Hi C 3 ^ (U ^ O r* S r-i c« -fj Vi £ ;^ o t« o ^ c« a +J r« O c a. •»M -M •^ o 7J O 6 s i/5 3 S o O 1ft 05 tLJ c^ in tH (^^ ^ ^ j^ ^ C5 Ifi CO X Tt< CO c: l- X to QC' '^ i- lO O ?2^g^q Tl< to ^ tH tH CO Tj( CO L- to to '-t^ Oi_^ CO -Tf -+ X to- 10 X in th CO Tt< Oi TT to Cl X o« QC cr. lo' X in o« to TH a? 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Tf CO QO 05' to' C? ■* L- CO^ T-^ T-T to" T-T -TH "^ X Tt* Tf CO TH -t ■?> _ to c ~~^ Oi to tc 05 L- tH T- CD TH Tf .QO to C5 S I- 03 i- c: oi m Tf tH !> CO TH in to ot_ X m' X L- to -* £- tH CO X QO 10 0" o-i 0^ ift -+ tH m th S> T}< ___j,^__ ' L- TH OJ CO X in CO th t- c: X TH Ci CO T- in 1^ X Tt* CO CO T- CO in to tc tc to to CO X Jt CK X Ct_ X__ lO X X ■<# CO X T- 00 Ct CO (m' of IQ ^ tH in T-T T-i in CO > '/■ 1 1 « _w f- U5 *u< z u r 'w ct cc = s > rt U 3 = a ^ r ■a fe B d ^ o C/5 # eo o« -* c o CO i# O Tt in Tt X X X rH CO C3 CO ■^ o CD lO 0? ec O t- CO ■* 00 0? o eo o t- cc fN CO O -r^ 03 in t- 03 in Tt< T-H lO -* CO cc in CO in CO eo »n Tt t^ 1-1 CO eo rH rH o OS (?? tJ< O «b (M OS •* 00 ■># QO t- inmiooosoooo 00 Tl CO CO lO CO eo o o oj !> 00 1- 03 Tj< CO S> CO O 1 rH £- lO t- o 0? 00 OS in CO m T-l X O O 03 1 Tf< c« 03 Tt CI O (?« iT. s> cc t- in X s> o: OS i>- CO in l-H in rH cc 03 y- -1* or c- IC »o Tt (M OJ rH CO co rH ■^ 03 03 03 CO X OS -^ IC (^ <- CC ■rl o. l.T 1- 0. X X OS CO (N Tf OJ o» M ^ CO CO ir. -* r^ o £> CO O- CC rH -^ )> cc CC IT CO -^ X OS 00 ■rt 00 CO .^ y- CO o- OS ;c .p_ cc t-^ Tl< Os' 1 1-1 Tl CO >r f- CO 00 o; r- 0^ 00 CO 00 CO 1 CO c. o? 03 ■rH O OS Tt OS (N c c OS .^_ CQ in 03 in X Tfl ^ ■r-^ X OS Tt OS OS OS OJ ?-- Tt* t- a- o rH r^ ic 1-^ c- i- OS t- o 1-1 -!; CO o rs» c^; D CO CO 1^ 00 ""i* 1 CO Tfl 0? 03 1 OS CO «o CO lO -* Tf< O 00 1- in OS T-l r- X X in t- rH CO 00 ^ O (N OJ CJ ^ ^ ^ c o cc ■rH OS O OS ■* OS O 1 OS CO t- 1-1 03 JO O 04 -i-i Tt< o Tf in CO ffl« 03 1 OS O i- S3 i^- oc CO IT c J> 00 -* ec T-{ j> o- C3 03 rH ■rH Ttl CO CO OS ^ o: (M CO £- ec 1-1 »no!>^ocD^-coo 1 t- (M ^ ss. (jj ta 1- c ^ t- CO -"^i Tt< c« ■i-i Oi T-l rH T-t 2^ 00 (M IC eo Of. Tti 00 oc o- OJ rH Tt t- in CC 03 CC r- CO ^ r- r- ?- O !> 1- c- c ^- ic c Tt 03 ifi O" 00 in 1 Ti 0^ ^ (> lO co o- eo Ti Tt< Oi OJ ■^ >c in o- 00 GL o- a-. o< C cc w w o 1- '^ 1^ OS in t- c CO CC ^ CO CT OS ■^ <- IM or m ^ c cc o in in CO t- (^1 CO 4-- ^ o- CO i- o: CO CO 1 CN T— I in o (^ CO oc o: 1- (^< CO OS CO rH o in ^ OS OS 03 j> in CO 00 .^ 1-1 c co t- CO r- ?^ c lO CO O rH O CO CO ?> CO" 1 OS (X c^ CO T- CO 00 1-1 CO ■* rH CO 03 1 1— 1 -r- IC cc lO (N O cc co cc CO CO CC Tf o eo £- cc If: CO t- 03 in 00 (N GO CO T- co CO E- O CO c CO ec c: 1-1 OS C> OS '^ 1 lO T-( CO T- CO t- r- eo 03 1^ 03 rH 1 T-l 1 (B = I- -a OS 1-1 CO OS 1-1 OS eo OS 05 cc T-l 03 -!+i t- OS OS in OS t- 1 « « OS -^ O I- CO o ri T' oc c OS 03 O CO OS O t^ IT t^ c« 1 -Q CO ^ — in — CO CO IT ir. o- lO o X -^ CC T- CO 03 1 13 O 00 — 00 1-1 -^ in rH in 1-1 eo t/5 >■ K H D O > c E I. 4 4J Id c ct c c c C c a: > b c pi > 1? a -1 c 'rt C CT b. r > c _ u g C 13 C n C ) P p: tr Ct W 1 ►i: <; s ht: a P- (A z p fe Relative Consumption of Actual Potash in Fertilizers in Different Countries. (Shown on basis of pounds per 100 acres arable land.) Germany United States Belgium Holland France England Scotland Poland _ Spain — Sweden - Norway - Denmark THE IMPORTANCE OF POTASH IN AGRICULTURE. What has been already broadly stated merits closer and detailed observation and study. Crop after crop taken from the same soil, gradually, but nevertheless surely, exhausts it. The yields diminish from year to year, until a point is reached where once rich and paying lands are tilled at a loss or abandoned to weeds. Mark the contrast in twenty years of gradually shrinking yields in all directions. A single example will suffice here. In 1870 the average potato yield was 