ORGANIC MANURES.

Lyttelton Times, Volume CXIV, Issue 16192, 19 March 1913, Page 10

ORGANIC MANURES.

The name V organio manure" is given to all manures having an animal j or vegetable origin,-in contradistinc- ' tion' to those which have a distinctly mineral origin, known as mineral manures or chemical fertilisers, such as superphosphate, basic slag, nitrate . of soda, etc. I The best-known of the organio manures is, of course, farmyard ! manure. It possesses the great advan- i tage that it contains all the principal elements of plant food, as may be easily understood when its origin is considered. It is a mixture of the excreta of animals with the material I in which they are littered. The relative value of farmyard I manuro depends on various ciroum- ,' stances, such as the kind of animal producing it, the age of the animal, the food of the animals, condition of i the manure, etc. The dung of horses and sheep is called "hot," it is dry, ferments rapidly, and is difficult to preserve. It is suitable for cold soils, and for vegetables of rapid growth. The dung of cattle i and pigs is not of such a heating j oharncte" and decomposes more slowly. When possible, it is a good plan to : mix the two classes of dung together, to obtain the average best quality. According to Mr Hall, the analyses; of a large number of analyses at Rothamsted show that farmyard j manure contains about three-quarters ; of its weight in water, about two-thirds of 1 per cent of nitrogen, one-quarter of 1 per cent of phosphoric acid, and one-thircl of 1 per cent of potash, or, j per ton, about 151 b of nitrogen, 51b \ of phosphoric acid, and 71b of potash, j The composition, ho adds, varies very ; greatly, both with the nature and feeding of the animals and the treatment | | and storage the manure receives. Farmyard manure, carelessly kept, i loses especially its nitrogen and potash. ; To neglect the proper management of j such a valuable substance is equiva- j lent to throwing money away. j If one simply compared the propor- ' \ tion of plant nourishment in farm-1 \ yard manuro and chemical fertilisers, ■ it might bo thought economical to re- j place the bulky organic manure almost , entirely by the concentrated fertilisers. : Such a practice, however, would be '.-. very ill judged, because mineral fer-1 tilisers cannot take the place of farm- i yard manure, except to a certain ex- j tent. Farmyard manure contains, in addition to plant food, a substance of great importance—"humus." Another organic manure that has played a distinguished role in agricul- . ture is Peruvian' guano. It is purely organic, being the excreta and debris of sea birds, deposited in the drji ; regions of Peru. It still comes over in I considerable quantities, and is recog- | nised as about the best and safest j manure a farmer can employ. | Fish guarno, wool waste, horn shav-; \ings, dried blood, rape cake, arc all useful forms of organic manures, sup- j plying, during decomposition, nitrogen j |to the crops. With these waste sub--1 stances it is important to remember, their povertv in phosphoric acid and potash, so that when applying waste orsranie FubstarieeS some phosphates and potash should also be used. Green manuring constitutes another form of organic manuring. A leguminous crop collects its roots, a considerable proportion of nifcrogont from the air. and when a croo of that nature is ploughed under, the following crop , pets the benefit of the collected nitroI gen. but bore again the necessity of applying phosphate and potash should not he overlooked. I Comnnsts made by mixtures of all serfs of vegetable refuse, dead leaves, hnroHiold rofu=e. etc., are valuable, their qualitv depending on their composition.: thev are more especially suitnble for>nnl«ns and horticulture than for general farm 'praptice.