SECRETARY'S REPORT. 265 



School, and at a price whicli exhausts very considerably the appro- 

 priation. Hence the necessity of delaying the experiments and im- 

 provements originally designed by the Board, and of raising only 

 such products and in such quantities as were required for the use 

 of the institution, as the only means of meeting the expenses of the 



year. 



While your committee have kept constantly in mind the wants of 



the institution, they have endeavored, so far as the means placed in 

 their hands would admit, to make trial of such fertilizers as could 

 readily be obtained, with a view not only of supplying the deficiency 

 of stable manure, but at the same time to test their adaptation to cer- 

 tain crops, their comparative value, and in some instances, their dura- 

 bility and effect on a similar crop on the same soil for a series of 

 years. 



The nature and constitution of soils, their origin and diversity of 

 character, and the causes of their productiveness, are subjects not 

 well understood, and require deep and thorough investigations. 

 If we knew what fertilizers would best promote the growth of crops, 

 and what kind and quantity must be given to each particular crop, 

 we should be possessed of the most important secret in profitable 

 cultivation. Unfortunately, we do not often possess this most essen- 

 tial information and frequently administer manures Avhich are abso- 

 lutely unsuited to the wants of the plant. There are, hoAvever, 

 elements in virgin soil which give the first crops a luxuriance seldom 

 obtained in subsequent harvests. Chemists inform us that this 

 can be maintained for a succession of years, and have undertaken 

 to define not only the constituents of soils and crops, but to prescribe 

 the necessary fertilizers for each particular crop, — that where the 

 soil is deficient, or deprived of them, as upon exhausted fields, 

 they can be supplied, and the fertility not only maintained but 

 increased. It has therefore been a matter of the first importance 

 to test this theory, become acquainted Avith the eff"ects of the vari- 



If, 



ous fertilizers in use, the best methods of application, and to ascer- 

 tain whether by any system of special manuring we can restore to the 

 soil the elements which have been carried off in the crops. 



The rapid increase in the price and consumption of guano, super- 

 phosphates and other concentrated manures in this country, and the 

 thousands of acres of exhausted lands in the Middle and Southern 

 States Avhich have been made fertile by their application, has con- 

 firmed the theory of special manuring, and awakened a general inter- 

 est among the cultivators to ascertain their real merits as economical 

 fertilizers. This should not excite surprise Avhen Ave consider that 



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