Anniversary Address. 433 



From this knowledge we have obtained of the soil's inability 

 to conserve for plant use the constituent nitrogen (upon 

 which its fertility so much depends) in the same way as it is 

 able to keep safe such mineral constituents as potash 

 and phosphorus, we have learned — that while there is no 

 necessity to apply any excess of these latter, over and above 

 what is actually removed of them by the crop — it is ab- 

 solutely necessary, in order to maintain the fertility of the 

 soil and obtain the best results, to apply a large excess of 

 nitrogenous dressings, over and above what the crop is 

 found actually to remove. This is peculiarly the case as 

 regards the manuring required for all the cereal crops and 

 the grasses, but not for turnips, clovers, and the leguminosse. 

 These latter seem to have some peculiar powers of assimi- 

 lating nitrogen, nay, even of assisting in its manufacture 

 within the soil, which the former have not, and about which 

 there is still much to learn, and much most interesting 

 discussion and investigation going on at the present time, 

 involving the part which micro-organisms and bacteria? may 

 probably have to do in the nitrification of soils. 



Then as regards the different crops of the farm, we have 

 learned their different specific wants and their different 

 powers of assimilating these under different circumstances 

 of soil and climate, and at different stages of their growth. 

 Accordingly it is the practice to use for turnips, principally 

 phosphatic dressings, more or less soluble according to the 

 nature of the soil, the season of application, and the climate; 

 for leguminous crops, principally potassic dressings ; and for 

 the graminese, principally nitrogenous. As to farm-yard 

 manure, its intelligent preparation, conservation and 

 application is now pretty thoroughly understood ; and 

 accordingly the practice, in all these particulars, varies very 

 much from that of thirty years ago. Feeding stuffs, rich in 

 their manurial residual value, are much more largely used 

 in butcher meat production — covered-in courts are pretty 

 general on all farms — and the dung so prepared is commonly 

 applied directly to the land from the courts, and immediate- 

 ly spread. Farm -yard dung is also now very largely used 



