320 SOILS AND SOIL PROCESSES. lo. 



of graffes and other plants ; forming a tough 

 mat of fibres-, reaching, in feme cafes, feveral 

 inches deep ; efpecially over a cold moifl: 

 fubfoil ; where the fedgy tribe are frequently 

 in full pofTefTion, 



If the foil be THIN, it is wholly occupied by 

 roots : the bottoms of the furrows afford Jio 

 locfe mould for covering the feed j which 

 either lies cxpofed on the furface, or falls 

 through the feam.s upon an infertile fubfoil, 

 and among grafs, ftill perhaps in a growing 

 ftate. The few grains which happen to get 

 buried in the mould flourifli while their own 

 fubftance lafts ; but the kernel being cx- 

 haufted, the rootlings look out in vain for 

 foreign fuftenance -, the foil is already occu- 

 pied by veteran roots too powerful for the 

 infant fibrils to contend with. 



But if the foil be deeper than the 

 SWARD, the feeds get properly covered, and 

 the young plants have frelli mould to Ibike 

 root in ; and to fupport them until the fward 

 die, decay, and afford nourifhment to the 

 rifing crop. 



The USES OF SOD-BURNING thick-fwardcd 

 foils are thofc of effe^flually killivg ike fivard% 



doing 



