IMPROVEMENT OF GRASS LAND 143 



(A. vulgaris) and various weeds, while white clover and 

 ryegrass are present in comparatively small quantities. 



3. That the only other species of grasses which are 

 occasionally abundant in these pastures are cocksfoot 

 and sheep's fescue in the better fields, Yorkshire fog 

 and tufted hair-grass in the poorer ones. 



4. That the herbage of a pasture varies botanically 

 to a considerable extent during a season, this variation 

 being, however, determined very largely by soil, situa- 

 tion, and weather. 



5. That the choicest grazing land is invariably 

 associated with soil rich in available phosphates. 



6. That on soils suitable for permanent pasture, 

 inferiority of the herbage is generally due either to 

 (i) a deficiency of available phosphates, or (2) to their 

 bad mechanical condition. 



7. That herbage of the best grazing land may be 

 twice as rich in nitrogen and phosphate as that of 

 a poor pasture, and that this large difference appears 

 to be directly determined chiefly by the proportion of 

 white clover present, and indirectly by the percentage 

 of available phosphates in the soil. 



8. That from the early part of June onwards the 

 percentage of nitrogen and phosphate in the herbage of 

 a pasture gradually decreases, while the proportion of 

 dry matter rapidly increases. 



9. That the quantity of herbage available per acre 

 for grazing depends much upon the density of the 

 herbage, and that no plants appear to be more capable of 

 producing a dense growth of herbage than white clover 

 and ryegrass, providing the soil is suitable for them. 



10. That the number of individual plants per acre 

 on the best old pastures, and necessary for the pro- 

 duction of a thick, close turf, is probably very much 

 less than is usually supposed. 



