Sowing
Equipment
Sowing equipment
Seed drill
Broadcasting devices
Gorru
Tanu seed grill
Wide bed former
Seed cum fertilizer drill
Sowing Equipment
- Important factors that affect seed germination
and emergence include
- the viability of the seed (percentage germination
under laboratory conditions)
- soil temperature
- availability of soil moisture to the seeds
- soil aeration and' the resistance of the
soil to seedling emergence
- These are influenced by the soil type,
the physical condition of the soil, depth of sowing / planting,
the intimacy of contact between the seed and the soil, the degree
of compaction of the soil above the seeds and formation of surface
crust after sowing.
- Final field emergency stand is also influenced
by pre-emergence, physical losses by birds and the post emergence
losses due to diseases; insects and adverse environmental conditions.
- It should be apparent that sowing equipment
can not control all the factors involved in the emergence.
- Sowing is the art of placing the seed in
the properly prepared bed, at optimum depth, at uniform spacing
so that the recommended seed rate is maintained.
- Most of the crops under optimum irrigation
condition are sown on flat surfaces.
- Under too low or too high rainfall conditions,
the sowing is done in furrows or on ridges and the root crops
are generally sown on ridges.
- The different methods of sowing are (i)
Broad casting, ii) Dibbling, iii) Seed dropping behind the plough,
iv) Drilling, v) Hill dropping, vi) Check rowing and vii) Transplanting.
Broad casting
- is the scattering of the seeds on the field surface
after broadcasting, they are covered by manipulating the soil.
- In this case, the intercultural operations can
be carried out only with hand tools.
- Millets, upland paddy and other rain fed crops
are boradcasted.
- This is the method broadly adopted for nursery
raising in the low land rice cultivation.
Dibbling
- is the process of placing the seeds in holes
at definite depth made in seed bed and covering them.
- The and tool used is called dibbler which has
many conical projections made in a frame.
- This is adopted for small plots and is generally
used for vegetable crops.
Seed dropping
- behind the plough in the furrow made by the indigenous
plough is a common method used in most of the dry land areas.
- A man or woman following the plough drops the
seed by hand and the seed is covered when the next furrow is opened.
Drilling
- means dropping the seeds in the furrow through
send tubes. Metering of seed may either be done manually or mechanically.
- The accuracy of depth of placement, spacing and
amount of seed sown are much higher than the other methods.
- The rear covered is also more.
- The only disadvantage is that seeds may sometimes
get damaged and get clogged during operation Drilling can be done
either manually (behind the country plough) or by tractor drawn
seed drills.
Hill dropping
- In hill dropping the seeds are sown in lines
as in drilling and seed dropping in line is also controlled.
- Unlike drilling the seeds are dropped at a fixed
spacing and not in a continuous stream.
- In hill dropping, plant spacing in a row
is also maintained.
check rowing
- is the method in which the spacing between
the rows is the same as that between the plants.
- This makes it possible to do inter culture
in both directions.
Transplanting
- of seedlings is commonly done for paddy
vegetable crops and flower plants.
- Due to the better care given to the plants
in the nursery stage, transplanted seedlings given more yield.
- This is a labour intensive and time consuming
operation.
- Transplatner is the machine used for this
purpose.
Components and functions of seed drill
-
The functions
of a seed drill are
-
to carry
adequate quantum if seeds
-
to open
a furrow of uniform depth
-
to meter
the seeds
-
to cover
and deposit the seed in the furrow properly
-
to cover
the seeds and compact the soil around the seed.
-
In the
case of manually metered seed drills, a funnel is attached near
the handle and the seed is conveyed in seed tubes and dropped
below the shoe and then covered by the soil.
-
In case
of mechanically metered seed drills, the components are i) frame
ii) seed box iii) seed metering mechanism iv) furrow open v)
covering device and vi) transport wheels.
-
The frame
is usually made of angle iron with suitable braces and brackets
and should be strong enough to withstand all types of loads
in working condition.
-
The seed
box is made of M.S. or G.I. sheet with a cover and should be
of sufficient capacity.
-
A small
agitator may be provided to prevent clogging in it.
-
Seed metering
mechanism allows the flow of seed into the seed tube at predetermined
interval and normally draws power from the land wheel through
gears.
-
The furrow
opener opens a uniform depth of furrow in front of the seed
tube.
-
The covering
device moves behind the furrow opener and immediately collects
the soil and covers the seeds.
-
The transport
wheel helps in easy conveyance of the seed drill and the rotary
power is drawn to run the seed metering mechanism, through a
clutch arrangement.
Seed metering mechanisms
-
The fluted
feed roller has longitudinal grooves throughout its periphery,
which rotates with the axle over which it is mounted and throws
the grains out on the adjustable gate, from where it falls into
the grain tube.
-
The fluted
roller is mounted at the bottom and can be shifted sideways.
As the length of the roller exposed is more, the amount of seed
dropped increases. The feed rate can be controlled by positioning
the bottom plate.
Cup Feed Mechanism
-
In this
type, the seed box is of two sections, viz., seed storage box
end feed box.
In thefeed box, a disc with no. of cups fixed in the periphery
is fixed on a spindle, which receives power from the land wheel
through appropriate gears or chain drive.
