11EL.VT1VE PROPORTION OF CORX AND STRAAV. 'J03 



but less of nitrogen and pliosplioric acid remain over 

 for the formation of seed ; the exact quantity is Hmited 

 by the total amount of transformed S^ constituents. 



The closeness of the St constituents in different soils 

 may, however, be approximately ascertained from tlie 

 relative proportion of corn and straw obtained from a 

 plot manured with phosphoric acid and nitrogen, and 

 from an uumanured plot respectively. 



If the unmanured plot yields corn and straw in the 

 proportion of 1 : 2*5, and the manured plot gives a larger 

 crop in which the corn is to the straw as 1 : 4 (straw 

 being in greater proportion), it is evident that the S^ 

 constituents preponderate in the latter field ; and a much 

 larger quantity of phosphoric acid and nitrogen would 

 have to be supplied in order that the field, correspondently 

 with its amount of S^ constituents, might produce the same 

 relative proportion of corn and straw as, for example, the 

 land at Oberbobritzsch. 



It is a very essential part of the farmer's business to 

 study the nature of his field, and to discover which of the 

 nutritive substances, useful to plants, his land contains in 

 preponderating quantity : for thus he will know how to 

 make a right selection of such plants as require for their 

 developemeut a superabundance of these constituents; and 

 he will obtain the greatest profit from his field, when he 

 knows what nutritive substances he must supply in due 

 proportion to those which are already in abundance. 



Two fields, in which the total amount of nutriment is 

 unequal, but the relative distribution of the substances is 

 the same, will produce crops differing in quantity, but 

 agreeing in the relative proportion between corn and 

 straw. 



Such a relation, for example, exists between the field 

 at Oberboljritzsch and the field at Mauscgast. If the cro[) 



