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| AGRICULTURE TRIBUNE |
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ORGANIC
Smart farmer gets the worm Killing pests sans chemicals
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ORGANIC The cumbersome technical aspects of organic farming
notwithstanding, it has generated considerable interest in the farming
community in Punjab and neighbouring states. In the South, it has
already started establishing roots. Though on a small scale, a number
of farmers on their own are engaged in organic farming. Now the Punjab
Agri Export Corporation has come forward with a programme to make this
variety of agriculture popular in the state, which has been trying to
diversify to give a new meaning to the Green Revolution. The
corporation has chalked out a programme to launch organic farming in
the state officially from the next Kharif season. From the response
that has been generated by this effort of the corporation, it appears
that farmers would turn up in large numbers to adopt organic farming
in spite of the fact that this is highly technical and requires
specific knowledge to achieve success. In the past one week, about
300 farmers have registered with the corporation to seek consultancy
to start organic farming. Mr Kirpa Shankar Saroj, a senior officer of
the corporation, says, "Of course, it is a new area for the
farming community to venture into, but Punjabi farmers are known for
handling difficult jobs with ease". Before going in for organic
farming, the corporation has made careful studies in this connection.
It has got its officers trained in this field in Maharashtra and
elsewhere. Moreover, consultancy firms would be roped in to extend a
helping hand to farmers interested in organic farming. "We would
play the role of facilitators only. The job would be handled by
consultancy firms," says Mr Saroj.
The concept In
general terms, producing food without using chemicals in the form of
fertilisers and pesticides is known as organic farming. It is
difficult because one has to work hard to grow food without using such
chemicals in a state like Punjab, where entire farming is dependent on
heavy doses of chemicals such as fertilisers and pesticides. According
to an estimate, pesticides worth Rs 1,000 crore were used in the
cotton crop alone in the state. It takes four years for a farmer to
free his land and crop completely of inorganic material after stopping
the use of chemicals as nutrients and crop savers. There are
accredited agencies that certify food produced by farmers as organic
and free from any trace of chemicals.
Challenges In
Punjab, there is no place where crops are grown in isolation. Paddy,
wheat and even vegetables are grown in vast stretches spread over
miles and miles. Because of this factor, it becomes difficult for
farmers to start organic farming, as their neighbour may not
cooperate. Neighbours’ cooperation is required as pesticides and
fertilisers used by them can affect the organic crop of a farmer
engaged in this job. To protect organic crops from pesticides that
may be used in the neighbourhood, one has to raise at least 20m-high
wind barriers. This raises the cost of production. And it is very
difficult to stop chemicals from seeping into organic fields from the
neighbourhood through water used for irrigation. Another challenge
is that Punjab farmers are an impatient lot. They work on a
year-to-year basis and cannot wait for four years for certification.
The fact is that in organic farming one has to be very patient.
Big
demand Mr Manmohan Pal Singh Sidhu, a Muktsar-based farmer, who
earlier served as Managing Director of Assam Tea Company, says the
future of organic farming is very bright. "I have been doing
organic farming for the past few years and my experience is
encouraging," he says. "I am ready to extend a helping hand
to all those interested in this field." He suggests that Punjab
farmers should adopt organic farming on a large scale. There is a
high demand for organic foodgrains in Europe and other countries. The
entire northern hemisphere is covered by snow in winter, forcing
people there to import fresh vegetables from Israel and other
countries. India, especially Punjab, where agro-climatic conditions
are most suitable for organic farming, could become a big export zone
targeting such countries. There is a $25 billion market for organic
foodgrains in the world at the moment. And it is growing. People in a
few countries even want to wear clothes made from organic cotton. Mr
Sidhu says there is a debate among farmers in this region on whether
they should go in for organic farming or not. Allaying their fears, he
says they have certain wrong impressions, such as decline in
production and marketing hassles. "But I can say with authority
that the farmers venturing into this field would ultimately be earning
much more than their counterparts engaged in conventional
farming". There is no problem of marketing. There are traders who
are ready to pick up the produce right from the field, he adds. |
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Smart farmer gets the worm Degradation of organic waste using earthworms is one
of the recent developments in biological sciences. Earthworms break
down complex organic residues into simpler water-soluble substances.
In the biodegradation process, earthworms and microbes work together
and produce vermicompost. The species of earthworms that are being
used for compost production are Eisenia foetida, Eudrilus
eugeniae, Perionyx excavatus, Lumbricus rubellus and
Pheretima elongata. Earthworms degrade all types of organic
waste, such as agricultural waste, animal droppings, weeds, industrial
effluents, forest leaf litter, etc. Plants and herbs that are
insecticidal or aromatic should be avoided. Residues rich in lignin,
like stalk of woody plants, take relatively more time to degrade.
