No. 4.] SOIL FERTILITY. 129 



themselves with the leguminous plants, such as alfalfa, 

 clover, beans, peas and so on, we enter a field of knowledge 

 which has been productive of valuable practical results. 

 In order to illustrate what I mean by this statement, allow 

 me to refer to alfalfa, a crop Avhich has come to sustain 

 an increasing importance to the agriculture of New York, as 

 well as to that of man}^ other States. If you were to step 

 into the alfalia field of the New York Agricultural Experi- 

 ment Station, and dig up the root system of a single })lant, 

 you would find attached to the roots small round bodies 

 called nodules, which are characteristic not only of this plant 

 but of all other species of the leguminous family. It has 

 been found to be true that, when the roots of alfalfa plants 

 or other legumes otow in a medium devoid of certain minute 

 organisms, these nodules do not form, and the plants often 

 do not prosper ; and that the introduction of the organism 

 into such a medium causes the nodules to develop in great 

 abundance, with a corresponding improvement in the color 

 and growth of the alfalfa or other leguminous plants. The 

 presence, then, of these bodies on the roots of the legumes 

 is a sure indication as to whether the soil in which the plant 

 is growing is inhabited by the organisms Avhich somehow 

 associate themselves with the plant, and impart to it the 

 power to take up atmospheric nitrogen. It appears to be 

 true, as shown by attempts to introduce alfalfa widely 

 throughout certain States, that some soils are not fitted for 

 the production of alfalfa, api)arently in some instances 

 Ijecause they are not charged with the organisms which main- 

 tain an existence in connection with the alfalfa plant. 

 Through a process of reasoning which certainlj- is quite 

 obvious, there has arisen, in the State of New York at least, 

 a practice known as soil inoculation. The cheap and prac- 

 tical way of doing this is by transferring to a field on which 

 it is desired to grow alfalfa for the first time a (|uantity of 

 soil from some other field whcM-e alfalfa has maintained a suc- 

 cessful existence. You ask if beneficial results have followed 

 from this practice. Not always, but decidedly so in some 

 cases. For instance, the New York Agricultural Ex})eri- 

 ment Station has this year conducted some experiments on 



