application by eastern truckers. If a complete fertilizer is desired for these crops the one recommended for tobacco would be about right.

CELERY AND ONIONS.

Celery and Onions are largely grown on the black muck soils of the State and a fertilizer for them should be high in potash. The basic formula for tobacco meets the situation pretty well-even more potash would do no harm. Frequent applications of 100 pounds to the acre of nitrate of soda during the growing season is said to work wonders with both of these crops. It pays to use fertilizers liberally on both.

STRAWBERRIES.

Strawberries should be liberally supplied with phosphoric acid and potash in addition to that in the manure used in preparing the ground. An application of 150 pounds of nitrate of soda to the acre when the berries are beginning to set is said materially to increase the size of the fruit.

THE HOME-MIXING OF FERTILIZERS.

BY CHAS. E. THORNE,

Director Ohio Experiment Station.

We use commercial fertilizers in order to feed our crops on three chemical elements and three only, namely: nitrogen, phosphorus and potassium. It is true that several other elements are equally essential to the growth of the plant, but these are furnished by the soil in sufficient quantity without our aid. It is also true that some soils must be limed before they will yield remunerative crops, and it is further true that lime is an essential plant food; but we apply lime chiefly as a soil corrective and not primarily as a plant food, as we do the three elements first mentioned. In other words, lime will be required as a soil corrective before it is needed as a plant food, and when we use it for the first mentioned purpose it will also serve the second.

FERTILIZING MATERIALS.

While there are numerous commercial materials that may be used in fertilizing the soil there are three or four which are so easily obtained and also so effective, that the Ohio farmer has at present no occasion to look for anything else. These are nitrate of soda, muriate of potash, acid phosphate and steamed bonemeal.

NITRATE OF SODA.

Nitrate of soda is a coarse, grayish salt, imported from Chile, South America, and hence is sometimes called Chile saltpeter. It should contain about 151⁄2 per cent nitrogen, and is the most effective carrier of nitrogen in use for fertilizing purposes. The usual cost, including freight, is about 234 to 3 cents per pound in small lots by the time it reaches the Ohio farmer, but when bought by the carload this cost may be much reduced. Like common salt it absorbes moisture from the atmosphere and becomes lumpy, so that it is necessary to sift it and break the lumps when preparing to use it. A common sand sieve, such as masons. use, with quarter-inch meshes, will separate the lumps, which may be broken up with the back of a shovel or a wooden pestle and sifted again. The lumps constitute but a small proportion of the entire bulk.

MURIATE OF POTASH.

Muriate of potash is also a coarse salt, resembling nitrate of soda so closely that it requires considerable experience to distinguish them. The sacks, or bins, therefore, in which these materials are stored, should be kept carefully labelled. The world's supply of muriate of potash now comes almost wholly from mines near Stassfurt, Germany, from whence it is shipped to this country, usually in sealed sacks containing 224 pounds. It should analyze 50 per cent actual potash. Muriate of potash is the commercial name for this material, but its correct name is potassium chloride, since it is a combination of the elements potassium and chlorine (common salt is chemically sodium chloride).

Potash is a combination of the elements potassium and oxygen, containing about 83 per cent. of the former and 17 per cent. of the latter, and having the chemical symbol K.0, which is sometimes found on the fertilizer sack.

ACID PHOSPHATE.

Acid phosphate is an American product, being derived from phosphate rocks found in South Carolina, Florida and Tennessee, which are quarried, dried and ground into a fine powder which is then mixed with approximately an equal weight of sulphuric acid, the object of this treatment being to convert the phosphorus of the rock into a soluble form. When thus treated an acid phosphate should contain from 14. to 18 per cent available "phosphoric acid" or 6 to 7 per cent phosphorus; phosphoric acid, like muriate of potash, being a trade name. As it is the nitrogen for which we buy nitrate of soda, and the potassium for which we buy muriate of potash, so it is the phosphorus for which we buy acid phosphate. The phosphoric acid of the fertilizer sack is a

compound consisting of about 44 per cent. phosphorus and 56 per cent oxygen, hence an acid phosphate analyzing 14 per cent. phosphoric acid would contain about 6 per cent. phosphorus, and 18 per cent. of phosphoric acid would be equivalent to nearly 8 per cent. phosphorus.

MISLEADING NAMES.

