TO TURN GRASS LAND INTO ARABLE. 265 



the green crop. Burning- produces, too, n liig'lilv fertilizing- 

 manure, comiiosed ot" a mixture of ashes, burnt soil, and 

 charred vegetable matter, impregnated with alkaline salts, 

 which are known to be powerful jjroraoters of vegetation. 

 Generally speaking, land which is selected to be broken up 

 is covered with a large r|uantity of coarse grass, furze, briars, 

 blackthorns, straggling heath-})lants, rest-harrow, sedge, 

 rushes, and many other coarse and woody-stemmed plants, 

 which could not be made to decompose with suiiicient 

 rajudity without burning. By burning, and especially stifle- 

 burning, the roots, fibres, and stems of pl-ants become 

 charred, and are de}n-ived of that tenacity which binds the 

 sods together in matted masses. 



The modes proposed for tilling each kind of land after 

 being converted into arable, will in a great measure be indi- 

 cated by the succession of crops named in our estimates. 

 But the nature of the soil of our island is almost as variable 

 as the rocks on which it rests, and therefore the rotations 

 which I have named can only be applicable to a limited 

 extent. Thev cannot be strictly api)licable to all soils, nor 

 to the same soil in difl'erent circumstances. There are ex- 

 ceptions to all rotations arising from situation, climate, soil, 

 population ; and, therefore, I dare not ])resume to offer them 

 as applicable under all conditions. They are only indices of 

 that system which may be successfully applied on soils 

 having characteristics in common with those which we have 

 mentioned. Even on the soils possessing those general cha- 

 racteristics, the crops may be ver}' much varied from those 

 which we have named. Thus it may occasionally be best 

 to sow oats instead of barley, and beans, and other green 

 crops, on a portion of the land which I have assigned for 

 seeds, and many other changes may arise from circum- 

 stances, which will cause the farmer, indeed compel him, to 

 deviate from those systems; but if he adhere to the one 

 grand point of following the white crops with green crops, 

 ■whatever system he may adopt will have nearly the same 

 result as those proposed. 



On thin light calcareous or gravelly soils, sainfoin will 

 answer better than seeds, and therefore should be substi- 

 tuted. The strong fibrous roots of sainfoin operate on the 

 thin loose soils of calcareous rocks, like the arund'tnacerp, on 

 the sands on the sea-coast, in imparting cohesion to the soil. 

 Sainfoin also produces, by the time it is worn out, a tough 

 sward, full of vegetable matters, which by paring and burn- 