86.6 bushels per acre; in 1890 it was but 55.8 bushels. This gradually but surely diminishing pro- ductiveness is not confined to one country, but prevails universally wherever manure or fertilizers are not employed to replace what is removed by crops . This failing, commonly called " wearing out " of the soil, is now known to be due to exhausting its ' ' plant food, ' ' which is the usual term used in speaking of the chemical substances necessary to plant growth. The three essential plant food ingredients are phosphoric acid, nitrogen and potash; and everyone depend- ent upon the soil for a living needs to become thoroughly familiar with them, and their sources of supply and relative values. Commercial fertilizers derive their values from the percentage of these three essential ingredients which they contain. This word "essential" is deliberately and ac- THE IMPORTANCE OF POTASH IN AGRICULTURE. 51 cTirately used in speaking of all three of these, which fact must not be forgotten in noting how much space is given, in this work, to the necessity for potash. The chief effect of potash in plant life and activity appears to be in the forma- tion of starch and the development of the woody part in stems and stalks, and the pulp and sugar in fruit. The amount required for the proper and best development of a crop de- pends upon the nature and weight of that crop. Different growing plants have different appetites and necessities for potash and the amount of it which they have taken away from the soil can be accurately ascertained by chemical analyses. The following table shows the number of pounds per acre removed by an average yield of: Grain and Hay in rotation, 75 lbs. potash. Oats, 62 '' Potatoes, • 74 " Sugar Beets, . • .143 " Meadow Hay, . . 85 - Green Corn, . . I64, " Tobacco, 103 " A common four-year rotation of crops in the northern states is corn, wheat, clover, timothy. By it the amount of potash taken from each acre is: Corn, yielding 52 bushels, 82 lbs. Potash. Wheat, " 25 '' 22 " Clover, " 2}i tons, 120 " Timothy, '' 2 " 94 " Total— 318 lbs. Potash. 52 THE IMPORTANCE OF POTASH IN AGRICULTURE. This loss of 318 lbs. of actual potash means an average of 80 pounds each year, or an equivalent of 160 pounds of muriate of potash. This must be replaced in the form of manure or fertilizer, or poverty of soil rapidly follows. Where the fodder is fed to cattle, and the manure re- turned to the soil, part of the potash contained in the crop is returned to the soil. If, on a farm of 100 cultivated acres, one third of the required potash be thus returned (con- siderably more than usually is saved in ordinary farming), there still is 5,000 pounds of it annually removed from the farm, which must be replaced by some form of potash fertilizer, otherwise the original condition and richness of the soil cannot be maintained. More or less potash is naturally present in all soils, but, for the most part, in an insoluble and unavailable form, excepting that very small part which is freed and made accessible by the action of the elements. Even this original natural supply is very lim- ited, and were it all at once to be rendered soluble, it would quickly be leached out by rains and so completely lost. In the beginning of vegetation easily soluble potash is absolutely essential, but it is not generally present in such form even in soils which contain a fair supply of it. The importance of potash salts in agriculture, therefore, is evi- dent: farmers must use them to make good the losses due to the growing and selling of crops. In this connection it is worthy of especial note that a part of the fertilizing sub- stances contained in barnyard manure is insoluble, and so unavailable, — useless as plant food. This has been practi- THE IMPORTANCE OF POTASH IN AGRICULTURE. 