NITRIFICATION IN ARABLE SOIL. 501 



The most important part of the cultivation of the soil is done in Octo- 

 ber or iSfovember. The soil broken uj) by the plow and rendered 

 absorbent stores up the rain water of winter, which would flow oft" the 

 surface of a soil hardened by dryness or compacted by rain. The first 

 cultivation is very well performed by the plow, but this implement does 

 not do more than to turn over the sod without breaking it, and arrange 

 it in parallel strips. There is no pulverization, and this is an advantage 

 if the soil is to remain uncovered during the winter, since pulverization 

 promotes an active nitrification, which is very undesirable under these 

 conditions, the nitrates formed in a soil without vegetation being irre- 

 vocably lost. 



When the time of seeding approaches, however, as thorough jmlver- 

 ization as possible is desirable. The harrows and cultivators which 

 are commonly used do not answer the inirpose, since they stir the soil 

 very imperfectly. Our efftjrts should be directed toward improving 

 these implements in this respect. The advantage of perfect cultivation 

 in the soil is seen among the French peasants. They cultivate their 

 fields again and again in different ways, and without knowing it pro- 

 mote a very active nitrification. Cultivators of sugar beets know that 

 the weight of roots harvested increases with the number of cultivations 

 to which the crop is subjected. 



From the earliest times cultivation of the soil has been considered as 

 labor jjar excellence. The man who performs it is known as " the 

 laborer." Slowly and laboriously through the ages he has perfected his 

 implements. From the piece of wood hardened in the fire and drawn 

 by an ass he has passed to the iilow drawn by oxen or the more power- 

 ful implement driven by steam. But further efforts are still necessary 

 in order to utilize the immense reserves of the soil. The plow is the 

 emblem of agriculture only until we are able to find a better. The soil 

 is a niggardly mother who distrusts her wasteful children and refuses 

 at first to give up her treasure, but yields finally to the supreme force 

 of the world — work. 



