132 



EFFECTS ON ACID AND SANDY BOILS. 



corn, leaving two years of rest in four. This soil was lighter than 

 the subject of any preceding experiment, except the 9th. On a 

 high level part, surrounded by land apparently equal, a square of 

 about an acre (A) was staked off, and left without marl which 

 that year's work brought to two sides of the square (C, D, and E). 



B 



Results, 1820. In corn. October 18th, three half acres of marled 

 land were measured, and as many on that not marled, and close ad- 

 joining, and produced as follows : 



Not marled. 

 Bush. 



Half acre in A, 7 

 The same in A, 7 

 Half acre in B, 7 



Marled. 



Pecks. Bush. Pecks. 



1 adjoining in C, 12 3 

 1 " D, 13 3f 



2J " E, 15 



The average increase being 12 J bushels of grain to the acre, 

 nearly 100 per cent, as measured, and more than 100 if the defect- 

 ive filling, and less matured state of the corn not marled, be con- 

 sidered. The whole would have lost more by shrinkage than is 

 usual from equal products. 



1821. The whole in wheat ; much hurt by the wetness of the 

 season. The marled part more than twice as good as that left out. 



1822 and 1823. At rest. A good cover of carrot weeds and 

 other kinds had succeeded the former growth of poverty grass and 

 sorrel, and every appearance promised additional increase to the 

 next cultivated crop. November, 1823, when the next ploughing 

 was commenced, the soil was found to be evidently deeper, of a 

 darker colour, and firmer, yet more friable. The two-horse ploughs 

 with difficulty (increased by the cover of weeds) could cut the re- 

 quired depth of five inches, and the slice crumbled as it fell from 

 the mould-board. But as the furrows passed into the part not 

 marled, an immediate change was seen, and even felt by the 

 ploughman, as the cutting was so much more easy, that care was 

 necessary to prevent the plough running too deep ; and the slices 

 turned over in flakes, smooth and sleek from the mould-board, like 

 land too wet for ploughing, which however was not the case. The 

 marling of the field was completed at the same rate (800 bushels), 



