i 4 CHEMICAL FERTILIZERS 



is used the turf smells foul, but with basic slag and potassium 

 chloride a sweet-smelling turf is formed. 



Equally striking results are shown on land which is grazed. 

 On the unmanured plot, yellow clay still remains close to the 

 surface,yet on the plot that has been manured for over twenty 

 years with basic slag a very useful loam soil extends 10 ins. 

 or 1 2 ins. from the surface . The steady downward trend of the 

 roots and the fibrous loam appears to be still continuing. 

 Dressings of phosphates are particularly valuable where 

 greater root development is required. They are not quite so 

 much needed on sands, because great root formation takes 

 place on these soils in any case. In a particular corner at 

 Palace Leas, where the soil happened to be somewhat sandy, 

 the marked differences alluded to above are not so easy to 

 observe. In addition to what has been said above, phosphates 

 are used with great effect on all root crops, such as swedes, 

 turnips, potatoes and mangolds, and they are also found 

 necessary for the growth of barley. They have been found 

 especially valuable where droughty conditions are experienced. 

 In India it has been discovered that phosphates can be made 

 to save irrigation water, and in New Zealand the application 

 of phosphates, even of the most insoluble kinds, has produced 

 marked and valuable results. Phosphates, moreover, pro- 

 mote early ripeness and shorten the period of growth ; they 

 are extremely valuable for accelerating the ripening of crops 

 in districts and climates where there is ordinarily much risk 

 of loss by persistent bad weather. The most northern 

 limit to which wheat production in Canada can be pushed is 

 partly dependent upon the supply of phosphates, and, given 

 ample supplies, there is little doubt that the limit of wheat 

 cultivation could be pushed still further north. It has 

 always been noticed at Rothamsted that the barley plots 

 that have been manured with phosphates are ripe while the 

 others are still green. In spite of what has been said above 

 of the extraordinary value of the phosphates, the results are 

 not as striking as those shown by nitrogen compounds. 

 There is not such an obvious change in the appearance of 

 the plant grown with a full supply of phosphates as there is 



