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The Effect Of Pesticides Dichlorodiphenyl Trichloroeyhane (d.d.y) And Benzene Hexachroride (bhc) On The Microflora Of The Three Types Of Soil
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According to Burges and Raw (1967) loamy like clay is a product of
degradation and synthesis. And the agencies responsible are the living
organisms in the soil both the animal (fauna) and the plant (flora).
These organism engineer a myriad of biochemical changes as decay takes
place. They also physically chum the soil and help stabilize soil
structure. A rast number of organism live in the soil. By far the
greater proportion of these belong to plant life. Yet animal are not to
be minimized especially in the early stage of organic decomposition.
Edward
and lofty in 1969 explain that the activities of specific group of soil
organisms are commonly identified by (a) their numbers in the soil (b)
their weight per unit volume or area of soil (biomass) and (c) their
metabolic activity. Although the relative metabolic activities are not
shown, they are generally related to biomass of the organism. As might
be expected, the numbers are highest among the micro organism. So great
are microflora number that they do minate the biomass in spite of the
minute size of each individual organisms. The microflora monopolize the
metabolic activity in soil. It is estimated that 60-80% of the total
soiil metabolism is due to the microflora.
They further said that
some of the many naturally and artificially occuring substance have
deleterious effect on the life of at least some species of organism in
the soil by inhibiting the development of these species. However, there
is continuing concern that these chemical substance may also adversary
affect various non parasitic segment of the soil microflora. These
chemical compound substance are called pesticide. Pesticides are
therefore material useful for the control nutigation of animals
detrimental to human or economy. Algaecides, deforlant and descant
herbicides plant growth regulator and fungicide are used to regulate
population of undesirable organisms which compete with or pristine crop
or namental plants. Attractant insecticides, muticides, accredits,
molluscide, nematodes, repellant and rodenticide are used principally
to reduce parasitism and trasmission in domestic animals, the loss of
crop plant, the destruction of processed food textile wood products as
well as parasitism and disease transmission to human.
Jones (1956)
and fletcher (1960) have shown the effect of different pesticide on
type, number and activities. They explain that herbicide and
insecticides can destroy soil micro organism or suppress their
activities if applied at excessive rate. But when applied at recommended
rate these chemicals reach soil concentration of more than 2 or 3 part
per million (PPm) however, some pesticide are obtained from plant and
minerals, while few other are obtained by the mixed culture of micro
organisms insecticides like pyrethin, cruelties and nicotine are
extracted from plant. Also toxin produced by bacillus thuringiesis are
active ingredient against moth and butterfly larrac. The toxins are
sometime called miracle geneâ€. DDt is an out standing example of
insecticide and probably the most commonly used pesticide.
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ABSRACT - [ Total Page(s): 1 ]The effect of pesticides, chchlorodipheny trichloroethane (DDY) and Benzene hexaxhoride (BHc) on the microflora of the three types of soil (loamy, clay and sandy soil) was conducted. The serial dietitian technique was employed up to 10-3 using nutrient agar, potato dextrose agar and sabourand agar plates. The isolation of both bacterial and fungal organisms were made before treating the soil types with the two pesticides), D.D.T and BHC. and after treating the soil types with D.D.T after t ... Continue reading---
