BARNYARD MANURE 97 



of straw or other coarse material, most of the rain will be 

 absorbed. The water-tight bottom prevents loss by leaching. 

 A pit with a tamped-clay bottom is fairly satisfactory, but one 

 with a concrete bottom is better. 



Sometimes, where much bedding is used, the manure may be 

 allowed to accumulate in the stables, although this is not usually 

 practicable in horse stables. Where cattle or sheep are fed, 

 one of the most practical and satisfactory methods of handling 

 manure is to feed the animals under a large shed, if the climate 

 is not too severe, and allow the manure to accumulate during 

 the winter. In such cases the animals keep the manure moist 

 and well compacted, thus retarding rapid fermentation ; and as 

 the manure is sheltered from the rain, there is no loss from 

 leaching. The bedding and waste of the feed are mixed with 

 the manure, and the whole makes a manure of good quality. 

 It is sometimes practicable to put the manure from the horse 

 stables into the cattle sheds, where it is mixed with the cattle 

 manure, and the whole is preserved together. 



107. Reenforcing barnyard manure with phosphates. Aver- 

 age barnyard manure is somewhat lower in phosphorus than in 

 nitrogen and potassium, due to the fact that considerable quan- 

 tities of phosphorus are retained in the bones of the animals, 

 especially if the animals are growing rapidly. Consequently 

 it is often wise, particularly on soils deficient in phosphorus, 

 to add phosphates to the manure before the manure is applied. 

 An interesting experiment upon this question has been per- 

 formed. 1 Two grades of manure were used, one (called stall 

 manure) taken directly from the stable, the other (called yard 

 manure) such as had accumulated in a heap in the open lot. 

 Each of these two kinds of manure was divided into three lots, 

 one lot of each kind receiving 40 pounds of rock phosphate 2 

 per ton, another 40 pounds of acid phosphate 3 per ton, and the 



1 Ohio Experiment Station, Circular 13, p. 645. 



2 A finely ground rock containing about \2\ per cent of phosphorus. 



3 Phosphate rock after it has been treated with sulphuric acid to make the 

 phosphorus more readily available to growing plants. 



