148 AGRICULTURAL SURVEY OF chap. nf. 



cope with its more powerful enemies, often pinr 

 ed away and perished. 



To cure this evil as speedily and as effectually 

 as possible, recourse was had to summer-fallow- 

 ing, and the remedy, wherever it has been ju- 

 diciously applied, has been attended with com- 

 plete success. By frequent ploughing and har- 

 rowing, all the seeds of the weeds are brought 

 alternately Jo the surface, where they are allow- 

 ed to spring, and then turned down and des- 

 troyed. All the roots, too** of perennial weeds 

 are torn up and separated from the soil, and are 

 either gathered together and burnt, or carried 

 off the ground. 



But cleaning land, though a principal., is not 

 the only advantage obtained by fallowing. It 

 is useful, also, to enrich the soil, to break and 

 reduce it, when too hard and stiff, and to keep 

 it longer from tiring of any particular rotation 

 of crops. By frequent ploughing and harrow- 

 ing, a considerable quantity of vegetable sub- 

 stance is not only produced, but immediately 

 reduced to a state of putrefaction, and thus con- 

 verted into manure. The land is also broken 

 and pulverized, and consequently fitted to re- 

 ceive and retain, more readily, the fertilizing 

 dews and showers of rain. And the ground 

 being opened, becomes more penetrable by the 

 air, which, as it circulates through innumerable 

 pores, deposits- in the soil the putrid effluvia 

 which it collects and carries along with it, as it 

 passes over the surface of the earth. Hence we 

 find, that if land under a course of fallowing 

 be opened up, even in the driest weather, it will 

 appear black artd moist. But if ground, that 



