THE FIRST AND FUXDAMEXTAL PPJXCTPLE IX AGRICULTURE. 7 



the experiments extend over twenty-four years, in two periods 

 of twelve years each. At the top of the last period stands the 

 unmanured plot with a diminished produce of six bushels per 

 acre below the first period; the next experiment is with 

 400 lbs. superphosphate continuously, and the diminished 

 produce is over seven bushels per acre ; next 400 lbs. mixed 

 minerals, and the produce has diminished seven bushels ; next 

 800 lbs. superphosphate and mixed minerals, and the produce 

 has diminished nine bushels ; next 200 lbs. ammonia salts and 

 400 lbs. superphosphate = 600 lbs., and the produce has dimi- 

 nished two bushels ; next 600 lbs. ammonia salts and mixed 

 minerals, and the diminished produce is four bushels ; next 

 200 lbs. ammonia salts and 800 lbs. superphosphate and mixed 

 minerals = 1000 lbs., diminished produce three bushels; next 

 275 lbs. nitrate of soda, diminished produce seven bushels ; and 

 farther down the list of these experiments there are larger 

 applications of these manures ; but all shov/ that the crops have 

 diminished more or less, w^ith the single exception of the farm- 

 yard dung, which is of course w^holly made up of vegetable 

 matter in a forward state of decomposition, and thereby the 

 fertility and value of the land has been upheld. 



But, were these experiments tested by profit and loss, as they 

 must be before they can establish a right or wrong principle, I 

 fear that no farmer could then follow the example. But the 

 diminished produce, as shown by this table, does not show the 

 full diminution over the twenty-four years. This table only 

 shows the average of the second twelve years compared with the 

 average of the iirst twelve years. Were we in a position to 

 deduct the produce of the twenty -fourth year from the produce 

 of the^^rs^ year, probably the diminution over the whole experi- 

 ments in this table would average about eight bushels per acre. 

 The diminished value of the land in this instance in twenty-four 

 years by continuous cropping would thus be the value of eight 

 bushels barley per acre ; and, valued at thirty-five shillings per 

 acre, capitalised at twenty-five years' purchase, is equal to 

 £43, 15s. per acre. This looks like a good reason for the dis- 

 tre.ss in the agricultural districts of England. At all events it 

 shows that, as vegetable matter decreases in the soil, so does the 

 produce per acre ; and on an average the unmanured plot has 

 not diminished so much as the manured plots. This table of 

 experiments is specially valuable in demonstrating tliat no other 

 manure will uphold the fertility of the soil under continuous 

 cropping but vegetable matter; and that the produce of the 

 manured plots have been largely fed off the lost fertility of the 

 soil, namely at the rate of 36s. 6d. annually at twenty-five 

 years' purchase, or if taken at thirty years' purchase, the annual 

 loss would be 43s. ()d. Therefore, if the value of the lost 

 fertilitv drawn from the soil was added to the cost of the 



