1903.] 



PUBLIC DOCUMENT — No. 33. 



137 



Potatoes (Bushels pek Acre). 



Results of the Addition 

 TO Nothing of — 



Complete 

 Fertilizer. 



Plaster. 



Uulimed : — 

 Merchantable, 

 Small, . 



Limed : — 

 Merchantable, 

 Small, . 



—2.5 



—7.6 



—6.6 

 —4.6 



Value of increase, unlimed. 

 Value of decrease, unlimed, 

 Financial result, unlimed, 



Value of increase, limed, 

 Value of decrease, limed, 

 Financial result, limed, . 



$46.64 



27.44 gain 

 50.68 



31.48 gain 



$3.02 

 6.62 loss 



8.48 loss 



It will be noticed that no plot in the field has produced 

 what is regarded as a good crop. This field has now been 

 tilled for several years without the introduction of a grass 

 crop, and the stock of humus in the soil must be exceedingly 

 small. It is believed that this deficiency in humus, on the 

 presence of which, in moderate quantity, potatoes are known 

 to l)e quite dependent, accounts in a measure for the rela- 

 tively low yield on the plot to which a complete fertilizer 

 was applied. It will be noticed, further, that there is not a 

 very wide difference between the yields of the unlimed and 

 limed portions of the several plots. With onions as a crop the 

 difference is very large on all plots to which nnuiate of 

 potash, nitrate of soda, or both of these fertilizers without 

 dissolved bone-black are applied. The fact that potatoes 

 show a far smaller difference may be due to either of two 

 causes : first, that this crop is less sensitive to a deficiency 

 of lime than onions ; or, second, that the effects of the lime 

 applied in 1898 are now largely exhausted. We have some 

 evidence that this effect is so exhausted. The soil on the 

 limed portion of the plots manured with muriate of potash 

 or nitrate of soda, as shown by chemical tests, appears to be 

 once more acid. 



