24G AGRICULTURAL EXPERIMENT STATION. [Jan. 



ties of the essential articles of plant food, it must be the aim 

 to provide a liberal amount of those essential constituents 

 to meet these periodical wants. The well-known fact that 

 liberal mauurins; pays better than a scanty one finds its 

 explanation in the existence of the above conditions. The 

 heavier the crop the larger should be the return of the 

 constituents carried off from the soil, for that essential 

 article of plant food which is present in the soil in less 

 quantity than the growth of the plant requires controls the 

 final result. 



It has been the aim of the wTiter, since the establishment 

 of the agricultural institutions at Amherst, to furnish object 

 lessons to our i'arming community in regard to a rational 

 system of fertilization by carrying on a series of field ex- 

 periments with a variety of farm crops. 



The local conditions of the soil with reference to the 

 existing amount of plant food had to be, as far as prac- 

 ticable, determined by actual field trials before the special 

 lines of investigation could be entered upon. Our earlier 

 reports furnish abundant proof of the importance ascribed 

 to a suitable preparation of each experimental plot for the 

 special line of inquiry decided upon. 



The natural inherent resources of the soil were usually 

 ascertained by raising for several years in succession, without 

 any manurial addition from outside sources, crops requiring 

 difierent proportions of the essential articles of plant food, 

 thereby reducing the soil to its normal condition regarding 

 the amount of plant food present, as far as practicable. 



Most prominent among the experiments carried on are 

 those with relation to the eftect of a liberal supply of the 

 different forms of potash on sugar beets,* sorghum, f 

 grapes, i potatoes § and several leguminous and grain crops ;|| 



* See eighth, ninth and eleventh annual reports of the Massachusetts Agri- 

 cultural College for the years 1871, 1872 and 1874. 



t See sixteenth annual report of tlie Massachusetts Agricultural College for 

 the year 1879. 



X See thirteenth annual report of the Massachusetts Agricultural College for 

 the year 1876. 



§ For details see annual reports of the Board of Control of the Massachusetts 

 State Agricultural Experiment Station for the years 1884-93. 



II For details see annual reports of the Board of Control of the Massachusetts 

 State Agricultural Experiment Station for the years 1884-89. 



