FIELD OF INVENTION
The present invention relates to harvesting of crop waste/ crop straw, more
particularly, it relates to harvesting of left-over crop straw in the field after
harvesting by conventional methods using combine harvester, reapers or strippers.
BACKGROUND OF THE INVENTION
India is one of the countries whose economy is significantly dependant on
agriculture productivity. Cultivation of many crops, be it rabi or kharif, produce
straw as one of the bi-product post harvesting. Straw makes up more than half of
the yield of crops such as rice, wheat, barley, rye, oats, etc. This straw has many of
its benefits, like it can be fed as diet to cattle or horses; can be used for basketry
and other craft work; can be used as biofuel as substitute to coal; and can be used
as construction material. Though many farmers across the country do not realize
these advantages and take it as a left over waste of cultivated crops having no use.
Treating it as waste and open burning of straw is a common practice, not only in
India, but in most of the countries. Disposal off or burning of straw in open
environment has its own disadvantages. Openly disposing or burning off the straw
bale adversely affects the environment, for example it degrades the soil quality,
decreases its nutritional value, affects soil microbial structure and minimizes soil
water content. The smoke released from burning of the bale mixes with the air,
causing pollution and affecting public health.
Apart from other seasonal crop varieties, India produces 98 million tons of rice
paddy with roughly 130 million tons of straw. Of this, about half is used as animal
fodder. The rest is mostly burned in the fields, though a small amount is also
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consumed by brick kilns and paper and packaging industry. Despite such huge
amounts of straw generation, farmers in the country are yet to realize the potential
of this agro-waste in terms of manure and as a profitable raw material for various
industries.
The practice of burning the straw has a substantial negative effect on the
environment. More than 90% of the 17 Mt of rice stubble in Punjab are burnt each
year, resulting in thick smoke blanketing the region, since the burn-off occurs over
a short period (Singh et al. 2008, p. 3). The air pollution caused by this burn-off
has serious adverse health effects on humans and animals; it has been blamed for
causing road accidents and the closing of airports due to poor visibility (Singh et
al. 2008, p. 14). Furthermore, the burning results in the loss of nutrients and
organic matter from the soil.
Burning causes almost complete nitrogen (N) loss, phosphorus (P) losses of about
25 percent, potassium (K) losses of 20 percent, and sulfur (S) losses of 5 to 60
percent. The amount of nutrients lost depends on the method used to burn the
straw. In areas where harvesting has been mechanized (e.g., Thailand, China, and
northern India), all the straw remains in the field and is rapidly burned in situ;
therefore, losses of S, P, and K are small. In Indonesia and the Philippines, straw is
heaped into piles at threshing sites and burned after harvest. The ash is usually not
spread on the Better Crops, and this results in large losses of minerals…K, Si,
calcium (Ca), magnesium (Mg)…leached from the ash piles, although nutrients
contained in the relatively long stubble (30 to 40 cm) remain in the field.
Moreover, such a practice results in a significant transfer of nutrients from the
periphery of the field to the center, or even from surrounding fields to the center
field where, after threshing, the residues are burned. Over time, this practice
results in the accumulation of nutrients (K, Si, Ca, Mg) in some parts of the field
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and nutrient depletion in other parts. Burning causes atmospheric pollution and
results in nutrient loss, but it is a cost-effective method of straw disposal and also
helps reduce pest and disease populations that may occur due to re-infection from
inoculum in the straw biomass.
Open field burning of harvested residues has become a controversial source of
visible pollution across the country. Because of the high visibility and potential
hazard of the smoke, many residents and public officials are demanding severe
curtailment of burning. These producers contend that other waste disposal
methods are expensive, unreliable during wet weather, and too demanding of labor
and equipment during the busy harvest season. Both local and state policymakers
are being pressured to find an efficient and equitable solution to the problem.
The practice of burning causes serious problems for people and livestock in the
region. Burning this bi-product reduces visibility and increases harmful fine
particulate matter in the atmosphere. Regional studies have shown that there are
increased road accidents and traffic delays because of the poor visibility, and that
airports and roads have needed to be closed. There have been studies which have
even shown increased numbers of people attending hospital with respiratory
problems during the burn-off period.
Plumes of smoke arising from the fields are a common sight in Punjab during rice
harvesting season. In the months of October-November it almost asphyxiates
anyone who ventures out of house, be it a village or city.
