Agriculture. By R. W. Emerson Macivor, F.I.C., F.C.S., &c. Author of "The Chemistry of Agriculture."

Waikato Times, Volume XIX, Issue 1613, 4 November 1882, Page 2 (Supplement)

Agriculture. By R. W. Emerson Macivor, F.1.C., F.C.S., &c. Author of "The Chemistry of Agriculture."

(a.y A farmyard manure varies in composition according to the nature of the animals contributing to it, the character of their food, the proportion of litter, and the care exercised in preserving it from deteriorating influences. A large quantity of the nitrogenous or ammonia producing substances are contained in the urine, and, therefore, if the manure is exposed to rains, and the drainings allowed to waste, serious loss will be occasioned. Investigation has shown box manure ia much superior to that made in the open yard. The system of allowing manure to remain under the cattle for a long neriod, in some instances for three months, in specially constructed deep stalls, has the advantage, as compared with the ordinary practice of manure heaps, that the manure is obtained in more workable condition, the ammoniacal salts better preserved, and the proportion of plant-food constituents greater, in comparison to the mass. The escape of carbonate of ammonia from the manure heap will he considerable, if an inadequate quantity of litter is employed. In order to test the progress of putrefaction in manure heaps, it is recommended that a sample be ,taken from the middle of the mass by means of- a forked stick. If it appears homogeneous, fairly moist, and warm, and with no abnormal smell, the manure is supposed to be ready for use. Should the sample be hot, very dry, and have an ammoniacal odour, the process of fermentation has gone on too rapidly, and may be checked by cold water or putrified urine. If the sample be cold, and pieces of straw are visible, putrefaction is promoted by adding blood to the heap. Eotten manure, when well made in a place sheltered from rain, is much more concentrated than the fresh, having fallen off in weight during decay with but slight loss of useful constituents. Some of the latter have also become more soluble. One ton of good manure contains from 91bs. to 151bs. of nitrogen, a similar quantity of potash, and from 41bs. to Olbs. of phosphoric acid, equal to from lOJlbs. to 39£lbs. of good bone dust. The immediate return from an application of the manure is always much less than from the corresponding amount of plant food applied in good artificial fertilisers. The influence of a dressing farm-yard manure, extends over a considerable number of years, owing to its useful constituents being locked up in the form of compounds which decompose only slowly in the soil. (b.) Seaweed has a manurial value, similar to that of farm-yard manure, and this increases as it loses water. (c.) Guanos are divided into two classes, nitrogenous and non-nitrogenous, or jihosphatic. The former are valuable on account of the ammonia, and other nitrogenous compounds they contain; whereas, the latter are useful for their phosphates only. Peruvian guano is the only member of the first-class at present in our markets, and it is not worth the high price charged for it. Dr. Lawes, the eminent British authority on all scientific matters pertaining to agriculture, says: "At one time the fanner could calculate upon receiving guano, containing nitrogen equal to 16 per cent, of ammonia ; more recently, he had to be satisfied with 14 per cent.; and more recently still, not only a lower average per cent, than this, but great uncertainty whether he wonld receive that amount, half as much, or even less." Peruvian guano has fallen off in quality, but not in price. A wise farmer will invest his money in the purchase of other fertilisers, and forget that this one is|in existence. Lacepede Island, Maldon Island, and other phosphatic guanos may be employed for turnips and other roots on open soils, but are best converted into superphosphate by treatment with vitriol, before they are applied to the land. (d.) Blood and Woollen Refuse are purely nitrogenous manures. The former, when dried, is an excellent fertiliser, containing from 9to 13 per cent, of nitrogen. It readily decomposes in the soil, producing ammonia and nitric acid, and is a really good manure for wheat. Shoddy, and other forms of wool and hair contain from 5 to 10 per cent of nitrogen, according to the quantity of dirt, grease, and other objectionable matter present, They decay very slowly, and their effect extends over many seasons. They are rarely applied to any other crop than hops. (c) Bones are composed chiefly of earthy matter or phosphates, gelatin, and fat. The latter has no manurial value, and is usually extracted by skimming prior to crushing the bones. Commercial bone manure should contain from 44 to 50 per cent, of phosphate of lime, and from 30 to 40 per cent, of nitrogen. Bones which have been deprived of their gelatin are not so valuable for manuring purposes as those which have not been thus treated. The finer that bones are ground the more immediate is their influence. Rotten bone manure acts quicker than the fresh. It is a good plan to place bone-dust in alternate layers with farmyard manure, and permitting both to putrify together in a conical heap, covered up with earth so as to prevent loss.