ix.] RECLAMATION OF FEN LAND 259 



The fire was never allowed to burn too fiercely, the 

 object being to obtain charred residues rather than 

 white ashes. The effect of burning the peat was to 

 provide a certain amount of ash rich in saline matters 

 and particularly in alkaline carbonates, thus correcting 

 the two great faults of the remaining peat, its deficiency 

 in mineral matters, and its sour reaction. At the same 

 time the weeds and other coarse vegetation occupying 

 the surface were destroyed, and a clean seed-bed prepared 

 for the crop. However, the process of burning is a 

 very wasteful one, involving the loss of the combined 

 nitrogen contained in the accumulated organic matter, 

 and after a few repetitions the land was found to be 

 seriously depleted of its reserves of humus. Burning 

 became replaced in the Fens by a marling process, 

 especially where the peat was of a sandy nature ; trenches 

 were opened to the bed of marl or clay always found 

 beneath the peat, and the clay thrown out and spread 

 at the rate of 100 loads or so per acre, the burning 

 process being reserved for the first reclamation, when 

 a mass of surface vegetation had to be got rid of. In 

 other districts, where marl is less available, peat has 

 to be brought into cultivation by draining the land with 

 open cuts, allowing some considerable time to elapse 

 during which the peat dries, shrinks, and consolidates, 

 and then correcting the acidity with lime. It is desir- 

 able to use large dressings of mineral manures like 

 basic slag and kainit to compensate for the deficiency 

 in mineral matter, especially where the peat is initially 

 of an acid character. In the Fens the peat is some- 

 times found to be mild humus containing lime ; this 

 does not respond to liming, and gives better crops with 

 superphosphate than with basic slag. 



