306 MEADOWS AND PASTURES 



than on Plot l v the unmanured plot. Plot 7, however, continuously 

 dressed with slag and kainit, but no nitrogen, for the same period, 

 has now about 5 per cent more soil nitrogen in the surface 6" of 

 soil than in the same of the unmanured plot, and has also produced 

 more than double the weight of hay. From the analysis of the hay 

 it has been calculated that the hay removed annually from Plot 7 

 contained 18 pounds more nitrogen per acre than that removed from 

 Plot 1, or as much nitrogen in 13 years as is contained in 13^5 

 cwt. nitrate of soda. There is also an increase of .005 per cent 

 nitrogen in the surface 6" of soil of Plot 7 over that of Plot 1, 

 which represents about 75 pounds of nitrogen an acre, the equiv- 

 alent of nearly 5 cwt. of nitrate of soda. The slag and potash on 

 Plot 7, therefore, have indirectly provided as much nitrogen per 

 acre during the 13 years as is contained in about 18 cwt. of nitrate 

 of soda, and this only takes into account the surface 6" of soil. 

 Here is, therefore, an excellent demonstration of how mineral 

 manures (slag and kainit) may indirectly make use of nitrogen from 

 the air by developing clovers and other leguminous plants. The 

 amount of phosphates applied in the slag is double of that in the 

 superphosphate; but in each case the quantity applied is probably 

 about the right quantity for giving the best results. The lessons to 

 be derived from these thorough and long-continued experiments 

 on the manuring of old land hay are: 



"On the heavier soils phosphatic manures are by far the most im- 

 portant, and of these basic slag is on the whole the most satisfac- 

 tory. On the lighter soils basic slag alone is not likely to be effec- 

 tive, but when accompanied by a potash manure, excellent results 

 are usually given. Too heavy dressings of superphosphate may do 

 considerable harm on some soils. It will be seen when the results 

 of several years are taken into account that neither nitrate of soda 

 nor sulphate of ammonia is a desirable manure for old land hay. 

 The weight of the crop will probably, in the long run, be less, while 

 the quality will undoubtedly be poorer. This applies either to these 

 manures used by themselves, or in combination with phosphates and 

 potash. Slag only (on the heavier soils) or slag and a potash 

 manure say muriate of potash or kainit usually develop clover 

 and allied plants in a marked degree, and small annual dressings 

 of these will* continue this development of clover herbage, as is 

 shown by many of the experiments. On the whole, neither ground 

 lime nor common lime has given anything like profitable returns, 



