161 



GRERNT MANURING COMPARED WITH FEEDING THE CROP. 



In spit ; of the many advantages of green manuring, there are con- 

 ditions under which it can not be regarded as a rational and profitable 

 practce. It involves the absolute waste of large quantities of the very 

 best kind of fodder. For th ; s reason green manuring on good soils 

 can only be recommended when the conditions of farming do not admit 

 of the careful preservation of manure. The crops should be fed to animals 

 and the manure carefully saved and returned to the soil. It is in this 

 manner only that the full value of the crop can be secured. By feeding 

 the crop this animal food is saved, and at the same time from three 

 quarters to nine tenths of the fertilising materials (nitrogen, phos- 

 phoric acid, an 1 potash) in the crop may be returned to the soil in the 

 manure, if this is properly cared for. Animals need for their nutrition 

 nitrogen, fat, and carbohydrates (starch, sugar, etc). The nitrogen in 

 foods is in the form of protein (albuminoid materials). It is the same 

 nitrogen which in green manuring enriches the soil. These leguminous 

 crops are unusually rich in protein — far richer than most other coarse 

 fodders. For instance, while hay from grasses contains from 6 to 8 per 

 cent, of protein, red clover hay contains 12.5 per cent, alfalfa hay 14.3 

 per cent, and cowpea hay 16.6 per cent of protein. If grass hay and 

 corn are fed, such concentrated feeding stuffs as cotton-seed meal, 

 gluten meal, linseed meal, etc , must be fed to make up the supply of 

 protein needed. If leguminous crops are fed, much less grain will be 

 required. 



As nitrogen is the most expensive fertilising element, so protein 

 (nitrogen) is also by far the most expensive food element. Byfeed- 

 -ing the leguminous crops instead of ploughing them under a two-fold 

 result is secured — animals are nourished without buying expensive grain 

 feeds, and the soil is enriched to very nearly the same extent as in 

 green manuring. 



Beyond question the nitrogen of the air, which is obtained without 

 cost through the agency of leguminous plants, is best utilised in im- 

 proving the productiveness of the land and increasing the profits of 

 the farm when it is used in the production of milk and meat and 

 thereby in the production of cheap barnyard manure. What has bees, 

 said of the nitrogen applies also to the carbohydrates and fats which the 

 plant derives from the carbonic acid of the air. If the crop is fed, the 

 carbohydrates and fat serve to nourish the animal and a portion in turn 

 passes into the barnyard manure, and when applied to the soil has a 

 favourable effect on the humus formation. This is the true economy of 

 material. It is following out the law of nature. Its profitableness will 

 depend upon the price of feeding stuffs in general. The higher the 

 prevailing price of hay and other feeding stuffs the larger will be the 

 profit from feeding the crop rather than using it for green manuring. 

 Let us consider a few examples of the value of a crop for green manur- 

 ing and for feeding on different kinds of soils. 



SERRADELLA ON MEDIUM SANDY SOILS. 



Take, for instance, the case of serradella on the better "class of sandy 

 soils. This plant does well on medium light sandy soils. It may be 

 sown among win'er rye in spring. Under these conditions it produces 

 an unusually luxuriant vegetation which may either be ploughed unde 



