Page 177 - Enzymes in Tropical Soils

Enzymes in Tropical Soils 165

add to the mixture. The ratio of C/N is observed until a particular value, usually 12,
is reached, indicating that the resulted compost is matured.
Therefore to make a good compost, the technique must suffice the
following conditions:

1. Organic matters must be prepared in small chuncks,
2. Microorganisms must present in the mixture,
3. Inorganic N must be enough to sustain the development of microorganisms,
4. Reaction (pH) must be maintained by lime,
5. The mixture must be moistened during the decomposition process,
6. Oxygen must be available for oxidation and CO 2 must be pumped out from the
stacks of organic residues.

There are several methods of composting. In general, the organic residues
are usually made in small chuncks. To introduce the microorganisms, cattle dung
or chicken dung at a small amount is usually added to the mixture along with Urea
to provide inorganic N and lime to maintain soil pH. The mixture is also usually
turned regularly to provide O 2 for oxidation and to pump the resulted CO 2 out of
compost. The piles can also be stacked in a particular order so that O 2 can easily
enter the mixture and the CO 2 may exit freely of the system. Water is also added
regularly to moist the mixture. By these combination, the composting process will
progress as needed and produce a good product.
What happens during the organic residue decomposition is that the
microorganisms develop and produce some enzymes. Each enzyme is effective and
specific in accelerating the transformation of an organic nutrient to an inorganic
nutrient. The addition of Urea, O 2 , and water is to make a good condition so that
the microorganisms may produce enzymes at high concentrations and may allow
the enzymes to do their roles. At the end, partially destructed organic matters are
produced with some nutrient elements have been transformed into available forms
ready for plant absorption upon application into the soil system. The organic
matters in the compost are more stable and will not give sudden effects on the soil
chemical and biological properties and reactions.

11.3 Biological Fertilizers

How to apply enzymes directly to the fields so that these substances may
catalyze the organic matter decomposition applied in the fields? This question
must be answered by biological fertilizers. Biological fertilizers may contain the

Abdul Kadir Salam - 2014