576 
Journal of Agricultural Research 
Vol. V, No. 13 
for the first 6 % inches, which is considerably higher than the average 
for the soils of the State. Field experiments which have been conducted 
on this series for the past five years indicate that phosphorus is in no 
way the limiting element in crop production. 
The Granville soils, which are found in limited areas in the Piedmont 
Plateau, are formed from sandstone and shale. These soils are unusually 
high carriers of potassium, which is supplied mainly as microcline and 
orthoclase. While some biotite and muscovite are encountered, very 
little of the potassium must come from this source. It would be inter¬ 
esting to have field data on the requirements of the soils of this series 
for potassium, for comparison with those of the Mountain province, 
in which mica predominates. 
The Georgeville soils represent those formed from Carolina slate, and 
the minerals other than quartz are mainly the potash feldspars and those 
of a highly refractory character. Many of the particles carry an infil¬ 
tration of iron oxid, which makes identification quite difficult. Much of 
the orthoclase and biotite is badly altered, while other particles of these 
minerals are found in an unusually fresh condition, which indicates that 
an admixture of the material which enters into the formation of this soil 
has taken place. 
The soils of the Atlantic Coastal Plain are characterized by their low 
content of other minerals than quartz. The Norfolk and Portsmouth 
series are by far the prevailing soils of this province, and, with few 
exceptions, no particular mineral other than quartz predominates. 
It might be said in passing that a few instances occur in which the other 
minerals than quartz will run higher, but this is unusual. 
The average among the sand particles for the Norfolk series will not 
exceed 5 per cent of minerals other than quartz, of which none pre¬ 
dominate, Among the particles the size of silt will be found orthoclase 
residues, microcline predominating. The less abundant minerals are 
composed mainly of a heterogeneous mixture of the more refractory 
minerals found in the provinces of higher topography. A point of interest 
is the scarcity of the micas in the series; they are encountered often, but 
the quantity found is usually so small that they can be of little value 
in maintaining the potash content of the soil solution. Apatite and the 
plagioclase feldspars are rarely found, as they have passed out of existence 
during the formation of this soil. 
The Portsmouth soils are quite similar to the Norfolk, the only dis¬ 
tinctive difference being in the amount of organic matter found in the 
former. On account of their location, which is usually in submerged 
or recently drained areas, an accumulation of vegetable matter is en¬ 
countered. The average content of minerals other than quartz in this 
series is even lower than that of the Norfolk, being 3 per cent. The 
persistence of sponge spicules or Rhizopoda casts in this series is rather 