Rich
in nutrients Vermicompost is rich in plant nutrients. It provides
vital macro elements such as N, P, K, Ca, Mg and micro elements such
as Fe, Zn, Cu, etc. Apart from this, it contains plant
growth-promoting substances such as NAA, cytokinins, gibberalins, etc.
It also harbours beneficial microflora. Worms also have the capacity
to store heavy metals and pesticides in their tissues. Thus, to a
certain extent, they play a role in detoxifying polluted soils,
too.
Technique Pit method: In the initial stage, go
for a bed of size of 10x1x0.3 m. The beds should be treated with
chlorpyriphos @ 2ml/litre of water to prevent ant and termite problem.
After 15 days, fill the beds in layers with organic residues as
explained: First layer—decomposable plant material (bottom of bed);
second layer—cowdung/ farm manure/ biogas sludge; third layer—spread
earthworms (1000-2000 in number); fourth layer—cowdung/ farm manure/
biogas sludge; fifth layer—dry crop residue/ green succulent leafy
material, plus cowdung; sixth layer—thick layer of mulch with cereal
straw (top of bed). Each layer, except the third, should be 3-4-inch
thick, so that the bed material is raised above the ground level.
Sufficient dry and green wastes should be used. The mulch at the top
prevents loss of moisture and acts as a barrier to predators like
birds. The beds should be in shade. Heap method: In this
method, composting is done on the ground without the pits. Organic
material is piled up on the ground, as in the pit method, the only
difference is that the heap gets a dome shape. The suitable size for a
heap is 10x1x0.6 m. Wooden box or brick column: Here
rectangular wooden or brick structures (3x1x1 m) are erected above the
ground level and the organic material is dumped inside serially as in
earlier methods. These beds have to be watered regularly to maintain
a moisture level of 60-80 per cent till the harvest of compost. Multiplication
of earthworms: Earthworms are bisexual, but cross-fertilisation is
the mode of reproduction. Adult worms, 15-21 days after copulation,
lay cocoons, which look like coriander seeds. The eggs present inside
the cocoon hatch into neonates in about 15-21 days. Neonates take
35-60 days to attain adulthood, which is characterised by a swollen
band near the anterior part of the body. Eudrilus eugeniae, one
of the species used for vermicomposting, completes its lifecycle in
about 65-80 days. It lays 400 plus cocoons in about 60 days. Vermicomposting
can be tested from a small collection of pellets on the top of the
beds around 45-60 days after start. This is indicative of good
multiplication of worms in the beds. In about 60 days, the material is
degraded completely and vermicompost is ready for harvesting. The
rate of degradation depends on the loading of worms. More the worms,
faster the degradation. The heap method, however, has proved to be
more effective than the pit system. Harvesting: After 60-70
days, the beds are ready for harvest. Seven days prior to harvesting,
watering of the beds has to be stopped so that the earthworms in the
top layers move down for want of moisture. The beds should be
disturbed and the material collected in pyramidal heaps for about 24
hours. The semidried compost from the top of the bed can be collected
and sieved to remove any inert material. The concentrated vermiculture
(earthworms) that remains at the bottom can be used again for
vermicomposting. The compost can be dried in shade (12 hours), bagged
and stored. About 3 tonne of vermicompost can be harvested in two
months from 10 beds of 10x1x0.6 m each. Natural enemies: The
important natural enemies of vermiculture are ants, termites,
flatworm, centipedes, rats, pigs, birds, etc. Preventive measures
include treating of the site with insecticide chlorpyriphos 20 EC @ 2
ml/ 1litre or mixing of neem cakes @ 30 g/ 1kg food while filling the
beds. Rainy and winter season favour faster multiplication of worms
than summer. With manipulation of soil temperature during summer by
providing shade and regular watering, the rate can be enhanced.
Scope In
several experiments, results have indicated that vermicomposting can
substitute inorganic fertiliser requirement up to 50-75 per cent when
applied @ 10 t/ha. Vermiculture can be adopted in two ways: by
applying vermicompost @2.5-5.0 t/ha at the time of sowing or in-situ
vermiculture, wherein earthworms are directly employed in irrigated
crop fields. In case of horticulture, vermicompost can be applied at
the time of planting and subsequently at regular intervals, depending
on the age of the tree. In-situ vermiculture can be adopted in case of
young as well as grown-up trees by releasing requisite number of
earthworms at the tree basin or furrow, where adequate organic waste
has to be previously dumped. In-situ vermiculture is gaining
significance in irrigated horticulture crops. Earthworms are
introduced in situ @ 50,000-2 lakh/ha in crops in the presence of
sufficient organic waste. It is also a popular in sugarcane. Economics:
It has been found in tests that the production cost for 1 tonne of
vermicompost and 1,000 earthworms is around Rs 500 and 50,
respectively. About 3 tonne vermicompost can be harvested in 10 beds. |
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Killing
pests sans chemicals In the conventional high-input agriculture, the use of
pesticides reduces the population of bio-friends drastically, which
disturbs the foodchain and ultimately natural pest management. To
revive this natural balance, it is necessary to stop the use of
synthetic pesticides and create a conducive environment for
bio-friends. This can be done by creating an unfavourable environment
for pests and increasing the population of natural enemies of pests.
