TABLE I. 



Wheat grown for forty years in succession on the same land, Broadbalk 

 Field, Rothdmsted. Results showing the effects of exJiaustion, and of 

 manure-residue. Quantities per acre. Produce Dressed Grain in 

 bushels. 



Mineral Manure " 



alone blue; 

 Ammonium Salts 

 alone (86 Ibs. Nitro- 

 gen) yellow; 

 Min. & Amm. Salts, 



Mixed 

 Min.Manr 

 Am. Salts. 

 172 Ibs. N. 

 13 years, 

 1852-'64. 

 Unman'd 

 since. 



14 Tons 

 Farm 

 Yard 



Manure, 

 every 

 year. 



Mixed Mineral 

 Manure alone, 



blue; 



Ammonium Salts 

 alone=86 Ibs. Nitro- 

 gen, yellow; 

 alternately. 



Without! Mixed 

 Manure Mineral 



green; 

 CTnmanured white 



Bushels 

 20% 

 32 

 27 X 

 29% 



S* 



Bushels. Busnela. 



Harvests. 

 1844 

 1845 

 1846 

 1847 

 1848 

 1849 

 1850 

 1851 



8 yrs. '44-'51 



1852 

 1853 

 1854 

 1855 



1868 



1869 

 1870 



1871 



1872 

 1873 

 1874 

 1875 



1876 

 1877 

 1878 

 1879 



1880 

 1881 



1HS-J 



(1) Average of 5 years, 18601864, inclusive. 

 (3) Average of 5 years, 18601864, inclusive. 

 (5) Average of 13 years, 18521864, inclusive. 



(2) Average of 3 years. 1865 1867, inclusive. 

 (4) Average of 11 years, 18651875, inclusive. 

 (6) Average of 19 years, 1865 1883, inclusive. 



