194 



The Rothamsted Grass Experiments. 



FATE OF THE NITKOGEN IN THE SOIL. 



It has already been shown what large quantities of nitrogen 

 were supplied to the farmyard manure plots in the experi- 

 ments upon permanent meadow land, and how little became 

 recovered in the crop. Does this large amount of un- 

 recovered supplied nitrogen remain in the soil, and in such 

 a condition of combination and distribution as to be avail- 

 able to succeeding crops ? Or may not some of it be lost 

 by drainage, or in other ways, and the remainder become so 

 locked up or distributed as to be so slowly recoverable, if 

 ever, that it can be reckoned of scarcely appreciable practical 

 value ? 



TABLE XLVIII. ESTIMATED AMOUNT OF DRY SOIL PER ACRE AT EACH 

 DEPTH; NITROGEN PER CENT. IN THE DRY SOILS, AND ESTIMATED 

 NITROGEN PER ACRE, AT EACH DEPTH. 



Samples of the soils of all the experimental grass plots 

 were taken in February and March, 1876, that is, after the 

 experiments had been in progress twenty years, and before 



