178 AGRICULTURE 



will, as a result of fermentation, lose about 

 20 per cent, of its organic matter ; so that 

 in. order to ascertain the approximate quantity 

 that will be available for distribution to the 

 land, we must reduce the weight of fresh 

 dung by one-fifth. 



One may also make a useful estimate of 

 the probable output of farmyard manure if 

 one has an approximately accurate idea of 

 the amount of straw at the farmer's disposal 

 for feeding to cattle and for use as litter. 

 It is usually assumed that for each ton of 

 straw consumed at the homestead about 

 3 tons of farmyard manure should later be 

 available. Suppose the case of a farm of 

 200 acres which is worked upon the four- 

 course shift, and where, therefore, of the 

 whole tillage area, one-half (100 acres) is 

 under corn crops, and one-fourth (50 acres) 

 under roots. Such a farm will produce 

 about 120 tons of straw, equivalent to about 

 360 tons of farmyard manure, and if this 

 is distributed equally over half the root 

 break the land will receive about 15 tons 

 of dung per acre, which is approximately 

 what farmers usually expect in practice. 

 This relationship of 1 ton of straw to 3 tons 

 of farmyard manure is also taken as the 

 basis of calculation, when straw is sold off 



