Page:Encyclopædia Britannica, Ninth Edition, v. 15.djvu/535

Rh MANURE 511 are put in a separate place, or is accumulated under the animal in the feeding-boxes ; of the two plans the latter is the better, the urine being more thoroughly absorbed, and, owing to the box manure being more compact through constant treading on it, air enters less freely and the decomposition goes on less rapidly, the volatile matters in consequence not being so readily lost. External agents, such as rain, wind, sun, Arc., do not affect it as they would in the case of dung-pits. If farmyard manure must be stored in heaps, care should be taken to have the bottom and sides of the pit impermeable to water, and the bottom slightly inclined to allow any liquid manure which collects to run off into a tank below, from which, by means of a pump, it may be again poured over the heap. A concrete bottom for the pit is best, or, failing that, one of thick clay or well-beateu earth. The manure heap should be kept as compact as possible, and always moist. The advantage of farmyard manure lies, not only in its supplying all the con stituents of plant food, but also in the improved physical condition of the soil through its application, as the land is kept porous, and air is allowed free access. While, how ever, farmyard manure has these advantages, experience has shown that artificial manures, properly selected to meet the requirements of the crops intended to be grown, due regard being had to the chemical composition of the soil, may be employed to greater advantage. In farmyard manure about two-thirds of the weight is water and one- third dry matter ; a large bulk thus contains only a small proportion of fertilizing substance*, and expense is incurred for carriage of much useless matter when dung has to be carted to distant fields. When a plentiful supply of good farmyard manure can be produced on the farm or bought at a moderate price in the immediate neighbourhood, it is economy to use it either alone or in conjunction with artificial manures ; but when food is dear and fattening does not pay, or farmyard manure is expensive to buy, it will be found more economical to use artificial manures. Manures from Feeding Stuffs. The investigations of Messrs Lawes, Gilbert, and Mure have shown that, in estimating the value of animal manure, 90 per cent, of the nitrogen of the food may be reckoned to be recovered in the case of feeding cakes, pulse, and other highly nitrogenous feeding stuffs ; 85 per cent, in the case of foods compara tively poor in nitrogen, such as cereals and roots ; and less than 65 per cent, in the case of bulky feeding stuffs, such as hay and straw. As a source of manure, the value of fattening foods is greater the more nitrogen they contain. Practically speaking, the whole of the mineral constituents and about nine-tenths of the nitrogen of the food are recovered in the dung and urine. For the same weight of dry substance consumed, oxen void more manure than sheep, and sheep more than pigs. The composition of the dili erent foods given to fattening animals being well known, it is easy to calculate the amounts of nitrogen, phosphoric acid, and potash of the food which will be recovered in the manure. Each constituent having its market value as a manuring constituent, the money value of the manure obtained from the consumption of a ton of any ordinary food of which the composition is known can be determined. Assuming ammonia to ba worth 8d. per Ih, potash 2d. per Ib, and phosphate of lime Id. per 5&amp;gt;, the money value of the manure produced by the consumption of a ton of various foods is given by Mr Lawes in the following table (VII.), which also shows the general composition of the different foods as far as their manurial value is concerned. In these estimates it is presumed that the manure can be put on the land without loss, but in practice some loss is unavoidable ; it may be but slight, as, for instance, when sheep are fed on the land, or when the manure is made in feeding-boxes, but it will be considerable when the food has been consumed in open yards in a very rainy season. Allowances must thus be made for the circumstances under which the manure was produced. TABLE VII. Composition of Ordinary Feeding Stuffs in IQQO parts, and their Manuring Value per Ton. Dry Matter. Nitro gen. Potash. Phos- plioiic Acid. Money value of the Manure from One Ton of &amp;lt; ach Food. 1. Cotton seed cuke (decor ticated) j-900 66-0 310 312 . s. d. G 10 2. Rape cake. 900 48-0 13 2 3. Linseed cake 885 45 14 7 19 6 4. Cotton cake (undecorti- catei) j-885 370 20-1 22-9 3 18 6 5. Linseed 905 SG O 12 3 G. Palm-kernel meal (Eng lish) j-930 25-0 12-2 2 10 7. Pease 800 36 9 8 8 8 8. Beans 850 40-0 12-0 ll G 9. Lentils 880 43-0 &amp;lt;&amp;gt;-o g-ij 10. Malt dust 905 38-0 19-5 17 2 456 11. Bian 8G5 25-0 14-8 36 1 12. Oats. 8 GO 20 45 G 2 13. Wheat 850 180 ,V4 8-0 I 13 14. Barley 840 16 5 4-9 7 3 1 10 15. Maize 880 160 3- G l 1 11 16. Locust beans 850 12 5 3-5 5-8 126 17. Tans 840 42-0 6 6 1G 3 3 13 6 18. Coarse pollard... &quot;!.. 860 25-8 14-9 34-2 2 18 19. Fine pollard 860 2G-0 14-6 30-3 2 17 20. Malt 950 17 G 5 7-3 1 11 G 21. ( lovfr liny 840 23-0 19-5 5-6 2 5 G 22. Meadow liny 8-10 14 6 16 8 3 8 1 10 6 23. B an straw .... 8 5 10-0 ll l 41 1 G 24. Wheat straw 840 4-0 5-8 2 6 12 G g.-,0 5-0 0-7 10 9 20. 0&quot;.t straw 830 5-0 lt -4 13 27. Pea straw 840 0-3 8 9 3 8 18 9 2?. Potatoes 250 3-5 5 G 1 8 070 29. Mangolds 115 2-0 3 9 7 053 SO. Swedes 107 2-3 2-0 G 043 31. Carrots 142 2-0 3-2 I D 040 32. Turnips 82 19 2-9 6 040 33. Parsnips 150 2-2 3 G 17 056 Artificial Manures. By some a distinction has been drawn between those manures which, like superphosphate, dissolved bones, &c., are manufactured in chemical works and those which are produced naturally, such as guano, nitrate of soda, &c. However, the term artificial manure is generally applied to all manures, natural or manufactured, which are not produced on the farm, as distinguished from farmyard manure and manure from purchased foods, whk-h are essentially farm products. The value of all manures mainly depends on their chemical composition. As compared with farmyard manure, artificial manures have the disadvantage that they, unlike it, do not improve the physical condition of the soil. Artificial manures have, on the other hand, the advantage over farmyard manure that they can supply in a small compass, and even if used in small quantity, the needed nitrogen, phosphoric acid, and potash, &amp;lt;fcc., which crops require, and which farmyard manure has but in small proportion ; they present the expensive fertilizing matters in a concentrated form, and by their application save expense in labour and carriage. The following are the principal artificial manures in use : 1. Nitrogenous Manures. Peruvian Guano. This is a natural manure, valuable on account of the ammonia, phosphoric acid, anil potash it contains. It is the excrement, &c., of sea birds accumu lated in parts where no rain falls. The earliest deposits found contained as much as 14 to 17 per cent, of ammonia, e.g., Chinclias Island guano ; those now (1882) imported seldom exceed 8 percent, and generally vary from 4 to 8 percent., of ammonia. In using guano it should be mixed with earth, &c. , to prevent injury to the seeds or plants. Peruvian guano is also treated with sulphuric acid, which renders the phosphates soluble and fixes the ammonia, thereby preventing any loss of it ; this constitutes dissolved guano, and w frequently sold upon a guarantee of 20 per cent, of soluble phosphates, 4 per cent, of insoluble phosphates, and 9 per cent, of ammonia. Peruvian guano is used as a top dressing for wheai and barley ; in addition to insoluble phosphates, it contains soluble phosphates of the alkalies.