22 
TABLE 10—MINERALOGICAL AND CHEMICAL ANALYS 
Labora¬ 
tory 
Number 
Depth 
to 
Which 
Sample 
Was 
Taken 
Pounds of Total Plant Food 
Constituents per Acre 
Surface, 6 2-3 inches.... 2,000,000 lbs. 
Subsoil, 28 inches=_ 8,000,000 lbs . 
Minerals Other 
than Quartz in 
Abundant Mine 
N 
P2O5 
K 2 0 
CaO 
Sand 
Silt 
Sand 
Average 
of S sa 
mples. 
Soil 
Inches 
Percent. 
Percent. 
1193 
0-8 ] 
1207 
0-8 
1,174 
1,111 
8,287 
9,126 
33 
36 
Altered biotite, mus- 
1209 
0-8 ] 
covite, weathered 
orthoclase 
Averag 
e of S s 
amples. 
Subsoil 
Inches 
1194 
18 - 36 ] 
1208 
“ 
2,110 
7,053 
25,741 
36,065 
32 
35 
Orthoclase, biotite, 
1210 
“ J 
muscovite 
universally low in nitrogen and phosphoric acid, and in the south¬ 
eastern part of the State, also in potash. The potash content is much 
higher in the northern part of the Coastal - Plain section °, especially 
is this true north-east of Albemarle Sound. The soil of the Edge¬ 
combe Farm is between these tw r o extremes approaching the lower 
rather than the high potash content. These light sandy soils are also 
deficient in lime. This deficiency is noticeable in growing legume 
crops. Bacteriological investigations show this soil to be very deficient 
in beneficial bacterial life. 
Plats. 
The plats at the Edgecombe Farm on which the experiments were con¬ 
ducted are embraced in Fields A and B. The farm on which all the 
plats are located has been in cultivation for a good many years. 
The experiments were started on Field A in 1903 and on Field B 
in 1905. The plats in Field A were laid off in three parallel series of 
thirteen plats each with a turn row or driveway between each series. 
The plats are one-tenth acre in size, with an unfertilized space between 
them sufficient for one row and a four-foot unfertilized space at the 
end of the rows. Plats, 1, 2 and 3 of the second series and 1, 2, 3, 
4, 5, 6, 7 and 8 of the third series of this field are somewhat inferior 
in fertility naturally to the other plats of the field due to surface 
washings. 
The plats on Field B were laid off similarly to those of Field A, 
except the plats of the third series were one-twentieth acre in size. 
Another difference was that in field B provision was made for two 
rows between plats instead of one, as in Field A and these extra 
rows were fertilized like the plat nearest to them, hut were not 
