6o 



SOIL CONDITIONS AND PLANT GRO WTH 



Table XV. — Effect of Nitrogenous Food Supply on the Growth of 

 Barley in Sand Cultures. Hellriegel. 



The figures are plotted in Fig 10. Similar results are ob- 

 tained on the field plots at Rothamsted (Table XVI.). 



<3 



ft. 





16 



H2 



Fig. 10. 



224 336 - 448 



M.gms. N supplied as Ca (N0^)„ 



-Effect of nitrogenous food supply on the growth of barley. 

 (Hellriegel.) 



Table XVI. — Broadbalk Wheatfield, Average Yields, Fifty-six Years, 



1852-1907. 



The increasing effects produced up to a certain point by 

 successive increments of nitrogen may be due to the circum- 

 stance that the additional nitrate not only increases the con- 



