170 



Farmyard Manure. 



[JUNE, 



Table XIII. — Total Produce per acre of Barley Plots, showing 



Residual Effects of Dung. 



Dung 

 Every 

 Year, 

 since 

 1852. 



Dung for ' 



20 Years, Unmanured 

 1852-71, Continu- 

 Unmanured ously. 

 Since. 



Plot 7-2. Plot 7~i, Plot 1-0. 



Relation to Produce of 

 Plot 7-2, reckoned as 100. 



Plot 7-2. Plot 7-1. Plot 1-0 



Mean, 1852-1871 

 1872 

 i873 

 1874 

 1^75 

 1876 



1877-1881 

 1882-1886 

 1 887-1891 

 1892-1896 

 1 897- 1 90 1 

 1 902- 1 906 



Lb. 



Lb. 



Lb. 



Lb. 



Lb. 



Lb. 



5,933 



2,454 



100 



4 I 



5,202 



4,870 



1,282 



100 



94 



25 



6,561 



5,i65 



i,57o 



100 



79 



24 



7,943 



5,675 



1,922 

 1,448 



100 



7i 



24 



5,825 



3,955 



100 



68 



25 



6,166 



4,010 



1,561 



100 



65 



25 



6,167 



3,305 



1,528 



100 



54 



25 



6,546 



3,494 



1,529 



100 



53 



23 



5,334 



2,664 



i,379 

 1,508 



100 



5o 



26 



6,477 



3,ioi 



100 



48 



23 



5,349 



2,251 

 2,485 



1,141 



100 



42 



21 



6,223 



1,301 



100 



40 



21 



the Rothamsted mangold crops for the years 1900 and 1907, 

 when crops considerably above the average were grown, and 

 compare the yields obtained when farmyard manure was used 

 alone and in conjunction with nitrate of soda, with that given 

 by a purely artificial dressing containing nitrate of soda. 



Table XIV,- 



■Yield of Mangolds at Rothamsted, 1900 and 1907, 

 Roots only. 



Year. 



Farmyard 

 Manure = 

 200 lb. N. + 

 Phosphoric Acid 

 and Potash. 



Phosphoric Acid 

 and Potash 

 + Nitrate of 



Soda = 86 lb. N. 



Farmyard 

 Manure = 

 200 lb. N, + 

 Nitrate of Soda 

 = 86 lb. N. 



Farmyard 

 Manure = 

 200 lb. N. + 

 Phosphoric 

 Acid and Potash 



+ Nitrate of 

 Soda = 86 lb. N. 





' 



Tons. 



Tons. 



Tons. 



Tons. 



1900 



28-0 



33-i 



4i'3 



41-8 



1907 



26*5 



32-8 



41-4 



42-1 



The farmyard manure, though it contained about 200 lb. 

 of nitrogen, could not provide the rapidly-growing mangolds 

 with as much nitrogen as did the nitrate of soda containing 

 86 lb. of nitrogen, since it only grew 27-2 tons of mangolds 

 against 33 tons with nitrate of soda, and this notwithstanding 



