THE PBINCIPLES OF MANUBING 

 PER ACRE. 



185 



nearly as bad as a deficiency. When farmers speak of a 

 soil as being "too rich," they generally mean that it 

 contains too much nitrogen. Under these conditions 

 corn crops tend to run more to straw than grain and to 

 lie down, grass becomes rank and coarse, and root crops 

 ripen before they are fully developed. These effects can 

 be, at least partially, mitigated by increasing the pro- 

 portions of the other constituents, especially phosphates 

 and potash, even though the soil may not be judged 

 by ordinary standards deficient in these ingredients. 

 The requirements of the soil must therefore be gauged 

 not wholly by the absolute quantities of the constituents 

 but, to some extent, also by the relative quantities. 



DETERMINATION OF THE MANURIAL REQUIREMENTS OF 

 A SOIL. 



Eight-plot Test. Farmers who have cultivated a piece of 

 land for some years can generally tell what are its prin- 

 cipal manurial requirements and what is the most suitable 

 form of manure to apply. If there be any room for doubt 

 it should be made the subject cf special investigation, and 

 it is better to proceed on definite systematic lines, so as 

 to settle the matter in a single season, than to try 



