Under the head Lolium perenne I observed the practice of sowing clovers
and that grass with a crop of barley or oats, which is intended as an
intermediate crop for a season or two, and then the land to be again
broken up and used for arable crops. And this is a common and useful
practice; for although neither the Clover or Rye-grass will last long,
yet both will be found to produce a good crop whilst the land will bear
it, or until it is overpowered by the natural weeds of the ground
[Footnote: It is not an uncommon opinion amongst farmers, that Rye-grass
produces Couch; and this is not extraordinary; for, if the land is at
all furnished with this weed, it receives great encouragement under this
mode of culture.], which renders it necessary to the farmer to break it
up.

I am aware of the difficulty of persuading persons (farmers in
particular) to adopt any new systems; and I have often, when speaking of
this subject amongst men of enlightened understandings, been told it
would be next to madness, to sacrifice the benefit of a crop of oats or
barley when the land is in fine tilth, and whilst we can grow grass
seeds underneath it.

"To this I reply, that there is no land whatever, when left for a few
months in a state of rest, but will produce naturally some kind of
herbage, good and bad; and thus we find the industry of man excited, and
the application of the hoe and the weeder continually among all our
crops, this being essential to their welfare. I cannot help, therefore,
observing how extremely absurd it is to endeavour to form clean and good
pasturage under a crop hat gives as much protection to every noxious
weed as to the young grass itself. Weeds are of two descriptions, and
each requires a very different mode of extermination: thus, if annual,