Ergonomic design, development and performance evaluation of a multipurpose agricultural hand tool carrier
Loading...
Date
2006
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CCSHAU
Abstract
In India, inspite of rapid progress in farm mechanization in small and
marginal land holding categories certain operations like sowing, transplanting, hoeing
and weeding are mainly performed with traditional hand tools and equipments. In the
present day situation, the application of ergonomic principles are relevant for
providing proper design of hand tool and farm equipment which can increase output,
reduce drudgery and increased compatibility.
Therefore, for farmers of small and marginal land holdings categories a
multipurpose hand tool carrier along with attachments (seed-cum-fertilizer drill, cycle
wheel hand hoe and rolling-type crust breaker) were ergonomically designed developed
and tested for performing various operations such as sowing, crust breaking, hoeing
and weeding by manual labour.
Seed metering roller is the most vital component for the seed-cum-fertilizer
attachment that should meter the required quantity of seed accurately and uniform
with minimum seed damage. Triangular cells type rollers were used for metering seed
and fertilizer in seed fertilizer drill. The lab and field performance evaluation of
manually operated seed-cum-fertilizer drill attachment in term of quantity of seed
metered at different seed depths in box (full, 3/4th, 1/2nd, and 1/4th positions), seed
distribution pattern, placement of seed and fertilizer, draft requirement, field
capacities, and cost of operation was carried out in wheat, gram and bajra crops.
There was no effect seed-metering roller on seed damage, because higher seed
germination percentage i.e 88.66%, 86.0% and 87.33% recorded in wheat, bajra and
green gram crops, respectively. The draft of the seed-cum-fertilizer drill was well with
in the reach of an average operator. Average draft requirement of the machine were 12
kgf, 11.83 kgf and 11.67 kgf at sowing depths of 5.63, 5.33 and 5.00 cms in wheat, XXXVIIbajra
and green gram crops, respectively. But in gram crop it was 14.90 kgf, which is
on the higher side, because of increased sowing depth (8.67 cm). Therefore while
sowing the gram crop two persons may be used to operate the machine.
The performance of improved cycle wheel hand hoe indicates that average
weed intensity (No. of weeds/m2) after weeding operation by this attachment recorded
were 22, 11, 19 weeds/m2 respectively. As compared to this 27, 13 and 22 weeds/m2
were recorded after the use of iron wheel hand hoe. The average weeding efficiencies of
improved cycle wheel hand hoe in wheat, gram and pea crops recorded were 86.85,
92.34, and 88.55%, respectively and with iron wheel hand hoe these values were
83.94, 91.31, 86.84%, respectively. The weeding performance of the cycle wheel hand
hoe in all crops was better than the iron wheel hand hoe.
There was significant improvement in the seed germination of bajra, green
gram and cotton crop with the use of crust breaker. The seed germination ranged
between 20 plants/m2 to 24 plants/m2 in bajra crop, 16 plant/m2 to 20 plant/m2 in
green gram crop and 7 plants/m2 to 12 plants/m2 in cotton crop in crust formed
conditions while after the use of crust breaker the seed germination recorded were 51
plants/m2 to 57 plant/m2, in bajra crop, 57 plant/m2 to 67 plant/m2 in green gram
crop and 43 plants/m2 to 51 plants/m2 in cotton crop seven days after breaking of
the crust. This means, the plant population of bajra, green gram and cotton crops
increased by more than two times that of observed under crusted conditions.
Ergonomic performance evaluation of multipurpose tool carrier with
attachments (seed-cum-fertilizer drill, cycle wheat hand hoe and crust breaker) was
also carried out in different crops.
There was significant effect on physiological parameter of the operator at
different time durations of use of manually operated seed-cum-fertilizer drill in all the
crops.
The average energy consumed in operation of the seed-cum-fertilizer drill was
much lower and well with in the reach of an average operator. The energy consumed
after 30 min of its use by the operator were 6.12, 6.44, 6.76 and 6.59 kJ/min. Thus,
the machine resulted in less fatigue to the operator because of ergonomic design
(lightweight, less draft and appropriate handle height) in sowing wheat, green gram
and bajra crops.
Similarly, lesser power/energy was required in the use of improved cycle wheel
hoe for hoeing and weeding operation in different crops. Only 5.01, 6.17 and 4.69
kJ/min power of operator was consumed in operation of improved wheel hand hoe in
above crops as compared to 5.70, 7.02 and 5.59 kJ/min after 30 min of use of iron
wheel hand hoe. Higher values of group force and less decrease in grip force (fatigue)
of both the hands of operator indicates that the use of improved cycle wheel hoe in all
the crops was less tiring to the operator.
The average systolic and diastolic blood pressures of the operator of
ergonomically designed crust breaker were lower than the existing crust breaker.
Lesser energy was required to operate the ergonomically designed crust breaker.
Moreover, decrease in grip force (fatigue) was much less in the improved machine.
After operation of existing crust- breaker the grip force of worker reduced by 17.88%
and 16.89 % in right and left hand, respectively in comparison to only 5.8% and
7.28%, respectively in improved crust breaker. Therefore, improved crust breaker was
ergonomically more efficient and less tiring to the operator.