( @) 
hence it follows, that the practice becomes objee- 
tionable on the score of apense, and the more so, as 
burnt clay has no possible advantage over the much 
cheaper substances of sand, gravel and pounded 
lime-stone. The operation of all is merely me- 
chanical, and exactly in proportion to the quantity 
used. | 
Our partiality for green crops, ploughed into the 
ground as manure, has been sufliciently indicated, 
and itis now only. necessary, that we mention the 
plants best calculated for this purpose. At the head 
‘of these we place buckwheat, as well on account of 
cheapness as effect : cheapness, because the price of the 
seed (which is the only additional expense) is below 
consideration ; and effect, because this plant, while 
growing, (from its umbrageous form) is a great im- 
prover of the soil, both by stifling weeds and pfe- 
venting evaporation; and when ploughed. into. the 
ground, none decomposes more rapidly, nor has any 
a more powerful effect in keeping the earth loose 
and open to the action of light, heat, air and mois- 
ture, all of which are indispensible to vegetation.— 
“I know no plant, (says Rozier, the great French 
agriculturist,) that furnishes a better manure, or 
which is sooner reduced to vegetable mould, than 
buckwheat. When cultivated with this view, the 
usual quantity of seed ought to be increased, and 
the time of sowing hastened, so as to enable you to 
have two crops of manure the same season, and Je- 
fore the sowing of wheat. 
The dupin (one of the leguminous family) has been 
long and profitably employed as a manure in Spain, 
