Soil Water Content, (cm3/cm3)


 .2 .4
i I < *


Wn. I I I I I1 0 1
 .8 1.0 1.2 1.4
 Soil Bulk Density, p (g/cm3)


Figure 13. Distributions of 0 and p
tural equipment (Ferraz, 26).


in a soil compacted by heavy agricul-


creased from air-dryness to 50%, the bulk density of the soil decreased
from 1.30 to 1.17 g/cm8 (fI- 12). Thus, as the soil became wet by
the infiltration, the soil was observed to swell,
 Another kind of study, possible only with the dual-energ. gamma
method is that of determining 0 and p in soils that have undergone com-
paction under field conditions due to heavy equipment such as harvest
machines and agricultural mechanization. Ferraz (26) took samples of
undisturbed Red soil (soil No. 2 in Table 4) in a sugar-cane field, using


 C
O r


20.


40.


60.


 80.


100.


120


)