We can also use extracts of plants that obstruct the life support
system of the pest. The pest population that remains after cultural
practices can be further reduced by both, natural enemies—which can
be called bio-friends— and plant extracts — or
bio-agents. Conservation of natural enemies of pests is an important
element in pest management, for many insect parasites are more
susceptible to insecticides than the pests they attack. Bio-friends,
the natural enemies of insect pests, are abundant in nature. Viruses
such as nuclear polyhedrosis viruses (NPV) and granulosis viruses (GV),
bacteria like Bacillus thuringensis, fungi like Metarhizium,
Beauveria and Verticillium and protozoa like Schizogregarine
cause diseases in insects and destroy them. Similarly, general
insect parasitoids (parasites thriving on insects) are also known in
nature. Trichogramma is an egg parasitiod of several pests,
particularly of sugarcane internode borer. Insect predators such as Chilocorus,
Pharoscymnus, Cryptolaemus, Scymnus and Menochilus
feed on mealy bugs, coccids, scales, and mites on citrus,
grapevine and guava. Certain birds like owl can eat up to 1600 rats
a year and mammals like bat eat several nocturnal pests. The
efficacy of such bio-friends can be increased by the following
practices: Bird perches: Suitable nesting boxes can be kept
for predatory birds and wasps (Polistes sp.) and burlap traps
are placed around citrus trees for attracting Coccinellid predatory
insects that eat mealy bug. Food and shelter: Flowering plants
can be planted on the bundhs to provide supplementary food to
predators like Chrysopids, Coccinellids, predatory
mites, Syrphid flies and parasitoids. Control of ants: Ants
interfere with the activities of predators and parasitoids. Control
and physical exclusion of ants by putting a band of some botanical
barrier around the trunk in citrus orchards increases the efficiency
of Coccinellid predators and several parasitoids. Cultural
practices: Avoid burning trash in sugarcane fields. This would
protect the parasitoid Tetrastichus pyrillae of sugarcane
pyrilla. Strip cutting in alfalfa helps in shifting the predators of
pests to a nearby cotton crop. Regular removal of fallen apples and
their destruction reduces the overall population of codling moth. The
egg parasitoids released in such orchards are much more
effective. There are a number of examples wherein cultural lowering
of pest population gives opportunity for the natural enemies to be
more effective. If the water spouts in citrus are removed, the
population of leaf-miner, scale-insects, citrus psylla and mealy bug
is reduced. Trap crops: This is a strategy by which biological
control could be made more effective and economic. The target pest is
attracted to the border rows of a trap crop that is more preferred
than the main crop. The pest on the trap crop is more economically
tackled through biological control in a restricted area. Planting of
castor around tobacco nurseries and marigold around the main crop for
attracting Spodoptera and Helicoverpa (Heliothis),
respectively, and releasing egg parasitoids or spraying nuclear
polyhedrosis virus could give effective suppression. Conditions
for efficacy: The time and period of release should be suitable
for the natural enemy. It should synchronise with a suitable stage of
the pest. The release of Trichogrammatid egg parastoid would be
more effective if the release is based on information collected
through pheromone traps. Using a suitable strain (through artificial
selection) adopted to a particular crop ecosystem and pest management
practice increases the success of biological control. The searching
efficacy of parasitoids is increased by applying certain chemicals
called pheromones, which are originally isolated from their host
species (e.g., Trichogrammatid egg parasitoids). Phago-stimulants
are applied to the plants to encourage the ingestion of leaves sprayed
with microbial agents. For discouraging the activity of
hyperparasites, parasitoids should be released at a time when the
activity of hyperparasitoids is the least. The Indian government has
banned the export of frogs, because 90 per cent of the food of frogs
is agricultural pests. It has been estimated that catching frogs for
export led to the survival of 200,000 tonnes of pests, thereby
requiring farmers to spend more on pest control. It is good to use
locally made bio-friends and bio-agents as they have a short active
life. Also, transportation over distances decreases their
effectiveness. Producing bio-friends: Production of bio-agents
and bio-friends does not need very sophisticated technology. For
example, after crushing neem seed, put the material overnight in water
and the next day filter it through cloth, dilute with water to the
recommended level and spray immediately on the crop. This on-site
preparation is cheaper and more effective than the formulations
available in the market. Similarly, bio-friends like Trichoderma,
Trichogramma, NPV, etc., are very easy to multiply on farms. |
