The total weight of food eaten, and feces and urine excreted by each steer for five days.

Percentage of fertilizing material in the food, feces and urine.

Fertilizing elements excreted by each steer for five days.

Fertilizing elements in food and the average amount excreted for each experiment. Five days.

In the table that follows there are given the values of the fertilizing constituents of the total excreta in each experiment and of the resulting manure from 100 pounds of each feed, provided both the solid and liquid excreta are saved. In the calculations the values for the same materials assumed for commercial fertilizers in 1904 are used.

47

The money value of the fertilizing elements excreted for each

The figures given in the above tables furnish results which are instructive and may be of considerable value to the farmer. In feeding animals or buying feeds, one is very likely to consider only the feeding or flesh forming value of the feeds, not taking into consideration their effect on the value of the manure produced. When more manure is needed than can be made and the supply has to be frequently supplemented with commercial fertilizers, the purchase of high priced feeds rich in fertilizing material is oftentimes the most economical on account of the increased value of the manure they make. In the preceding table it will be seen that for every 100 pounds of cottonseed meal fed, about $1.18 worth of fertilizing material was given off in the excreta when everything is saved.

Another important fact can be learned from the table on page 47 which shows the amount of fertilizing elements in both the solid and liquid excrements. It will be noticed that the larger part of the nitrogen, the most expensive element, and potash are given off in the urine, hence the importance of saving all of this most valuable part of the manure. Not only are other elements found in large quantities in the liquid, but they are in much more available form than in the solid.

Phosphoric

acid.

Potash.

Total value.

FERTILIZER INSPECTION.

CHAS. D. WOODS, Director.

J. M. BARTLETT, Chemist in Charge of Fertilizer Analysis. The law regulating the sale of commercial fertilizers in this State calls for two bulletins each year. The first of these contains the analyses of the samples received from the manufacturer, guaranteed to represent, within reasonable limits, the goods to be placed upon the market later. The second bulletin contains the analyses of the samples collected in the open market by a representative of the Station.

In the tables which follow the discussion there are given the results of the analyses of the manufacturers' samples of licensed brands. The tables include all the brands which have been licensed to February 1, 1906. Dealers are cautioned against handling any brands not given in this list without first writing the Station.

The figures which are given as the percentages of valuable ingredients guaranteed by the manufacturers are the minimum percentages of the guarantee. If, for instance, the guarantee is 2 to 3 per cent of nitrogen, it is evident that the dealer cannot be held to have agreed to furnish more than 2 per cent, and so this percentage is taken as actual guarantee. The figures under the head of "found" are those showing the actual composition of the samples.

The chief use of fertilizers is to supply plant-food. It is good farming to make the most of the natural resources of the soil and of the manures produced on the farm, and to depend upon artificial fertilizers only to furnish what more is needed. It is not good economy to pay high prices for materials which the soil may itself yield, but it is good economy to supply the lacking ones in the cheapest way. The rule in the purchase of costly commercial fertilizers should be to select those that supply, in the best forms and at the lowest cost, the plant-food which the crop needs and the soil fails to furnish.

Plants differ widely with respect to their capacities for gathering their food from soil and air; hence the proper fertilizer in a given case depends upon the crop as well as upon the soil.

The fertility of the soil would remain practically unchanged if all the ingredients removed in the various farm products were restored to the land. This may be accomplished by feeding the crops grown on the farm to animals, carefully saving the manure and returning it to the soil. If it is practicable to pursue a system of stock feeding in which those products of the farm which are comparatively poor in fertilizing constituents are exchanged in the market for feeding stuffs of high fertilizing value, the loss of soil fertility may be reduced to a minimum, or there may be an actual gain in fertility.

CONSTITUENTS OF FERTILIZERS.*

The only ingredients of plant-food which we ordinarily need to consider in fertilizers are potash, lime, sulphuric acid, phosphoric acid, and nitrogen. The available supply of sulphuric acid and lime is often insufficient; hence one reason for the good effect so often observed from the application of lime, and of plaster, which is a compound of lime and sulphuric acid. The remaining substances, nitrogen, phosphoric acid and potash, are the most important ingredients of our common commercial fertilizers, both because of their scarcity in the soil and their high cost. It is in supplying these that phosphates, bone manures, potash salts, guano, nitrate of soda, and most other commercial fertilizers are chiefly useful.

The term "form" as applied to a fertilizing constituent has reference to its combination or association with other constituents which may be useful, though not necessarily so. The form of the constituent, too, has an important bearing upon its availability, and hence upon its usefulness as plant food. Many materials containing the essential elements are practically worthless as sources of plant food because the form is not right; the plants are unable to extract them from their combinations; they are "unavailable." In many of these materials the forms may be changed by proper treatment, in which case they become valuable not because the element itself is changed, but because it then exists in such form as readily to feed the plant.

Nitrogen is the most expensive of the three essential fertilizing elements. It exists in three different forms, organic nitrogen, ammonia and nitrate.

*Farmers' Bulletin 44 of the U. S. Dept. of Agriculture, "Commercial Fertilizers, Composition and Use," can be had free by applying to your Congressman.