CROP ROTATIONS 



209 



manently maintain productiveness without live stock, 

 not only is a good rotation necessary but also the use 

 of commercial fertilizers. In systems of live stock 

 farming when all the crop residues, such as straw and 

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

 ductiveness may be maintained for an indefinitely longer 

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

 clude legume crops an'd commercial fertilizers. Yet even 

 live stotek farming is not a permanent system, except 

 when butter and n'otlhting else is sold! from the farm. 



Tig. 75. Cattle Wintering Outside, Protected only by the Trees. 

 Courtesy Man. Dept. of Agr. 



Unfortunately the most permanent system is not al- 

 ways the best for immediate results. The farmer natur- 

 ally and perhaps legitimately considers that system best 

 which gives the most profit at the present time. The 

 problem of the future lies in finding for each soil and 

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

 able and the most permanent. 



167. General Conclusions Regarding Rotations. No 

 permanent profitable rotations have yet established 

 themselves in this country. It is probable that in addi- 

 tion to the money crops ordinarily grown, the fallow, 