Straw that is burned in the fields emits trace gases like carbon dioxide, methane,
carbon monoxide, nitrogen oxide, sulphur oxide and large amount of particulate
matters, which adversely affect human health as well as the environment. Last
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year, the magnitude of stubble burning was so high that it received international
attention. The National Aeronautics and Space Administration (NASA) released a
satellite image showing large number of fires across millions of hectares of
agriculture fields in Punjab.
Every year about 12 million tons of rice straw is burned in Punjab alone.
According to various studies, this leads to nutrient loss from the soil which is
equivalent to US $18 million worth of urea.
With several applications, increasing demand and competitive prices, it seems
farmers have no dearth of options for managing the agro-waste in a profitable way.
However, convincing them about economic viability of the options could be a
challenge.
It has been argued that farmers will give up the practice of burning agricultural
straw only if the cutting of left straw is cheaper and they receive a lucrative
incentive for the chaffed straw.
To address the above problems, the present invention aims at designing and
developing an innovative straw harvester which is not only able to harvest the left
over straw to its full but also has the capability to produce chaff from such
harvested straw.
OBJECTS OF THE INVENTION:
The object of the present invention is to develop an innovative straw harvester
capable of harvesting left-over straw completely from the crop field.
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Yet another object of the invention is to provide a system in the harvester to
produce chaff from the harvested straw.
In another preferred embodiment, the harvester system further comprises a
collecting means to collect the chaff from the straw.
SUMMARY OF INVENTION
According to an aspect of the invention, there is provided a straw harvester which
is capable to harvest the straw. The straw harvester includes a cutter reel at front
end of the straw harvester. The cutter reel is configured to cut straw of left over
crops from ground. This cut straw is then placed on a feeding conveyor using an
auger. The straw harvester, further contains a chaff-cutter configured at the end of
the straw harvester. The feeding conveyor feeds the cut straw to the chaff-cutter
that performs its chaffing.
According to another aspect of the invention, there is provided a method of straw
harvesting. The method includes cutting straw that is left over from crops, from
ground using a cutter reel. The cut straw is then collected using an auger and
placed on a conveyor. The cut straw is then conveyed to a chaff-cutter to perform
chaffing on the cut straw.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
The invention will now be described in more detail with reference to the
accompanying drawings, in which
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Figure 1 shows perspective view of straw harvester according to an embodiment
of the invention.
Figure 2 shows a flow chart depicting a method according to an embodiment of
the invention.
DETAILED DESCRIPTION OF THE INVENTION:
In describing the embodiments of the invention, specific terminology is resorted
for the sake of clarity. However, it is not intended that the invention be limited to
the specific terms so selected and it is to be understood that each specific term
includes all technical equivalents that operate in a similar manner to accomplish
a similar purpose.
Illustrative embodiments of the invention now will be described more fully
hereinafter with reference to the accompanying drawings, in which some, but not
all embodiments of the invention are shown. Indeed, the invention may be
embodied in many different forms and should not be construed as limited to the
embodiments set forth herein; rather, these embodiments are provided so that
this disclosure will satisfy applicable legal requirements.
The present invention provides a straw harvester as shown in the accompanied
figures. The harvester consists of the cutting mechanism, the feeding mechanism
and the chaff making means.
Referring to FIG. 1 that discloses a perspective view of a straw harvester 100
according to an embodiment of the invention. The straw harvester 100 includes a
cutter reel 102. Cutter reel 102 is configured to pull in straw remaining after crops
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are cut and cut the straw from as near the ground as possible. There may be
various configurations of cutter reel 102 available for such functioning. There may
be multiple blades provided on the cutter reel in order to efficiently cut the straw
from the ground. The cutter reel 102 rotates on its axis, rotation being powered by
a motor through an axle or conveyor means (not shown in FIG., such rotation
causes pulling of the straw inwards and hence provides more efficiency in cutting
of the straw. The cutter reel 102 is provided at front end of the straw harvester
100. It is kept in place by using a support frame 116. Support frame 116 also
provides rigid support to all other components of straw harvester 100 as well. The
cutting reel 102 is followed by an auger 104. The auger 104 moves the cut straw
by the cutting reel 102 and feeds it to a feeding conveyor 106. The auger 104, uses
a rotating helical screw mechanism to move the cut straw. The auger 104 may be
placed horizontally or at an inclination in order to increase its efficiency. The
rotation of auger 104 may be caused with the help of a motor (not shown in FIG).
