258 CARE OF GRASS LANDS. 



must infer, the climate and situation have much to do in helping 

 solve the question whether to keep land permanently in grass, or 

 whether to include the grass in a rotation of crops. 



At the present day, even in England, some of the most 

 advanced farmers favor breaking up the dryer arable land, and 

 believe in this way they can obtain the largest yield of animal 

 food. 



In favorable climates, land which will permanently support a 

 good growth of grass must be naturally of the very best quality, 

 in good heart, well prepared, and afterwards liberally manured 

 for some years. 



There are a few excellent farms in Southern Michigan, in Ohio, 

 Kentucky, Wisconsin, and neighboring States, which contain 

 permanent pasture of good quality, and which yield liberally. 

 Generally the grass does not continue uniform. It dies out or 

 becomes thin in some places, and vacancies are filled with grasses 

 of poorer quality, or with weeds of no value. 



In Johnson's Affricultural Chemistry ^xq read: " It is pretty 

 generally acknowledged that land laid down to grasses for one, 

 two, three, or more years is in some degree rested or recruited, 

 and that it diminishes in value again after two, three, or jBve 

 years, more or less, unless some manure be given to them. The 

 opinion is due largely to the annual production of roots (and 

 rootstocks) on old grass land, which is equal to one-third or one- 

 fourth of the weight of hay carried ofC. '' 



The roots of grasses extend deeper than is generally supposed. 

 These with the stubble, old leaves, and turf, make a large 

 amount of vegetable matter. Mr. Lawes estimates that on a 

 good pasture they will weigh from five to ten tons per acre of dry 

 matter, containing accumulated nitrogen to the extent of one 

 ton. 



In rather dry climates, where the rootstocks and roots of an 

 old pasture have formed a mat of vegetable materials, the yield 



