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Conservation agriculture
April 26: Due to
increasing population and demand for food grains,
declining water resources, increasing cost of
inputs, machinery, energy, increasing
desertification and deteriorating soil and
environments , a new approach known as the
conservation agriculture is gaining ground in the
world.
 The green revolution model which requires high
inputs and expensive technology, could not lead to
the sustainable betterment of small and resource
poor farmers of the developing world. In other
words, it has failed to reduce poverty in the
third world and it also faces environment crisis
such as increased soil erosion, salinization,
pesticide pollution, desertification, loss of
bio-diversity and natural resource base.
However, the conservation agriculture seeks to
conserve, improve and make more efficient use of
natural resources through integrated management of
the available soil, water crop and other
biological resources in combination with selected
external inputs.
It represents a resource-saving and effective
agriculture which contributes to environmental
conservation and at the same time enhances
sustainable production. Its key features are:
No ploughing, disking or soil cultivation (i,e no
turning over of soil);it provides a method of soil
moisture conservation and saving irrigation; it
ensures that there is less run-off of valuable
water and more water infilteration compared to the
more traditional methods; it ensures crop and
cover crop residue stay on the surface crop
rotations and cover crops are used to maximize
biological control; no burning of crop residues;
permanent crop and weed residue mulch protects
soil erosion; it helps restore soil organic
matter; increases soil microbes that are useful in
the biological control of soil born pathogens; it
also increases yield because of timely planting,
effects on soil structure, water and biological
factors; decreases energy and labour costs for
farmers resulting in higher profits; it uses
specialized equipment; enables continuous
crop-land use.
These are just some of the key features of
conservation agriculture which may be used
according to the requirements of a site specific
and socio-economic conditions of farmers.
For instance, it was practised on 45 million
hectares in 1996-97 mostly in the USA, Canada,
Brazil, Argentina, Mexico, Paraguay, Australia,
etc, but now it has spread to over 72 million
hectares in 50 countries including China and those
in South East Asia.
Conservation agriculture is now applicable to all
crops, soil and environmental conditions and
encompasses a wide range of agro-ecological zones,
from north to south and lowland to hilly lands and
highlands; farm sizes and cropping systems from
subsistence, hand-hoe based small farms to large
broad acre fully mechanized farms in Australia and
USA and under both rain-fed and irrigated
conditions.
The FAO has also been promoting conservation
agriculture for over a decade, particularly in
Latin America. As conservation agriculture is
becoming a great success story for increasing food
security and reducing poverty in this continent,
the FAO has officially adopted this concept as one
of its major activities and as a result is
expanding this programme to Africa, Central and
South East Asia. Some of the conservation
agriculture also known as conservation tillage.
The conditions obtaining in Pakistan are discussed
as under:
SURFACE SEEDING:
It is the simplest system for wheat but can also
be used for other crops including rice. The seeds
are broadcast onto the saturated soil without any
tillage operation.
This is the only system for low lying poorly
drained heavy rice soils that don't allow timely
tillage operation for sowing wheat and thus remain
fallow in the winter season as in Nepal.
This practice cuts the cost of production by more
than a third and requires no implements. Due to
these advantages even the resource poor farmers
are now increasingly using it in Nepal and
Bangladesh.
This method has a good potential for small,
subsistent and below subsistent-level farmers.
However, sowing on the open soil surface makes it
possible for seed to be damaged/eaten by birds. To
protect the seed from bird damage it is essential
to prepare a thin layer of cowdung on seed surface
before seeding.
BED-PLANTING:
This system is used in many countries for wheat,
rice and other crops. Beds are formed every crop
season. The configuration is variable, but in
South Asian rice wheat areas, two beds are formed
to fit between the two tractor wheels.
Each bed is about 70cm wide and 1 to 3 rows are
planted on top of beds depending on the crop.
Similarly permanent bed systems are used for a
number of crops. This reduces the cost of bed
formation and is essentially zero or reduced
tillage on beds.
RICE PLANTING:
Rice is generally grown as a puddled and
transplanted crop to reduce water percolation
losses and weed infestation. Paucity of labour in
peak rice transplant season, increasing
transplanting and puddling costs and inadequate
population planted per unit area by the hired
labour has necessitated the need for alternate
methods for establishing rice crops direct seeding
of rice is one of the options, where rice seed can
be seeded directly into moist soil using drills or
else pre-soaked, pre-germinated seed is broadcast
into the puddled soils.
