Page 98 - Enzymes in Tropical Soils

86 Enzymes In Tropical Soils

lowers the respiration by soil microorganisms. The resulted decreases in the
populations and activities of soil microorganisms then decrease the production of
soil enzymes. In the case of soil temperature, the declining pattern is suggested to
be influenced by the enzyme denaturation or the decrease in the activity of soil
organisms at temperature higher than the maximum value.
The close relationship between the soil water contents and soil temperature
is due to the fact that water molecules posses relatively high heat capacity. This
property enables water to resist the increase in temperature with heat impact.
Therefore, daily, monthly, and yearly fluctuations in soil temperatute are controlled
by soil water content. Soils with high water contents will encounter lower
fluctuation in temperature than those with lower water content. This
phenomenon is hypothetically depicted in Fig. 6.1.

40
35
Temperature ( o C) 30 Low Water

25
Content
20

Content
15 High Water
10
18 22 2 6 10 14 18
Time

Fig. 6.1. The influence of soil water content on the soil
temperature fluctuation (Salam, 2012).

Fig. 6.1 clearly shows that the soil water content and soil temperature are
very closely related. It infers that we can manage the soil temperature by
regulating the soil water content.

Abdul Kadir Salam - 2014