-
The cups
may have two faces one with larger groove and the other with
smaller ones.
-
The seed
will be carried by the individual cups when spindle rotates
and dropped into the funnel of the seed tube by gravity.
-
The seed
rate is governed by the speed of rotation of the disc.
-
The mechanism
normal has arms with jaws, which will pick the large, size seeds
like potato or seedlings for transplanting (like paddy) and
place it in the seed bed.
-
The potato
planter has radially projecting arms fixed on the land wheel,
whereas in the transplanter the jaws are fixed on a horizontal
arm.
-
Some of the bullock drawn seed
drills has this mechanism.
-
The brush will receive power
from the land wheel and rotate at the bottom of the seed box.
-
The holes in the seed box bottom
will be opened and closed by the brush in the predetermined
pattern and allows the seed to pass through at regular intervals.
-
Furrow
opener is that part of the seed drill which opens a uniform
furrow to place the seed at appropriate depth.
-
The different
types of furrow openers are (a) shoe type, (b) hoe type, (c)
single disc type and (d) double disc type.
-
The shoe
type furrow opener, works better in the poorly prepared seed
bed.
-
They are
made of two curved runners with their cutting edges on the ground
and meeting at the share point.
-
The hoe
type of furrow opener, is having a single or double point shovel.
-
The seed
tube is fixed behind the shovel.
-
The disc
type is favoured where the seed bed consists considerable plant
residues.
-
The single
disc opener has a small disc, with little disc angle, which
shifts the soil to one side.
-
The seed
is dropped behind the disc.
-
In the
double disc type, the two discs are placed closer and opens
furrow, in which the seed is dropped in between the discs precisely.
-
This component
of the seed drill is attached at the rear side to close the
furrow after the placement of seed.
-
It may
be a lengthy plank, drag chain roller or press wheel or miniature
bund former.
-
This process
helps in driving the air present near the seed and allows required
moisture migration for germination of seed.
Transport wheel or land wheel
-
There will
be two wheels fixed one on either side of the main axle or one
each on two cut half axle.
-
The wheel
rim may be flat one or provided with lugs.
-
The wheel
may not have any rim and directly run on the sturdy spokes.
-
Any one
of these wheels or both may supply power to the seed metering
mechanism through a chain or gear drive.
-
Usually
a clutch will be provided to engage or disengage the power transmission
to seed metering device.
-
Broad casting technique
is adopted for the small grain crops.
-
A broad casting device
will have a hollow cylindrical seed box with no holes drilled
on its surface so that one seed can pass through at a time.
-
The cylinder will be fixed
on an axle with necessary covers and mounted on separate land
wheels.
-
The unit can be pulled
by a handle.
-
In operation the seed box
is filled with 80% of its total volume with the seeds and the
cylinder is rolling when it is pulled and seeds squeeze through
the holes freely and drop on the seedbed.
-
After completing the broadcasting,
the seedbed has to be given a light harrowing by means of a
blade harrow or plank, so that a thin layer of soil covers the
seed.
-
This is
animal drawn hand metered seed drill commonly used in Andhra
Pradesh and in northern districts of Tamil Nadu.
-
This normally
has a sturdy beam and handle made of karuvelam or babul wood.
-
Number
of tynes, usually 3 to 12 Nos, are fixed in the horizontal beam
to make furrows.
-
Bamboo
sticks are used as seed tubes.
-
The tubes
are pierced into the tynes.
-
The top
end is fixed below the seed bowl.
-
Usually
each seed bowl will have three to four seed tubes.
-
There are
two pole shafts attached to the beam.
-
The seed
drill is attached with the yoke and drawn.
-
The depth
of the furrow is controlled by the operator handling the implement.
-
The second
individual, usually woman labour, carries the seed and drops
it in the bowl uniformly so that the seeds are distributed evenly.
-
The rate
of sowing of the seeds depends on the efficiency of the individual
dropping the seeds in the bowl.
-
This seed
drill cannot be used for mixed cropping directly.
-
If desired,
two seed drills should be used simultaneously to sow the different
crops, or some of the seed tube can be blocked and the sowing
done by the third individual walking behind the seed drill.
Tanu seed drill
-
The unit consists of 7 sets of seed dropping
systems actuated by a common ground wheel.
-
It can be mounted over a tractor and used.
-
Two numbers of furrow forming channels
are fitted at both the edges of the body frame which form the
furrows.
-
The furrows serve as a water conserving
media for subsequent utilization of the rain water by the crop.
-
The rotors are edge-drop seed plates which
can be changed depending upon the seed type.
- Since individual seed hoppers are provided,
mixed cropping is also possible with this unit.
Seed cum fertilizer drill (Bullock
drawn)
-
The seed cum fertilizer
drill consists of two components for seed metering and fertilizer
metering systems.
-
The two systems have been
designed in such a way as to place the fertilizer in a continuous,
strip in the furrow at the bottom followed by seed placement
2.5 cm above the fertilizer line.
-
The furrow closers provided
at the rear gives the compaction for proper germination of seeds.
-
The implement saves nearly
Rs.68.75 per hectare when compared the conventional practice.
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