LEGUMINOUS CHOPS. 



115 



in either of the cereals, the root-crops, or potatoes, grown 

 under similar conditions. 



Thus, as the bottom line of the upper division shows, there 

 was an average over the 32 years, of 24.8 lb. of nitrogen 

 per acre per annum in the crops without any manure, but of 

 35.4 lb. with the mineral manure without nitrogen ; whilst 

 the amount was raised to only 42.4 lb. by the addition of 

 nitrogenous manure. Over the first 8 years, however, the 

 yield was very much higher, being for the three plots re- 

 spectively 48.4, 60.2, and 69.0 lb. Over the second period 

 of 8 years the average was not far from that of the whole 

 32 years, but over the third and fourth periods it was much 

 less. 



TABLE 36. — Beans. Yield op Nitrogen, average per acre 



PER ANNUM, LB. 8-YEAR PERIODS. 



Yields of 

 nitrogen 

 without 

 manure, 

 with min- 

 eral man- 

 ure, and 

 with nitro- 

 genous 

 manure. 



Total produce (corn and straw). 



Unnianured. 



Mixed 



mineral 



manure 



(including 



potash). 



Mixed 

 mineral 

 manure 



and 

 nitrogen. 



Average per acre per annum, over each 8 years, and over the 32 years. 



Average per acre per annum, over the years of crop only, each period. 



1st 8 years, 8 crops 

 2nd 8 years, 7 crops 

 3rd 8 years, 7 crops 

 4th 8 years, 4 crops 



32 years, 1847-78, 26 crops . 



48.4 

 28.9 

 10.4 

 32.7 



30.5 



60.23 

 39.2 

 26.8 

 53.3 



43.9* 



69.0 

 42.1 

 40.0 

 57.4 



52.2 



1 7 years, excluding 1849, in which year the produce was accidentally not weighed. 



2 31 years, excluding 1849. 3 7 crops, excluding 1849. 

 4 25 crops, excluding 1849. 



As in the case of the total produce itself, so also in that of 

 the nitrogen in the total produce, if we take the averages of 

 the years of crop only, as given in the bottom division of the 

 table, we have a much higher average yield per annum over 

 the 4 years of crop of the last 8 years, than over the years of 



