CROP ROTATIONS 209 



nanently maintain productiveness without live stock, 

 lot only is a good rotation necessary but also the use 

 )f commercial fertilizers. In systems of live stock 

 'arming when all the crop residues, such as straw and 

 itubble and manure are returned to the land, soil pro- 

 luctiveness may be maintained for an indefinitely longer 

 ime than in systems of grain growing that do not in- 

 Audie legume crops and' coimmeroiial fertrliizers. Yet even 

 ive stoick fanning is' not a permanent system, except 

 vhen butter and notlhiing else is soldi from the farm. 



rig. 75. — Cattle Wintering Outside, Protected only by the Trees. 

 • — Courtesy Man. Dept. of Agr. 



Unfortunately the most permanent system is not al- 

 vays the best for immediate results. The farmer natur- 

 illy and perhaps legitimately considers that system best 

 vhich gives the most profit at the present time. The 

 problem of the future lies in finding for each soil and 

 ilimatic zone the system that is at once the most profit- 

 ible and the most permanent. 



167. General Conclusions Regarding Rotations. — No 

 permanent profitable rotations have yet established 

 ;hemselves in this country. It is probable that in addi- 

 iion to the money crops ordinarily grown, the fallow, 



