METHODS OF PRODUCTION 95 



One of the most valuable of all the leguminous plants 

 is lucerne, or alfalfa, and its use could be greatly developed 

 in the eastern and southern parts of England ; also I 

 believe that it will be found possible to extend its use in 

 parts of the country- where now it cannot be grown, 

 provided that varieties of seed can be discovered which 

 will stand the climate. A field can be left profitably 

 under lucerne for four or five years, and then ploughed 

 up ; it is one of the most valuable of fodder crops, and 

 one acre will provide as much food for live stock as three 

 or four acres of average grass. 



When the lucerne is ploughed up at the end of five 

 years, it will have stored up nitrogenous manure equiva- 

 lent to about one ton of nitrate of soda or sulphate of 

 ammonia, which is worth about £^2^ to-day and was 

 worth £^10 to ;^i2 before the war. 



Nitrogenous manure is the most costly of all manures 

 to give to crops ; and as the leguminous plants provide 

 it in the cheapest manner, whatever system of cropping 

 is adopted should be so devised as to make full use of 

 these plants. 



FARM-YARD MANURE 



The other substances required by the growing crops 

 are Ume, phosphate and potash. These (save the lime) 

 are all contained in farm-yard manure which, in addition 

 to containing these substances, has a valuable pliysical 

 effect on the soil ; it adds humus (or body) to the soil. 

 But the value of farm-yard manure depends largely on 

 the way in which it is kept and handled — if loosely 

 exposed to rain and aerobic action for many months, most 

 of the valuable substances, especially the nitrates, are 

 washed out. 



Unfortunately few of our farmers handle this valuable 



