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The negative
effect of monoculture was recently demonstrated
in rice production. Here herbicides had been recommended for use in the
paddy
fields; but instead of herbicides ducks were introduced. The ducks ate
the
weeds and the insects and increased the yield of the paddy. As the
young ducks
were also fed at night they essentially brought some fertilizer to the
paddy in
the form of faeces. Now fish have also been introduced to consume the
plankton
grown in the paddy fields as a result of the ducks fertilizing the
paddy. The
total income per ha increased by 50 times.
[1]
Inter-Cropping coconut gardens with vegetables, pulses, tuber crops,
fruit
crops such as banana and pineapple makes for sustainable farming,
according to
Dr. V. Rajagopal, Director, Central Plantation Crops Research Institute
(CPCRI), Kasargod, Kerala.
"Usually farmers prefer to grow a variety of intercrops in the coconut
gardens as growing coconut alone as a monocrop is not viable, as
farmers have
to wait a minimum of four years (in the case of dwarf varieties) to
realise a
good profit," he said. Growing vegetable and banana between the coconut
trees can supplement income in the developing stages of the coconut
palms,
according to Rajagopal. "Also the leaves of vegetables and banana can
be
effectively used as a green mulching material for the coconut palms to
enhance
nut productivity", Rajgopal from Kerala said.
Mr. Maniyani, a model farmer who is practising the concept of coconut
based
intercropping for higher income has effectively utilised the interspace
in his
coconut garden for raising different vegetable and pulses as
intercrops. In his
0.88 hectares, Mr. Maniyani grows local west coast tall coconut variety
as the
main crop. There are about 110 coconut palms out of which 75 are in
bearing.
This coconut variety "is well adapted to the local climate of Kerala
and
the average yield of the tree is about 80 nuts every year," said Dr.
Rajagopal. By adopting intensive intercropping with crops such as
banana,
tapioca, cowpea and bhindi (lady's finger/okra) in his coconut garden,
Mr Maniyani
has been able to get a net income of Rs.10,000 -12,000 every year. [2]
Therefore,
intercropping system of agriculture saves space.
In a well-planned inter-cropping system early established plants tend
to reduce
soil temperature and produce the appropriate microclimate for other
plants.
Plants also complement each other in terms of nutrient cycling, thus
deep-rooted plants can act as 'nutrient pumps' bringing up minerals
from deep
down in the sub-soil. Minerals released by the decomposition of annuals
are taken
up by perennials. The high nutrient demands of some plants are
compensated for
by the addition of organic matter to the soil by others. Thus cereals
benefit
by being grown in conjunction with legumes, which have deeper roots,
permitting
a better use of nutrients and soil moisture as well as possessing root
nodules,
which host bacteria, specialized in fixing nitrogen.
[3]
In coastal Kerala, rice cultivation is alternated with prawn farming.
The
method requires no fertilizers or pesticides. Most farmers in the
saline
coastal tracts of Ernakulam, Thrissur and Alappuzha districts of
central Kerala
alternate pokkali cultivation with prawn farming. These marshy tracts
are close
to the Arabian Sea, and
saline
water floods the fields regularly. The high and low tides affect water
and
salinity levels. In normal course, soil acidity and high salinity would
inhibit
rice cultivation. "But pokkali is resistant to salinity, flood and soil
acidity," points out V Sreekumar, associate professor, Rice Research
Centre at Vyttila, Kochi.
Many farmers in area aren't too keen on it. [4]
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