CROP ROTATIONS 189 



(9) A well planned rotation may result in a better 

 distribution of labor. At present our labor require- 

 ments at harvest time are large and at other seasons of 

 the year small. Until some modification of our present 

 system of cropping is made, this difficulty will increase 

 rather than diminish. The use of more crops might dis- 

 tribute the harvest season from the last week in June 

 to October whereas now the grain crop harvest is practi 

 cally confined to the six weeks between August 15th and 

 the end of September. If biennial or perennial crops are 

 grown instead of some of the annuals, the acreage to be 

 prepared each year is less, the seed may often be sown 

 with a grain crop, the period of harvesting is pro- 

 longed, and the stock may aid in harvesting, thus lessen- 

 ing the labor required. Some provision for winter work 

 must also be made if this problem is not to be a perman- 

 ent one. What work will ultimately be provided is not 

 clear, but some form of live stock enterprise seems the 

 most promising. 



(10) Continuous cropping is reported to result in 

 the development of poisonous substances in the soil. 

 Recent investigations have been interpreted as showing 

 that when one crop is grown continuously on a piece of 

 land, the soil becomes toxic or more or less poisonous to 

 that particular crop. It is offered in explanation that 

 the roots give off substances which are poisonous to the 

 plants. It is stated that these substances are not poison- 

 ous to other kinds of crops and that by changing from 

 one crop to another the ill effects are not found. 



147. Requirements of Rotations in Western Canada. — 



Under our present system of farming not only is the risk 



of partial failure very great but the organic matter of 



^ the soil is decreasing, soil drifting is increasing, plant 



