CHAPTER V. 



PULVERIZATION. 



A CRUMBLING COXSISTENCY OF SOILS NECESSARY THE IMPORTANCE 



OF PULVERIZATION STIFFNESS OF CLATS THE NON-RETENTION OF 



SANDY SOILS COLDNESS OF HEAVY EARTHS SUMMERS INJURIOUS 



EFFECTS OF DROUGHT EXAMPLE OF PROPER VALUATION OF ARABLE 



SOIL THEORY OF JETHRO TULL EFFECT OF INSECTS UPON PUL- 

 VERIZATION DEPTH DIGGING CIRCLES AROUND TREES DEPRECATED 



POWER OF EXTENSION BY ROOTS DEEP CULTIVATION AFFORDS 



FRESH EARTH MANNER OF OPERATION THE SEASON RESULTS 



OF it: RAPID ABSORPTION OP MOISTURE FREE ADMISSION OF THE 



AIR THE MIXTURE OF EARTHS THE DESTRUCTION OF INSECTS — 



THE INCREASE OF HEAT. 



CR-UMBLING consistence of the soil is a ne- 

 cessary quality to the perfection of its fertility. 

 A tenacious clay is unproductive because it is stiff, 

 and it is therefore rendered an unsuitable pasture 

 for the roots of plants. Being solid, it resists the 

 attempt of the spongioles to extend themselves for 

 food ; and even though there be an abundance of 

 pabulum present, still, as they cannot reach it, it is 

 as useless to the economy of plant life as though 

 it did not exist. This tenacity of the soil prevents 

 the air from penetrating and warming it, and also 

 prevents the decomposition of manurial substances. 

 It absorbs too much moisture, and holds it in a 



