1908.] 



Farmyard Manure. 



17 



the active nitrogen, i.e., that urea had been transformed into 

 ammonium carbonate and volatilised or broken up with loss 

 of free nitrogen, but also that some of the active nitrogen had 

 been converted into an insoluble form, as though the bacteria 

 swarming in the dung had seized upon the active nitrogen and 

 converted it into the insoluble material of their own substance. 

 Of course, this withdrawal of nitrogen from the active into the 

 insoluble form still further reduces the value of the dung as a 

 whole. 



In France, experiments were carried out on the same question 

 by MM. Muntz and Girard with omnibus horses, cows and sheep ; 

 they showed that with horses and milking cows, where the 

 manure was removed every day, the loss of nitrogen amounted 

 to from 30 to 35 per cent, of the total nitrogen contained in the 

 food. With sheep the losses were still higher. Liberal littering 

 and immediate treading of the excreta into it by the animal 

 greatly reduced this loss. The results are given in Table IIL 

 It is apparent that on the whole the proportion of the nitrogen 

 recovered in the manure is about one-half of that supplied in 

 the food. 



Experiments of the same kind have also been carried out on 

 the farm of the Royal Agricultural Society at Woburn for some 

 years, and the results obtained in 1899, 1900 and 1901 are given 

 in Table IV. The animals were fed in deep boxes with cemented 

 bottoms and sides and the dung was not removed until the 

 feeding experiment had concluded ; it was then weighed and 

 samples taken for analysis. The manure was then in the early 

 winter made up in a heap in the open on ground beaten down 

 hard and covered thoroughly with earth. No liquid appeared 

 to drain away, and in the spring the heap was again weighed 

 and sampled before application to the land for the root crop. 

 Here again the loss of nitrogen in making the dung under the 

 best conditions varied from 13 to 18 per cent., while the making 

 into a heap and storage brought up the loss to 33-37 P er cerrt - 



Wood at Cambridge has also estimated the losses irfvolved 

 during the making and storage of farmyard manure. In his 

 experiments four heifers were tied up and fed, one pair on 

 mangels, hay, and straw alone, the other pair on the same foods 

 with the addition of decorticated cotton cake. The feeding 

 went on for eighty-four days in boxes with well rammed clay 

 (3?88) " b 