53 cally demonstrated by long, careful tests made at the Ex- periment Station at Rothamsted, England. For 42 years a section of land was treated with farmyard manure at the rate of 14 tons per year; during the same period an equal section, of the same character, received chemical manures. The actual plant food applied per acre each year in each case, and the average yield of wheat was: IN FARMYARD MANURE. IN CHEMICALS. Nitrogen, 200 lbs. no lbs. Potash, 160 lbs. 100 lbs. Phosphoric Acid, no lbs. 87 lbs. Yield of grain, 32.25 bushels. 39.75 bushels. The plant food in the farmyard manure, though applied in great excess, as compared with the chemical manures, failed to give as good results. This was undoubtedly be- cause a large part of the potash and phosphates in the farm- yard manure was unavailable, and could not be fed upon by the growing plants. ~ - Scientists and practical farmers agree that the by-pro- ducts of the farm (farmyard manure) returned to the soil, are not sufficient to keep it fertile, and the loss by cropping must be made good by applying chemicals : — nitrogen, in the form of nitrate of soda, sulphate of ammonia, tankage, fish scraps, etc., or by growing cow peas, clovers and other legumes, which absorb nitrogen from the air. The main source of the potash supply is the Stassfurt potash salts, while mineral phosphates and bone products are depended on for phosphoric acid. Chemical manures have an advan- 54 THE IMPORTANCE OF POTASH IN AGRICULTURE. tage over those of the farmyard, in that they are readily available, cheaper and more agreeable to handle, besides being free from weed seeds and disease germs, which some- times occur in the farm products. In 1900 the United States consumed a total of about 2,600,000 tons of fertilizers, having an average composition of 2 per cent, ammonia, 3 per cent, actual potash and 9 per cent, available phosphoric acid. Thus, the consumption of the three necessary elements of plant food, — potash, nitro- gen and phosphoric acid was : Nitrogen, 52,000 tons. Potash, 78,000 " Phosphoric Acid, 234,000 " To show the number of pounds of potash taken from the soil for each 100 pounds of phosphoric acid, a table of the leading crops is here given. 100 pounds of phosphoric acid is taken as the basis, and the comparison shows the prob- able exhaustion of potash in the soil. CROPS. PHOSPHORIC ACID. POTASH. Wheat, .TOO lbs. 246 lbs Corn, 100 " 173 " Timothy, 100 " 378 '' Clover, 100 " 456 " Barley, 100 " 335 " Potatoes, 100 " 219 " Tobacco, 100 " 475 " Cotton, 100 " 325 " Oats, 100 " 250 " Average, 100 lbs. 318 lbs. THE IMPORTANCE OF POTASH IN AGRICULTURE. 55 For every loo pounds of phosphoric acid taken from the soil, the average is 318 pounds of potash. According to this, instead of using only 125,000 tons of actual potash, the farmers of the United States should have used about 744,120 tons, — in order to replace that which was taken from the soil by the growing crops in a single year. The plant food represented in the above figures is based on actual fertilizer consumption: — the 234,000 tons of phos- phoric acid were undoubtedly needed, and the 744,120 tons of potash just as much so. ARTICHOKES, WITHOUT FERTILIZER. ARTICHOKES, FERTILIZED WITH POTASH, PHOSPHORIC ACID AND NITROGEN, EXPERIMENTS MADE AT SOUTHERN PINES, N. C. SWEET POTATOES FERTILIZED WITH PHOSPHORIC ACID AND NITROGEN. YIELD PER ACRE: I22k BUSHELS. SWEET POTATOES. FERTILIZED WITH POTASH, PHOSPHORIC ACID AND NITROGEN. YIELD PER ACRE: 25© BUSHELS. EXPERIMENTS MADE AT SOUTHERN PINES, N. C. POTASH SALTS FOR FERTILIZING. The most important of the potash salts used and in demand for agricultural purposes, with their percentages of actual potash, are : PER CENT. POUNDS ACTUAL POTASH ACTUAL POTASH. PER TON OF 2,000 LBS. Muriate of Potash, 50 i ,000 Sulphate of Potash, 50 to 55 1,000 to 