cellent covering crop, and, like most tap,rooted plants, 
does not exhaust; bat on the contrary increases fer- 
tility. I have known a good crop of wheat, follow the 
ploughing in a luxuriant vegetation of young, succulent 
teazle and thistles;—tap rooted plants. These appa- 
rent pests had for several years occupied the field. They 
had. operated as a cover, and, when ploughed in, asa 
green manure. 
The lot on which I first strewed plaister, twenty-five 
years ago, has not been ploughed during that period. 
Ihave twice given it about half a top dressing of stable 
dung. I have repeated the plaister three or four times ; 
three, four and six bushels to the acre, at intervals of 
three, four and five years. I should have preferred 
ploughing, had it been convenient, as, in the second 
crops, I am often tormented with Indian grass and 
weeds. But the ground is on a part of my farm, where 
the hay and pasture are more useful to me, than any 
other crops. After dressing with dung, I have left a 
part unplaistered, to compare it with the rest; and al- 
ways perceived a striking inferiority, where the plaister 
was not strewed. I once repeated the plaister on a part 
of it, without previously dunging, after it had been 
mowed several years, from the time it was first plais- 
tered. The plaister seemed to have no effect. But on 
applying a slight dressing of dung the next year, this 
part was equally good with the rest./s) This lot is 
(s)I have notwithstanding this instance, frequently plais- 
tered here and in other parts 0: my farm, and succeeded well » 
without dung; but never in the degree I have perceived 
3 
