Resource Manual on Integrated Production and Pest ... - julitoaligaen

<strong>Resource</strong> <strong>Manual</strong> on IPPM in Rice
World Education Philippines, Inc.
The amount of lime needed to raise soil pH to
a neutral status depends on the type of soil and
on the initial pH. Table 1 presents a rough
guide to raising soil pH.
I. Role of Soil Organic Matter
1. Soil Organic Matter (SOM)
When the nutrients, enter the living organisms, they tend
to circulate, moving through a food web where they are
eaten by other organisms. For example, nutrients initially
absorbed by plants might be eaten by a herbivore, which
in turn might be eaten by a predator, and so on. At each
trophic level or feeding level, energy and nutrients can
be transferred in only a few ways: a certain fraction of the
original plant or animal is passed on to the next trophic
level, or returned to the soil – either directly, or in the
form of waste products from digestion. Meanwhile, in
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Table 4. Lime Requirement for Specific pH
L im e
pH T / h a
4 . 0 1 0 . 2 4
4 . 1 9 . 7 6
4 . 2 9 . 2 8
4 . 3 8 . 8 2
4 . 4 8 . 3 4
4 . 5 7 . 8 7
4 . 6 7 . 3 9
4 . 7 6 . 9 1
4 . 8 6 . 4 5
4 . 9 5 . 9 8
5 . 0 5 . 4 9
5 . 1 5 . 0 2
5 . 2 4 . 5 4
5 . 3 4 . 0 8
5 . 4 3 . 6 0
5 . 5 3 . 1 2
5 . 6 2 . 6 5
5 . 7 2 . 1 7
5 . 8 1 . 6 9
5 . 9 1 . 2 3
6 . 0 0 . 7 5
the case of energy, all organisms respire (breathe) and when this happens, the energy
in the form of heat and carbon dioxide (CO2) is lost or goes to the atmosphere.
Eventually, every living thing dies and goes back to the soil unless the nutrients are
physically removed from the system just like what happens with products after
harvest. What happens in this process is important for farmers because the soil
organic matter (SOM) plays critical role in the functioning of the ecosystem, and in
the health of the soil and crops.