46 THE GRASSES 



suited to certain soils, but wholy unsuited to others. It 

 was also well known, though by no means so generally, 

 that certain manures stimulated the growth of certain 

 grasses and seemed to retard the growth of others. Chemi- 

 cal analysis disclosed that the soils that were suited to dif- 

 ferent grasses were composed of different ingredients, or if 

 containing the same ingredients, they were present in 

 different proportions. Also analysis showed that the grasses 

 that nourished on a given soil were composed largely of 

 the plant food that characterized that soil, and on the other 

 hand that a grass that ran out quickly on a given soil con- 

 tained a large amount of some ingredient in which the soil 

 was deficient. 



From these facts it seems but an easy step to infer that 

 certain manures might be relied on to stimulate the growth 

 of certain grasses ; yet simple and easy as the step seems it 

 was not taken with anything like assurance until those dis- 

 tinguished experimenters, Lawes and Gilbert, of Rotham- 

 sted, England, demonstrated by a series of field experiments 

 continued through several years, that the character of the 

 herbage in different parts of any given pasture or meadow 

 in^ay be entirely changed by the continued and abundant 

 use of different manures. The reports of these experiments 

 were made to the Royal Agricultural Society of England, 

 and are to be found in the journals of that society from 

 1858 to 1865. The general results of these experiments 

 may be briefly summarized as follows : 



I. Mineral Manures, (super-phosphate of lime, sulphate 

 of soda, sulphate of magnesia), stimulated the growth of 

 the leguminous plants, (clovers), but scarcely affected the 

 natural grasses. 



II. Nitrogenous manures, (guano and ammonical salts), 

 stimulated the natural grasses and discouraged the legumi- 

 nous herbage. 