Direct seeded rice has the advantage of faster and
easier planting, less labour and drudgery and
earlier crop maturity by more than 10 days as
compared to transplanted rice. Again, Chinese have
developed a parachute rice planting technology in
which seedlings are raised in plastic bubble
sheets and then blown high in the air to make them
land upright in the puddle fields.
This method saves labour and is quick and cost
effective. Some other methods like dry seeding of
rice as in other crops, bed-planting of rice by
transplanting or dry seeding on the top or sides
of the bed and seeding on moist soil like
zero-till wheat, are also used according to the
situation,
REDUCED TILLAGE:
Chinese made 12 horse-power two-wheel diesel
tractor that prepares the soil and plants in one
operation (reduced tillage). It allows timely
sowing of wheat after rice even in poorly drained
low-lying areas and still lowers the cost of
cultivation by one-third and increases yield by
one-fourth.
It can command 12 hectares of land and can be
locally repaired. This tractor is now being
increasingly used by farmers especially small
farmers in Nepal, Bangla Desh and Indo-Gangetic
Plains.
It has great potential of timely sowing of wheat
in the rice-wheat belt and thus increasing
production of wheat, The policy makers should
seriously consider to introduce this technology at
the earliest.
ZERO TILLAGE:
This technology consists of a Newland madezero-till
seed drill driven by a four wheel tractor but its
high cost was one of the limiting factor for its
use. However, due to the efforts of Directorate of
On Farm Water Management, Lahore, and Agricultural
Department, Ludhiana (India).
This drill was locally made at cheaper rates in
their respective countries. It places both seed
and fertilizer directly into the soil in standing
rice stubbles without prior tillage.
It saves cost of cultivation upto Rs2000 in
Pakistani Punjab and Rs3000 even after paying rent
of hired tractor in Haryana State of India. It
saved water up to 20 per cent, reduced cost of
diesel and increased yield per hectare by 15-20
per cent.
HAPPY SEEDER:
The burning of rice stubbles in several rice
growing areas of the world to aid in the seed bed
preparation for the subsequent crops causes two
major problems.
First it causes environmental pollution problem
affecting human health in the rice growing areas
and secondly it causes reduction in soil organic
matter due to burning of rice stubbles which is a
threat to long term soil health.
The happy seeder approach enables direct drilling
into heavy stubble and trash in wet or dry
conditions by simultaneously removing the
stubble/trash and direct drilling into bare soil.
It is able to sow a field immediately the
harvester has passed, thus providing an option for
timely sowing and using soil moisture before it
evaporates. It saves many passes with tillage
implements a common practice on the sub-continent,
even after burning of stubbles.
This technology reduces the risk of wind and water
erosion, improves soil organic matter content,
structure and infiltration, and reduces
evaporation from the soil surface thus potentially
improving water use efficiency.
PLASTIC COVERING:
In order to make full use of water in water
deficit hilly areas of northern China, its
agronomists have invented a plastic covering sheet
for conservation agriculture.
This technique significantly increased their water
use efficiency on their hilly lands where only one
crop a year could be taken, now two or three crops
are taken in a year.
The main points of this technique are, applying
fertilizer as basal, making raised bed and
covering plastic sheet on bed, planting wheat on
furrows in the fall; and planting summer crops
such as sweet potato, tobacco, peanuts or maize in
early summer of coming year.
HYDRO-TURBINE:
The Indus plain have several mighty rivers and
small perennial streams and drains that flow
throughout the year If flow energy of water in
these streams and rivulets is harnessed by using
the Chinese hydra-ramp turbines it may not only
produce five kw of hydra-power but lift water over
30 metre height on the side of a stream bank
having a cultivable area at 60-70 liters per
second.
Installation of such pumps on seasonal steams may
also help to lift and store water in the storage
ponds during monsoon season and use it as
supplemental irrigation to rain-fed crops during
post monsoon season to increase yields of rain-fed
crops. This technology is fast spreading in South
Asian countries including the Indo-Gangetic
plains.
These are just some of the conservation
agriculture technologies used worldwide and have
great potential to conserve our declining resource
base and increase production of food grains to
meet the increasing food requirements of our
burgeoning population The policy makers should
develop a comprehensive programme of developing
conservation agriculture in Pakistan with the
assistance of the FAO as it has already become its
part of development programmes.
The DAWN |
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Pakissan.com; Advisory Point
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