The rotation of the auger 104 can be varied in order to achieve variable transfer
rate of the cut straw. The feeding conveyor 106, includes multiple spike like
projections 108 that helps to catch the cut straw from the auger 104 and move it
forward. This cut straw moves through this feeding conveyor 106 and gets fed to a
chaff-cutter 110. The chaff-cutter 110 is provided at the rear end of the straw
harvester 100. Chaff-cutter 110 includes multiple blades 112a, 112b that help in
chaffing the cut straw fed into the chaff-cutter 110. This way the cut straw is
efficiently cut rather than getting wasted.
Still referring to FIG. 1, there might be placed a storage bin (not shown in FIG.)
that might be placed after the chaff-cutter 110 in order to collect the chaff of the
straw. However, this storage bin may also be replaced by a simple spreader, also
not shown in FIG. This spreader is configured to spread the chaffed straw on to the
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ground where it can be mulched with the soil in order to function as compost for
the ground and increase productivity from the ground.
Now referring to FIG. 2 of that illustrates a flow chart depicting a method 200 for
straw harvesting. The method 200 initiates from step 202, wherein straw left over
after cutting crops is cut using a cutter reel that is placed in frontend of a straw
harvester. The cutter reel contains multiple blades that are fixed on to the cutter
reel. The cutter reel rotates on its axis and pulls the straw inwards and the blades
cut the straw. This straw is cut as close to the ground as possible. Further, at step
204, the cut straw is collected by using an auger. Also, the auger helps in feeding
the collected straw at previous step to a conveyor belt at step 206. The conveyor
belt is motor powered (not shown in FIG.) and is rotated using two rollers
powered by the motor. The conveyor belt further contains spiked projections on its
surface in order to efficiently collect the cut straw. A preferred movement of the
conveyor belt is towards the auger. The conveyor belt collects the cut straw and
feeds it to a moving collector (not shown in FIG.) at step 208. The moving
collector has collection fins that move the cut straw towards a chaff-cutter. The
chaff-cutter is in a rotating mode, powered by a motor, and chaffs the fed in cut
straw with the help of multiple blades that are placed on the rotating chaff-cutter.
The rotation of the chaff-cutter can be varied according to the feeding speed of the
cut straw. The chaffed straw may be, at step 210, then collected using a storage bin
at rear of the straw harvester or spread on to the ground utilizing a spreader. This
spread chaff helps in creating compost and enriches the ground for better
cultivation as well.
Various modifications to these embodiments are apparent to those skilled in the art
from the description and drawings herein. The principles associated with the
various embodiment defined herein may be applied to other embodiments.
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Since other modifications and changes varied to fit particular operating
requirements and environments are apparent to those skilled in the art, the
invention is not to be considered limited to the example chosen for purposes of
disclosure, and covers all changes and modifications which do not constitute
departure from the true spirit and scope of this invention.
This written description uses examples to disclose the invention, including the best
mode, and also to enable any person skilled in the art to practice the invention,
including making and using any devices or systems and performing any
incorporated methods. The patentable scope of the invention is defined in the
claims, and may include other examples that occur to those skilled in the art. Such
other examples are intended to be within the scope of the claims if they have
structural elements that do not differ from the literal language of the claims, or if
they include equivalent structural elements with insubstantial differences from the
literal languages of the claims.

I Claim:
1. A straw harvester comprising:
a cutter reel configured to cut straw from ground;
a feeding conveyor configured to feed the cut straw with help of an auger
for chaffing; and
a chaff-cutter, wherein the chaff-cutter is placed at rear end of the straw
harvester, and configured to perform chaffing of the cut straw to form
chaffed straw; and
2. The straw harvester of claim 1, further includes a storage bin to store the
chaffed straw.
3. The straw harvester of claim 1, further includes a chaffed straw spreader to
spread the chaffed straw on the ground.
4. The straw harvester of claim 1, wherein the feeding conveyor runs is motor
powered.
5. The straw harvester of claim 4, wherein the motor is powered using a
battery.
6. The straw harvester of claim 5, wherein the battery is a solar battery.
7. A straw harvesting method comprising;
cutting straw from ground;
collecting the cut straw using an auger;
feeding the cut straw to a conveyor;
transporting the cut straw, by the conveyor, to a chaff-cutter; and
chaffing the cut straw, by the chaff-cutter.
8. The method of claim 8, wherein the conveyor is motor powered.
9. The method of claim 8, wherein the method further includes storing the
chaffed cut straw.