CiiM'i Ki; V 



FAU'h III.\(i llli: SOIL — FAIi'M K'RSOrROES 



1. Wliilt /■urn/ UrsoiO'ii s Air 



lO.'). Tbr real fertility iA' tli.- laii<l is its 

 |Mi\Vfr to product' n-ops. It is soiiit'tiiiit's sai<l 

 to be the riehiiess of tlie soil in t'lniieiits ol 

 plant - food ; Imt soils witli iiiiicli j)la?it-f()(Ml 

 may still Ih' improdiu'tivt-. i'^•rtility is pro- 

 ductive powci". It is the I'csult of i,'ood jihysi- 

 cal condition and an ahuiidancc of available 

 plant -foo(l. 



1<| i. \Vf have found (in ('lia))tcrs ii., iii. 

 and iv.) that the first step towards increasing 

 the productiveness of soil is to improve its 

 physical texture. This impn^vement is accom- 

 plished both by mechanical means, as tilhiire 

 and draiiuiETe, -and by the addition of hunnis. 

 The humus results from the applieation or incor- 

 poratioii of organic matter. 



107. We have seen (.'U) that humus is 

 supplied, in praetieo, by eropping. — that is, \)\ 

 veixetable matter left on the ground after the 

 crop is removed, r.r by crops plowed under 



(77) 



