16 CHEMICAL FERTILIZERS 



" The improvement in the hay and pasture at Cockle Park, 

 especially in the quality of both, has enabled a much larger 

 stock to be kept with considerably less expenditure on con- 

 centrated feeding stuffs. The better feeding quality of the 

 hay has reduced the amount of cake and meal needed in the 

 winter, and the better feeding quality of the pasture, especially 

 of the winter f oggage, has enabled the grazing stock to depend 

 to a much greater extent on the pasture." 



At Cockle Park basic slag, superphosphate and dissolved 

 bone have all been experimented with, and, provided other 

 conditions are satisfactory, phosphatic manures, whatever 

 their nature, give somewhat similar results. The phos- 

 phatic manures used have shown an increase per acre of i, 

 as measured by the mutton produced by sheep grazing. As, 

 however, basic slag is very much cheaper than either of the 

 other two, counted in terms of the amount of phosphorus 

 supplied, it can be confidently recommended even in bleak 

 districts. The more expensive forms of the phosphorus 

 manures may yield results which are satisfactory enough, 

 but unless large increases in crop are obtained there is a 

 difficulty in making a sufficient profit to cover the cost of 

 the fertilizers. With sufficient rainfall, protection from wind 

 and good working soil such increases are frequently made, 

 but in bleak and backward districts sufficient increase 

 cannot always be obtained. Where general farming condi- 

 tions and prospects are poor, basic slag is usually preferred, 

 but with good soils and markets, superphosphate is more 

 commonly used. 



One great result of the development of root action by the 

 use of phosphatic manures is to make the soil easily penetrated, 

 not merely by roots, but also by air and water. The soil 

 then becomes the home of a large population of various 

 forms of soil life, varying in magnitude from bacteria to earth 

 worms. Experiments which have been made on the results 

 of applying certain particular forms of phosphoric acid to 

 the soil show that the pure forms of ferric phosphate, alu- 

 minium phosphate and calcium phosphate give increases of 

 crop. Superphosphates, however, produced far better 



