TABLE III SHOWING THE COST OF THE DIFFERENT INGREDIENTS IN CERTAIN FERTILIZERS DURING 1904 when the cold cow and pig manure will tend to prevent excessive loss, by heating, from the horse maYoung growing animals and those bearing young and giving milk will give poorer excrete than nure. mature fattening animals. The food and the litter used also affect the value of the manure. In barn manure the nitrogen, phosphoric acid and potash are slowly available, and are arbitrarily reckoned to be worth half what they would cost in fertilizers. The value of a ton of manure for its physical effect upon soils cannot be expressed in dollars and cents, but in the Eastern States it may be presumed to vary between 50 cents and $1.00 per ton; for while the fertilizing ingredients show a value of about $1.25, the manure often costs, or is valued at, $2.00 per ton. Mixing Fertilizers.-Fertilizer manufacturers lay great emphasis on the value of proper mixing, and usually charge from $5 to $10 per ton for doing it. For example, a commercial potato manure analyzing nitrogen, 3 per cent., phosphoric acid, 6 per cent., and potash, 10 per cent, costs in New Hampshire', in 1904, $36.50 per ton. A fertilizer made up by the station on the same formula was just as satisfactory, and after allowing $1.00 per ton for mixing, it cost $24 per ton, a saving of $8.50 per ton, or using 1,500 pounds per acre = $7.10 per acre. To compound this fertilizer: 3 per cent. nitrogen 60 pounds nitrogen in a ton (2,000 pounds). 6 per cent. phosphoric acid = 120 pounds phosphoric acid in a ton. 10 per cent. potash = 200 pounds potash in a ton. Nitrate of soda will furnish nitrogen for immediate use, and the nitrogen of the sulphate of ammonia will 1 N. H. Bul. III., p. 110. become available later on, hence we may take 234 pounds nitrogen in the form of nitrate of soda, and 3634 pounds in the form of sulphate of ammonia. Cottonseed-meal, dried blood, tankage, etc., might also be used if desired. Nitrate of soda containing 151⁄2 per cent. nitrogen; to fur- Muriate of Potash containing 50 per cent. potash; to furnish 200 pounds potash it requires 400 pounds Filling, sand, etc., used to make weight if desired Pounds 150 184 750 400 516 2,000 Unless care be taken in mixing fertilizers loss of valuable ingredients may result. 1. Nitrate of soda and soluble phosphate of lime—as, acid phosphate-must not be mixed and allowed to stand for any length of time, or chemical action. will take place, resulting in a loss of nitrogen and phosphoric acid. 2. Do not mix an ammonium salt-as, sulphate of am monia—with any other fertilizer containing free lime, as the lime will set free the ammonia, which will be lost. 3. Do not mix soluble and insoluble phosphates together. 4. Nitrate of soda is very deliquescent, and if left mixed with other fertilizers is liable to render the whole mass wet and pasty, and so difficult to apply. Cottonseed-meal is a very useful source for part of the nitrogen of mixtures. If it is necessary to hold a quantity of nitrate of soda for a time, it is advisable to empty it out of the bags, as they are liable to ignite spontaneously. When emptied do not leave the bags lying in a heap in the corner of the barn. Store nitrate of soda in a dry place. 5. Kainit is also very deliquescent, and it is the worst potassic fertilizer to use in a mixture on this account. Sulphate or muriate of potash are better for mixtures. Applying Fertilizers.-When a horse planter is used the fertilizer is usually distributed in the row at the time of planting. The fertilizer may be sown broadcast or in the rows as desired, but it should be incorporated with the soil and not left on top. Water Requirement.—It has been shown clearly that the available water content of the soil exerts a great influence upon the life of the potato plant, upon its assimilation of plant-food, and upon the yield. At the Wisconsin Experiment Station' it was found that when two acre inches of water were added in two irrigations in one case the yield was increased 100 bushels of salable potatoes per acre, thus showing that the right amount of water at the right time is a very important factor in determining the yield. Whitson, of 2 1 Wis. Report, 1999, p. 213. 2 Wis. Report, 1902, p. 190. 3 2 Wisconsin, shows that if it is assumed that under the existing climatic conditions of that State 18 inches of rainfall during the growing season is sufficient for potatoes, then, on this basis, there was a shortage of 4 inches or more in ten of the past twenty-one years. In Utah' it was noted that the largest yield was obtained from a plat irrigated every eighth day and receiving 14 inches of water, and another year 16.62 inches of water with practically no rain produced a yield of 423 bushels per acre. The importance of water was also shown at the same station, when amounts of water varying between 4.3 inches and 9.45 inches were applied between July 18 and August 6, and the yield increased with the increase in amount of water. At the New Jersey Station' irrigation increased the yield 36.4 per cent., while at Wisconsin the increase has been 159.58 bushels per acre over the unirrigated plat, and the average gain per year during the six years-1896-1901-was 83.9 bushels per acre. That some risk must be taken in irrigating heavy soils in a humid climate was demonstrated at Wisconsin." Thus, in one year, while there was an increase of 81.4 bushels per acre from irrigating sandy land, on heavier land the yield was reduced 56 bushels per acre because heavy rain followed the second irrigation. 5 Corn and potatoes require somewhat similar amounts of water to make one pound of dry matter. The figures of Wilfarth and Wimmer' and Whitson are as follows: 1 Utah Report, 1893, p. 180. • Utah Bul. 5. Wis. Report, 1901, p. 198. 'E. S. R., XIV., p. 561. 2 Utah Bul. 26, p. 14. 4 N. J. Report, 1900, p. 184. |