XI.] MANURES FOR GRASS LAND 331 



grazing is at once improved, and as the nitrogen con- 

 sumed mostly comes back to the grass, a permanent 

 improvement sets in. Should white clover not appear 

 the season after the basic slag has been sown, it is 

 possible that the land was without the small plants 

 mentioned above, and a few pounds of white clover 

 seed should be sown and harrowed in. After this first 

 dressing of basic slag, the land will steadily improve for 

 five or six years, after which time a fresh application of 

 fertiliser is called for. By this time the soil will have 

 gained nitrogen through the growth of the white clover, 

 but it will not be wise to trust to basic slag alone for 

 the second dressing, since the land will have lost some 

 of the potash liberated by the original treatment with 

 basic slag. The second and later dressings should 

 therefore be accompanied by about 3 cwts. per acre of 

 kainit to keep the clover vigorous ; and if the land is 

 ever laid up for hay, it will be necessary to use 

 nitrogenous fertilisers pretty freely. As long as a 

 pasture containing a good proportion of white clover 

 is only grazed, it is probable that the nitrogen content 

 of the land does not fall off, but we cannot trust to 

 white clover to make good the large removal of nitrogen 

 in a hay crop. 



The thin sandy soils are more difficult to improve 

 than the clays ; basic slag exerts but little effect, partly 

 because the soil is too dry to allow it to act very freely, 

 but more because there is but little potash in the soil 

 to be liberated by the action of the lime in the basic 

 slaer. Bone meal has often been recommended for these 

 soils, remembering the improvement which bones have 

 effected upon the Cheshire pastures. Bone meal is, 

 however, too slow in its action to be profitable, and a 

 phosphate like steamed bone flour or phosphatic guano 

 will be better. About 2 to 3 cwts. of such a phosphate 



