58o 



Journal of Agricultural Research 



Vol. V, No. 13 



Lime has not given material gains with cotton in either test, owing 

 undoubtedly to the physical condition of this land and the large amount 

 of lime carried by the two soils. As a general rule, the minerals which 

 carry lime in the Piedmont soils are more susceptible to chemical and 

 physical decomposition than those found among the fields of the Atlantic 

 Coastal Plain. 



Table V gives the average yield of cotton on Norfolk fine sandy loam 

 at the Edgecombe Substation with seven years' fertilization. 



Table V. — Average yield of cotton on fields A and B with seven years' fertilization at 

 the Edgecombe Substation 



Table V gives the results of fertilizer tests which are in marked con- 

 trast to those obtained from the Cecil series of the Piedmont Plateau. 

 Fertilizer mixtures carrying potash give the most marked yields; in 

 fact, nitrogen and potash give greater returns than the three fertilizer 

 constituents. 



Lime in connection with the three fertilizer elements has produced 

 decided gains. The physical condition of this soil is surely as good as 

 that of the Cecil sandy loam at Raleigh, and the amount carried by the 

 soil is quite sufficient to furnish this constituent as a plant food for a 

 number of years to come. The petrographic examination of the Norfolk 

 soils gives epidote as the only lime-bearing mineral of any consequence. 

 It would seem therefore that lime carried in this form is of doubtful value 

 in performing its functions in the soil. 



The amount of potash here is even greater than that found in the 

 sandy loam at Raleigh, yet potash seems to be the limiting element on 

 this field. Weathered orthoclase and microcline furnish practically all 

 the potash supply of this soil, while biotite and muscovite micas are 

 much more abundant in the Cecil series. 



Another interesting point brought out in these experiments is in 

 regard to the phosphoric-acid content of the three fields. In the Edge- 