1,100 Sulphate of Potash-Magnesia, 27 to 30 540 to 600 Kainit, 12^^ 250 Manure Salt, min. 20^, 20 to 21 400 to 420 The practical farmer is frequently confronted with the question: " Which of these potash salts shall I use, and how must I apply to get the best results?" the following explanations and suggestions help him to answer. Muriate of Potash is the cheapest source of potash particularly in sections remote from the sea ports. This is because it is a concentrated article. One half of its weight is pure potash, and it relatively costs much less in trans- portation than those products containing greater bulk and weight, but a lower percentage of potash. Muriate is the principal source of potash employed in commercial fertili- zers and is well suited for most agricultural crops. It con- tains considerable chlorine (46 per cent.) w^hich substance is considered injurious to the quality of smoking tobacco, for which crop sulphate of potash, although higher in price, should always be used. Many farmers likewise use sulphate in preference to the muriate on oranges, sugar cane, potatoes, fruits and tender vegetables, believing that the better quality produced compensates for the greater cost. POTASH SALTS FOR FERTILIZING. 6 1 However, deleterious effects on quality of the product can usually be avoided by applying the muriate of potash several months preceding the planting of the crop. By this previous application, the injurious chlorine contained in the muriate of potash is washed down by the rains into the subsoil, while the valuable constituent, potash, remains fixed in the surface-soil until it can be made use of by the growing plants. When muriate of potash is used regu- larly as a source of potash, it is desirable that the land receive a dressing of lime about once in five years. This will heighten the effect to the muriate. Sulphate of Potash, and Sulphate of Potash=Magnesia. These potash salts, especially the first mentioned, are the safest potash fertilizers to use under all conditions. The sulphate is always preferred to tobacco growing, also for oranges, sugar cane and tender vegetables. It deserves preference on soils inclined to be sour, and can be used in large quantities, for years in succession, without necessitat- ing the use of heavy applications of lime, which are needed when muriate or kainit is extensively used. Sulphate of potash is the most expensive source of potash, and for this reason is not as universally used as the muriate of potash. Manure Salt is another source of potash, of which it contains 20 per cent. It is similar in its effect to kainit and may be used instead, but neither one is recommended for tobacco, oranges, or in any case where there would be objection to muriate; in all such cases sulphate of potash should be taken. 62 POTASH SALTS FOR FERTILIZING. Kainit, as previously explained, is a raw product and contains only one-fourth as much actual potash as the muriate of potash. It is much cheaper per ton, though the potash in it costs more pound for pound than in the muriate, because of the freight, which has to be paid on the whole mass regardless of the potash contained in it. It is frequently preferred to the muriate on account of its marked effect in ridding the soil of injurious insects, (cut worms, w^hite grubs, onion maggots, etc.