96 SOILS AND FERTILIZERS 



soil. Where live stock is kept, the manure judiciously 

 used, and the crops systematically rotated, the crop- 

 producing power of the land is not decreased, as in the 

 case of the one-crop system. The influence of differ- 

 ent systems of farming upon the humus content and 

 other properties of the soil may be observed in the 

 following table : 3I 



S-8 



bee 





Character of soil. ^p^ Sp, 01 PL,O,C&. 



Cultivated thirty-five years ; 

 rotation of crops and ma- 

 nure ; high state of pro- 

 ductiveness 70 3.32 0.30 0.04 48 



Originally same as i ; con- 

 tinuous grain cropping for 

 thirty-five years ; low state 

 of productiveness 72 1.80 0.16 o.oi 39 



Cultivated forty-two years ; 

 systematic rotation and 

 manure ; good state of pro- 

 ductiveness 70 3.46 0.26 0.03 59 



Originally same as 3 ; culti- 

 vated thirty-five years ; no 

 systematic rotation or ma- 

 nure ; medium state of 

 productiveness 67 2.45 0.21 0.03 57 



