Page 79 - Enzymes in Tropical Soils

Enzymes in Tropical Soils 67

= 1 - b/s ....... Eq. 5.5

where is the total porosty of soils,  b is the soil bulk density, and  s is the soil
particle density. The values of ranges between 0 – 1 or 0 – 100%. The total
-3
pososity of sandy soils with bulk density of 1.5 – 1.7 g cm ranges between 0.43 –
0.36 or 43 – 36%. The total pososity of clay soil with bulk density of 1.1 – 1.3 g cm -
3
ranges from 58-51%.

The soil particle density ( s ) is the total soil mass divided by the volume of soil solid,
can be calculated by Eq. 5.6 as follows (Hillel, 1980; Singer and Munns, 1987).

....... Eq. 5.6

With  s is the soil particle density, M t the total soil mass, and V s the volume of soil
solids (Fig. 5.2).

V t

V s V p

SOIL SOLIDS SOIL PORES

M s

Fig. 5.2. The relationship between soil particle and bulk densities
(Salam, 2012).

Abdul Kadir Salam - 2014