1921.] 



It is clear that phosphates are the foundation of all improve- 



ment of pasture in this country. Their effect is now well known 

 amongst farmers. They stimulate the clovers and other 

 Leifuminosce. A season or two after the application of basic 

 slag, a poor pasture is commonly found to be a carpet of clover. 

 Leguminous plants are nitrogen-collectors, and the result is that 

 the soil is enriched and the grasses in turn are nourished to a 

 new luxuriance. The improvement is continued in the increase 

 of the better pasture grasses, and the suppression of coarser and 

 inferior plants, whether gi'asses or weeds. 



Of the phosphatic manures, slag has proved superior to super- 

 phosphate or dissolved bones. Professor Somerville is of opinion 

 that precipitated phosphate and raw mineral phosphates ground 

 very fine are worth trying. Much of our poorer pasture land is 

 sour or acid, and the growth of clovers is stunted. Their 

 development, as has been shown, is an essential step in the 

 advance towards improvement. On account of its alkaline char- 

 acter, slag tends to counteract soil acidity, w^hereas superphos- 

 phate is acid and therefore likely to intensify the trouble. 

 Superphosphate with lime is often mentioned as an alternative 

 to slag. They have been tested side by side. In the first nine 

 years of the Cockle Park tests the total liveweight increases 

 resulting from the two dressings approximated very closely, 

 but the net gain each year, after the manures had been paid for, 

 showed a bigger balance from the plot treated with slag. 



Lime alone does not appear to be an important agent in the 

 improvement of all pastures. At three centres, as widely apart 

 as Northumberland, Northamptonshire and Hampshire, its use 

 alone continued to show a loss even after eight years. Its 

 value is on pastures wdth a tough fibrous top, which it breaks 

 down, and so prepares the way for phosphates. The condition 

 of such pastures may be due to situation or may result from 

 unsuitable manuring. Potash seems to be necessary in only 

 very few instances, but nitrogen applied in any form is n^ist 

 unsuitable. One way in which nitrogen may thus be brought 

 to the pasture is in feeding cake to the stock. Prof» spor 

 Somerville shows that cake alone gives a disappointing return 

 both directly in the liveweight increases due to its use, and 

 indirectly when an improvement conserjuent on the manurial 

 residues is looked for. With regard to caking stock on slagged 

 pasture he says: " The worst possible conditions for the use 

 of cake are when it is supplied to animals grazing land which 

 itself has been improved by slag." 



F 



