TESTING THE NEEDS OF THE SOIL 157 



the acid phosphate. And there are soils still plentifully supplied with phos- 

 phoric acid which are deficient in potash and nitrogen, so that by providing 

 nitrogen through legumes he need buy only potash. On the coast of North 

 Carolina, intelligent farmers assert that phosphoric acid gives no good 

 results on their cotton crop, while nitrogen and potash are very important. 

 On the other hand, in the upper districts of the South, in Georgia and 

 Northern Texas, potash is found of little importance, while phosphoric acid 

 is the governing factor in all fertilizer mixtures. On the lower Mississippi, 

 the river has evidently brought down plenty of potash, and the sugar planters 

 do not need it. On the other hand, in New England generally potash is a 

 leading deficiency. It will usually be found that in the upland red clay 

 soils', along the eastern side of the Blue Ridge mountains, potash is little 

 needed, while, as a rule, on the sandy soils of the Atlantic seaboard, potash 

 is the most important constituent of a fertilizer. Prof. Voorhees states that 

 in -New Jersey, on good loamy soils, potash and^ phosphoric acid are of far 

 more importance in the fertilizers for the corn crop than nitrogen; while 

 on the sandy soils, nitrogen and potash are relatively of more importance 

 than phosphoric acid. This agrees with experiments on similar sandy soils 

 in Eastern North Carolina. 



On land devoid of humus and in a low state of productiveness, it is 

 safe to say that in the start of the improvement, a complete fertilizer con- 

 taining a due percentage of each of the three important elements, is the 

 thing to apply; while, as we accumulate humus and nitrogen through the 

 use of leguminous crops, we can by degrees get rid of the necessity for the 

 purchase of nitrogen, and it may be found that one of the other constituents 

 is present in abundance and that the want of productiveness^ag^ot due to 

 the lack of it. 



