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animals contributing to its formation,—cattle, horses and swine,—some one or two of which may be absent; upon the fodder rations employed in feeding the stock; upon the export of milk from the farm; upon the quantity of foreign matter incorporated as bedding, or absorbents; upon the percentage of the urine and dry excrement, and upon the way in which it has been preserved, whether properly housed, or exposed to the leaching of rains and winds.
The Value of Manure as a fertilizer has been appreciated for generations. The investigations of science have not displaced its standing, or curtailed its use. For it is both the cheapest, and, all things considered, the best general manure at hand. It will always be
used whenever the soil requires fertilizing, and where live stock is kept. It meets the wants of the general farmer better than any other fertilizer, and its application is understood, and its general effects are well known.
The feed has a great effect upon the quality of the manure. In its passage through the animal, the food loses what is taken out by the growth of the animal and by the milk. A good deal of carbonaceous matter, which has no fertilizing value, is also burned in the system to supply animal heat, but all the rest of the food passes into the dnng or urine. The digested food is voided in the urine, the undigested in the solid manure. Of the two. the urine is the more valuable; it is also more difficult to preserve. Other things being equal, the richer the food, the richer the manure. It is calculated from Table IV of fertilizer analyses, that a ton of average manure contains about 1350 pounds of water, 475 pounds of organic matter and 175 pounds of ash. The latter contains, of potash eleven pounds, phosphoric acid eight pounds, lime six pounds, magnesia four pounds and the rest is sand, carbonic and sulphuric acids, iron, alumina and soda. The organic matter contains about ten pounds of nitrogen. Manure from poorly fed stock, especially if absorbents are not used on the manure pile, if exposed to the weather, may not contain half these quantities. On the other hand, richly fed stock, carefully bedded, may yield manure twice as rich in plant food as the average just stated. This shows the wide variety that may exist in manure.
Comparing the actual requirements of a crop of tobacco of 1800 pounds cured leaf and stalks, with the amount of plant food contained in barn manure, it appears that 15 tons (or about four cords) of average manure contain the 154 pounds of nitrogen required; 60 tons, or 15 cords, contain the 488 pounds of potash, and four tons, or one cord, contain the 26 pounds of phosphoric acid. This comparison is for the total crop of tobacco, both leaves and stalks, but if the stalks are returned to the land on which they were grown, the apparent amount of manure is much less. To supply the 80 pounds of nitrogen removed in the leaves only, 10 tons, or two and one-half cords, of manure appear to be all that is necessary; 34 tons, or eight and one-half cords, contain the 291 pounds of potash required, while two tons, or half a cord, contain the 12 pounds of phosphoric acid that is necessary.
But every tobacco grower knows it is simply impossible to obtain a crop of 1800 pounds of cured leaf from a dressing of only eight and one-half cords of manure, which is the largest quantity that the figures show is necessary. The trouble is, that the fertilizing elements of manure are not rapidly set free; their action is proverbially slow, and from this slow action comes the great "lasting power" of manure. It is lasting because it cannot be quickly used. The availability of the manure is increased, but at the loss of considerable of the nitrogen, by rotting, especially when assisted by working over the pile, breaking up the lumps, and allowing the air free access to all parts of the heap.
But eight and one-half cords of manure, however short and well rotted it may be, will not satisfy the re
no. 14. WOODEN FRAME FOR PLANT BED (German).
quirements of the crop. It is likely that not more than thirty per cent of its fertilizing elements can be used by tobacco the first year, although this percentage is governed considerably by the length of time the manure remains in the soil before the plants are set, and upon temperature and moisture. Yet the longer it thus remains in the soil, the more likely is the loss of nitrogen from evaporation and leaching. This loss is again offset by the uniform distribution of what nitrogen is not thus lost, and the more available form in which it exists.
It is, therefore, very difficult to tell how much manure to use, if that, alone, is to be depended upon, not because the quantity of plant food it contains is unknown, but because of the impossibility of determining how much of it is available for the demands of the rapidly growing tobacco crop. If all the plant food is not consumed the first year, especially the potash and lime, it remains in the soil for the use of future crops. Owing to the very slow action of manure, and the great demands of tobacco, occasioned by the very rapid growth of the plant, it is difficult to bring about a satisfactory state of fertility from manure alone. And in the great majority of instances, manure is no longer expected to supply the entire amount of plant food, but is supplemented by the use of other materials.
Effect of Manure on Soil.—While manure is thus of questionable dependence, alone, for tobacco food, it possesses certain valuable qualities arising from the large quantity of vegetable matter which it contains. This vegetable matter is beneficial in many ways. It supplies a stock of vegetable mold, or humus, that is often lacking in the light soils on which tobacco is grown. This humus absorbs moisture and heat, and retains the nitrates set free in the soil. This valuable adjunct to the proper state of fertility, is too often overlooked by the advocates of exclusive chemical fertilizers. The mechanical effect of manure is also of great consequence, as it lightens very heavy soils by making them open, porous and easy of cultivation, while it supplies moisture and body to lands that are naturally of too light a nature.
Manure also promotes a quick fermentation that is congenial to all plants, one of the results of which is the conversion of nitrogen from a raw state to nitrates that are suitable for plant consumption. On this account it is used with benefit in conjunction with other nitrogen supplies, especially as it also, in a measure, fixes and retains this soluble nitrogen and thus prevents waste. When used with other quick-acting fertilizers, manure keeps land in good heart, moist, mellow and friable, and in a condition admirably suited to the best development of plant roots. In addition to these peculiarities, the plant food which manure contains is of great consequence, especially as this may come in at the last of the season, when the more available plant food of the chemicals may have been consumed. The lasting quality of manure, which makes it undesirable as an exclusive dependence, becomes a matter of importance when used with other quick-acting fertilizers. For these reasons it is important to use a liberal dressing of manure.
The Best Time to Apply Manure is in the fall, plowing it under slightly, but not too deep. If preferred,
FIG. 15. PLANT BED FRAME WITH CLOTH COVER PARTLY REMOVED.
the dressing can be applied after plowing, when it should be well harrowed in. The rain, snows and frost of fall, winter and spring diffuse the fertilizing elements evenly through the soil, break down the coarse, woody matter of the manure, reducing it to the condition of vegetable mold so essential as an absorbent and for its powers of flxation of other forms of plant food. From eight to ten cords, thirty-five to forty loads, of manure should be thus applied when other fertilizers are to follow. If not done in the fall, it should be applied as early as . possible in the spring, that the mellowing influence of air and moisture may transform it from a crude, raw state to one congenial to the most favorable plant growth. If coarse, rank manure is applied late in