Acid phosphate is sometimes sold for just what it is, but more often it has some misleading name attached to it, as "Soluble Bone," "Dissolved Bone," "Wheat Special," "Dissolved Phosphate," etc., etc. Any material showing 10 to 18 per cent available phosphoric acid, and nothing else, may safely be assumed to be a plain acid phosphate. It has been supposed that the phosphate beds owe their origin to the bones of primeval animals, but the substance is now just as truly a rock as is common limestone, and the evident purpose of calling an acid phosphate a “dissolved bone" is to deceive those who have a prejudice against "rock goods."

SOURCE OF FERTILIZER PHOSPHATE.

Animal bone was the first discovered source of fertilizer phosphate, the effect of broken or pulverized bones on the growth of plants having been noticed at an early date. When chemists began to turn their attention to agricultural problems they found that the active principle of bones was phosphorus. When this discovery was made the next step was to make use of rocks containing phosphorus, but these were found to be practically inert in their natural condition. The discovery that rock phosphate could be made available by treatment with sulphuric acid was first put into practical effect by John Bennet Lawes of England, and his work opened the door to the great fertilizer industry of today.

BONE MEAL.

Raw bone meal has been a favorite fertilizing material, but a 7-year test by the Ohio Experiment Station, in which 200 pounds per acre each of raw and steamed bone meal have been used side by side in a rotation of corn, wheat and clover, has given the following results:

Other experiments have shown that this soil is especially responsive to phosphorus, and to this fact, as well as to the finer condition of the steamed meal, is apparently due the result attained. The station has made no direct comparisons between steamed bone meal and acid phosphate, but the general outcome of its work indicates that the pound of phosphorus is practically as effective in one of these materials as in the other. Whether to use the one or the other, therefore, depends upon the cost per pound of the phosphorus contained, after making allowance for the nitrogen carried in the bone meal.

EXCESSIVE USE OF ACID PHOSPHATE.

It is true that the excessive use of acid phosphate will tend to increase acidity on soils deficient in lime, but experience has shown that when the lime supply is so low that acid phosphate will produce this effect it is time to begin liming, and when this is the case the additional quantity of lime required to neutralize the effect of an ordinary use of acid phosphate is so small as to make this point a negligible matter.

THE COMPOUNDING OF A FERTILIZER.

Having these three or four materials at command, it is an extremely simple proposition in arithmetic to mix them together so as to produce any desired formula. Suppose, for example it is desired to compound a 1-8-1 fertilizer; that is, one containing 1 per cent. "ammonia," or 20 pounds per ton, 8 per cent. "phosphoric acid," or 160 pounds per ton, and 1 per cent. "potash," or 20 pounds per ton. Fertilizer "ammonia" is a compound of nitrogen and hydrogen containing about 82 per cent. nitrogen and 18 per cent. hydrogen. Nitrate of soda, as has been stated, is sold to contain 151⁄2 per cent nitrogen, which would be equivalent to practically 19 per cent. "ammonia." To furnish the 20 pounds of ammonia in our formula would therefore require 110 pounds of nitrate of soda. The standard grade of acid phosphate contains 14 per cent. available "phosphoric acid" or 14 pounds per hundred; it would therefore require as many hundred pounds of acid phosphate to furnish 160 pounds of phosphoric acid as 14 is contained in 160, which is a little less than 111⁄2 times. As above stated, muriate of potash is 50 per cent., or one-half actual "potash." It would therefore require 40 pounds of the muriate to furnish the 20 pounds of potash required in the formula. Adding these materials together we get the following result:

This statement shows that it has required only 1,300 pounds of these three materials to give the number of pounds of ammonia, phosphoric acid and potash necessary to give the percentage in a ton of fertilizer called for by our formula. We therefore have the option of either adding 700 pounds of some sort of makeweight-good dry sand or earth is as good as anything-to bring up the weight to a ton, or of using the fertilizer at a smaller rate per acre. In other words, 130 pounds of this mixture, just as it stands, will produce the same effect as 200 pounds after the dirt or other makeweight has been added, while this makeweight will add nothing whatever to the value of the "ertilizer except to give the user a little more exercise in handling it and the railroads a little more freight, when it is purchased in the ready-mixed fertilizer.

COST.

If the material for this mixture were purchased by the single sackful the cost should be about 234 cents per pound for the nitrate of soda, 212 cents for the muriate of potash, and 80 cents per hundred for the acid phosphate.* At these rates the ton of fertilizer would cost, exclusive of mixing, as follows:

*The retail price of 14 per cent. acid phosphate runs from $14.00 to $18.00 per ton, in Ohio, the price depending upon the information of the purchaser. Muriate of potash has been offered at $4.60 for a 200 pound sack, or $46.00 per ton. delivered at any Ohio point.