^. It is also highly esteemed in the cotton-producing states as a valuable pre- ventive or remedy in ' ' cotton blight. ' ' Mangel wurzel and other cattle beets and asparagus are particularly benefited by kainit. It is most effective as a preserver of stable manure, and many practical farmers, though knowing that muriate of potash is cheaper, still prefer the kainit, because it is less concentrated, and requires less caution in mixing with other fertilizers and making composts. In sections remote from the sea ports it may be so expensive (because of freight) as to make muriate of potash decidedly more economical. General experience has taught that on light soils its effects are ver}^ beneficial, but on heavy ones muriate of potash is to be preferred. The following table is arranged in two groups to dis- tinguished between those which contain chlorides and those which do not : CONTAINING CHLORIDES. FREE OF CHLORIDES. Muriate of Potash. Sulphate of Potash. Kainit. .Sulphate of Potash-Magnesia. - Manure Salt. POTASH SALTS FOR FERTILIZING. 63 Those in the first group can be used with safety upon most agricultural crops, whereas those of the second should have preference for tobacco, oranges, or wherever special quality of fruit is essential, and wherever the more valuable result or return will justify the use of the higher priced fertilizer. As previously explained, potash is only one of the three essential plant food ingredients ; the others are phosphoric acid and nitrogen, and all three are of equal importance in plant life. To rnake potash fully effective as a fertilizer, it is necessary to use it jointly with phosphoric acid and nitrogen, each in proper proportion . No one of these three ingredients can take the place of another in plant feeding, nor can an ex- cess of any one compensate for a deficiency of a second. Potash salts should not be used alone, except in rare cases when soils are so rich in phosphoric acid and nitrogen, as compared with potash, that the latter alone is needed. In most cases, however, in order to produce the best effects, it is necessary to use potash salts jointly with material supply- ing phosphoric acid (acid phosphate, etc.) and nitrogen (nitrate of soda, fish and meat refuse, cottonseed meal and others). A mixture of these three ingredients is called a " complete fertilizer, " and complete fertilizers, as sold in the market, contain potash, phosphoric acid and nitrogen in different proportions to meet the demands of the various crops. Bach farmer, therefore, must be governed by his particular needs in buying fertilizers. The value of the fer- tilizer, as already pointed out, depends entirely on the 64 POTASH SALTS FOR FERTILIZING. amount of potash, phosphoric acid and nitrogen it contains. If potash is bought separately, then the other two necessary plant food ingredients must be supplied also, or else that which is supplied may be a practical waste and all crops fail. In the rational use of fertilizers, close attention must be given to the nature of the soil upon which they are to be used, since soils differ even from one season to another, depending on the preceeding crops grown and what they have removed from the soil as well as on its original formation and composition . All this must be made a careful study on the part of the farmer if he 'wishes to apply fertilizers to the best advantage and greatest profit. In conclusion every farmer is advised to study the work of the Experiment Stations in the different States, as they have been established for the purpose of carrying on practical field trials to find out which combinations of plant food are best suited to the various soils and crops. The results are of value and importance to all those who earn their living by tilling the soil. Time, money and labor can be saved in this way, but the real progressive farmer will not only keep himself informed about the experience of others, but will also, to a certain extent, experiment on his own account, to learn which methods of cultivation, rotation and fertilization can be practiced with the greatest benefit and profit to himself. But whatever his conditions, potash — the producer of starch, sugar and strength of fiber — must not be allowed to run down in the soils which grow his crops. 1^ UNZ * CO., PRINTIRS, 84 »R«ABWAY, NBW Y'