Page 78 - Enzymes in Tropical Soils

66 Enzymes In Tropical Soils

....... Eq. 5.2

where  b is soil bulk density, M s is soil mass, V t is soil total volume. The soil bulk
-3
density of mineral soils is about 1.32 g cm . The lower the bulk density of soils
indicates the more porous soils and the more easier for water or O 2 to diffuse into
the soil system.

Table 5.4. The evolution of CO 2 as affected by the substitution of
chemical fertilizers with organic matter *.

-1
No. Treament mg CO 2 -C kg
1 Control 81
2 Organic Matter 0% 210

3 Green Manure 50% 141
4 Green Manure 75% 149
5 Green Manure 100% 154
6 Chicken Manure 50% 293
7 Chicken Manure 75% 268
8 Chicken Manure 100% 412

*Adapted from Yusnaini et al. (2007)

Total porosity of soils can be calculated by Eq.5.3 as follows (Hillel, 1980;
Singer and Munns, 1987).

....... Eq. 5.3

or
....... Eq. 5.4

where is Total Porosity, V p volume of pores, V t total volume of soil, V a volume of
soil air, V w vilume of water, and V s volume of soil solid.
Total porosity of soils can also be calculated by Eq. 5.5 as follows
(Hillel,1980).

Abdul Kadir Salam - 2014