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IRISH GARDENING. 



Farmyard Manure. 



By M. J. JAMISON, Associate of the Royal College of Science for 

 Ireland. 



I ELL made farmyard manure 

 constitutes the backbone of 

 intensive cropping^. By " well 

 made " is meant (i) where the 

 farm animals are well fed 

 according' to the uses for 

 which they are kept, (2) where 

 the manures from the various 

 animals are mixed tog^ether to render the whole 

 uniform, (3) where the g'reatest care is taken to 

 prevent undue heating and also loss by drainag'e 

 from the heap. When store cattle and cows 

 are fed on turnips and straw the manure pro- 

 duced from a ton of this feed, allowing for 

 storage under average circumstances, may be 

 valued at three shillings and ninepence. If a 

 fair allowance of decorticated cake is added, the 

 value of the manure from a ton of the mixture 

 fed will be eight shillings and sevenpence. 

 The best manure is that obtained from fattening 

 animals and working horses. Young stock and 

 milk cows give the least valuable manure. 

 Hence the necessity for mixing these various 

 manures, so as to get uniformity in the mass. 

 Much heating causes loss of ammonia, the most 

 valuable constituent of the manure. Loose 

 heaps and those containing much straw, 

 also the manures from fattening animals and 

 horses, have a great tendency to heat. The 

 greater part of the nitrogen and potash, voided 

 by animals, passes out in the urine. These 

 valuable constituents, being more or less soluble, 

 are easily washed away should much rain-water 

 get at the heap, or if the heap is placed on 

 sloping ground and not surrounded by some 

 absorbent material. For these reasons the 

 heap should be kept compact, free from the 

 water off eaves and yard, occupy the smallest 

 space compatible with its cubical contents, and 

 be surrounded where possible by loamy earth to 

 absorb the liquid manure and volatile ammonia. 

 Manure heaps are often found in hollow parts 

 of the yard Waterlogging decreases the 

 organic matter of the manure, thus decreasing 

 its humifying powers. Waterlogged manure 

 is a breeding ground for those forms of bacterial 

 life not beneficial in farming. The best method 

 of preserving farmyard manure is to have it 

 well trampled under the animals producing it, 

 or to wheel the liquid and solid manure into a 

 shed, where it can be trampled firm by stock. 

 The loss of nitrogen under such cases is 13 per 

 cent., but if kept in heaps in the open, even 

 under the best conditions, the loss approaches 

 40 per cent. The manure is kept firm and 

 moist with no oxidation, unless around the 

 walls, if rough and openly built. The carbonic 



acid gas produced in decomposition, also that 

 from the animals, tends to convert the volatile 

 ammonium carbonate into an acid, and therefore 

 stable, carbonate oi' ammonia. This manure, 

 when carted to the drills in spring time, is placed 

 high, dry, well aerated, and in the best position 

 for nitrification. No waste of nitrates from wash- 

 ing out can take place, nor denitrification of the 

 nitrates formed, or of those added in the form of 

 artificial manures. If we place dung, wet soil, 

 and nitrate of soda in a fiask, denitrification of 

 the nitrate sets in, so that much loss occurs. 

 Hence the manuring of wet soils under horse 

 cultivation is attended by waste. Ploughing 

 in of dung in our wet climate tends to keep the 

 land wet in winter, delays spring operations, 

 and is wasteful of the manure, as it must be 

 stored during the previous summer to enable 

 the stubble land to be ploughed in time. 

 During summer nitrification goes on rapidly in 

 manure heaps, and the nitrates produced will be 

 washed out by heavy rains or denitrified when 

 applied in winter. The escape of ammonia from 

 cow-droppings on grass land can easily be 

 demonstrated where moulds are growing on the 

 surface. In intensive cultivation, where crops 

 are grown in quick succession and where the 

 dung cannot be trampled under cattle, the 

 manure should be carted to the fields and mixed 

 with one-fourth of its weight of loamy soil, and 

 one-twelfth of the total weight of cold, dry 

 carbonate of lime incorporated with the 

 mass. This will produce a well-decomposed 

 manure with much quickly available plant food. 

 In considering poor hill-side soils, farmyard 

 manure, besides supplying plant food, enables 

 them to absorb and retain moisture, keeps them 

 more open, renders them alkaline, and supplies 

 food for those useful organisms, soil bacteria, 

 on whose relative numbers true soil-fertility 

 depends. Artificial manures may stimulate 

 crops, but have the opposite effects to those 

 mentioned. Where cow-droppings have de- 

 cayed on poor grass lands many millions more 

 bacteria are found per cubic centimeter than 

 where no droppings are. But the most bene- 

 ficial use of farmyard manure is that in com- 

 bination with carbonate of lime. Here are the 

 best conditions for the nitrifying organisms to 

 work. Nitrates are readily formed from the 

 dung and built up as nitrate of lime. The 

 conditions are also suitable for those organisms 

 which can build up the nitrogen of the air in 

 their bodies. In no other way can one account 

 for the excellent crops produced on poor hill- 

 sides by the use of a moderate amount ot dung 

 and carbonate of lime, with a dressing of 

 phosphates and potash once in the rotation, 

 otherwise than by the action of these organisms 

 developing in the humus, and aided by the 

 carbonate of lime, producing nitrates in com- 



