Performance Evaluation of a Modified Tractor Drawn Groundnut Digger/shaker for Agricultural Productivity Oyelade, O.A., Ademiluyi, Y.S., D. James and I.C. Ozumba National Centre for Agricultural Mechanization (NCAM), Ilorin

Abstract Field test was conducted to evaluate the performance of a NCAM modified tractor drawn groundnut digger/shaker. A 65 hp styer tractor was used for drawing this implement. The parameters evaluated were, soil moisture content, effective field capacity, theoretical field capacity, field efficiency, digging efficiency, percentages of damaged pods, exposed pods loss, unexposed pods loss, undug pods loss and total of pods loss. The experimental plots were laid side by side in a randomized complete block design (RCBD). Results of the main field test indicate that using the tractor drawn groundnut digger/shaker combination performed better than using the tractor drawn groundnut digger with highest average digging efficiency of 99.0% at a soil moisture content of 13.60% (db) with minimum percentage total of pod loss of 1.0%. While the tractor drawn groundnut digger recorded the highest average digging efficiency of 98.04% at a soil moisture content of 14.05% (db) with minimum percentage total of pod loss of 1.96%. Results obtained from this study also showed that digging efficiency and percentage of total pod loss are inversely related to one another signifying that at lower digging efficiency there would be high percentage of total pod loss and vice versa. Keywords: Evaluation, Tractor, Groundnut, Digger, Shaker, Performance 1.

Introduction

Nigeria has been one of the largest producers of groundnuts in the world. Even as far back as 1930 the total groundnut acreage was recorded as 421,052 hectares with a production of 316,684 tons. Nigeria has also been a leading exporter of the crop with generally 60% to 70% of production being exported (Kaul, 1978). Groundnut (Arachis hypogea) has several varieties namely: bunch or erect type, creeping type, Kano local, Kano 50 and castle cary. Its climatic requirement includes a temperature of 25 oC – 30 oC and a rainfall of 70 cm – 100 cm per annum. Its soil requirement for a better performance, groundnut needs to be planted on a coarsetextured sandy-loam soil, highly acidic to neutral/PH range of 5 - 7 and rich in calcium and phosphorous. These are essential for pod formation (Ogieva, 1998). Groundnut is propagated by seed. It is planted around March – April in the South and around late May – July in the North. Its land preparation comprises of clearing of bush, stumping, ploughing, harrowing and seed bed preparation and/or ridging. It can be a sole crop or intercropped. The plant depth is about 4 cm. The plant spacing is 40 cm – 60 cm x 20 cm. A times 15 cm between seeds and 40 cm or 60 cm between rows depending on the variety. It is planted by dropping 1 – 2 seeds per hole. It needs like 40 kg – 90 kg of the crop to be used for planting a whole hectare of land. The land needs to be weeded regularly using a hoe. Harvesting is done when the lower leaves 187

turn yellow and drop. This is when it is 4 – 5 months or 120 – 150 days after planting depending on the variety. It could be stored in either ways; stored in a clean rhombus or silos, unshelled pods are stored in sacks, shelled nuts are stored in bags and shelled nuts needs to be treated with insecticides before storage (Ogieva, 1998). Groundnut production, like most other crops is governed by the availability and interaction of many inputs like seeds, fertilizers, insecticides etc. Use of machines is one of the inputs which, apart from giving relief from drudgery, influences the efficacy of other inputs either directly or indirectly. Timely and correct placement of seeds, optimal harvesting procedures and timing, adequate shelling and related items are examples where machines could influence the production efficiency. Cost of production would also be influenced by the degree of usage of machines (Kaul, 1978). Groundnut harvesting operation usually consists of a series of operations comprising digging, lifting, windrowing, stocking and threshing. Among the field operations concerned with groundnut cultivations, harvesting is the most labourious and costly endeavour. The action method of harvest employed depends upon the type of groundnut grown. Harvesting may sometimes become a problem especially when the crop has passed the stage of full maturity and the soil has hardened. In this case, it is customary to lift the plants by loosening the soil either by working with a hand hoe, a plough or a blade harrows along the plant rows. If after lifting the crop manually it is observed that a good percentage of the pods have been left in the soil, the same implement may be used to pick the left over pods. In the case of the spreading type, the process of up-rooting the crop from the soil is a rather difficult operation as pod formation takes place all along the creeping branches of the plant. The pegs are comparatively thinner and more delicate. As compared to manual up rooting, the performance of the bullock-drawn digger is satisfactory and economical. The digger lifts groundnut plants from a depth of 10 cm to 12 cm several models are available in the market either by the animal draught or by the power tiller drive (3 to 6 hp). The capacity of various diggers ranges from 1.2 ha/hr (animal drawn) to 1.5 ha/hr (power tiller). The bullock-drawn groundnut digger can harvest groundnut crops over an area of 0.75 hectares in 8 hours. The maximum tractive power possible for short periods only is taken as 10 times the optimal level for reaching a near collapsing stage to about 3 times the optimal level for overcoming the inertia. Such reserve capabilities are a positive edge over similar powered mechanical engines or electric motors. Obviously increased in power demand will necessitate a reduction in work speed and/or reduction in work hours or both. It is estimated that a 10% increase in tractive power, and a 15% rise in speed would necessitate a 25% decrease in daily working time (Kaul, 1989). The major reasons for the demand for groundnut machinery are to reduce drudgery, to reduce timeliness, and to increase productivity and income. The most desirable machines indicated by farmers are stripper, digger, and planter for irrigated area; planter, stripper, and weeder for rainfed area; and stripper, weeder, and seed shelter for area using residual soil moisture (Chinsuwan et al., 1991). The traditional method of harvesting groundnut by digging the ridge through the aid of small hoes is labour intensive. This process is carried out at a soil moisture content of 12 % to 15 % (Kaul, 1978). In order to alleviate the drudgery involved in groundnut harvesting and as well looking at the previous work carried out in this area 188

of study in the country, the evaluation of NCAM modify groundnut digger/shaker is pertinent. Therefore, this paper presents the performance evaluation of a NCAM modified tractor drawn groundnut digger/shaker. 2.

Materials and Methods

The study was carried out at the National Centre for Agricultural Mechanization (NCAM), Ilorin. This fieldwork was carried out in November 2003 on the large cultivation plots of the experimental farm which offered the tractor drawn groundnut digger/shaker an exposure to wide range of soil condition for farming situations in the locality. The groundnut crop used for the study was planted on the 15th of July, 2003. A65 hp styer tractor was used for drawing the groundnut digger/shaker implement. A total area of 0.80 hectares of sandy loam soil was used for the main study. The field was divided into three different experimental plots with each plot having a dimension of 25 m by 100 m. Each of these plots was further sub-divided into two plots to allow for different operation of tractor drawn groundnut digger and digger/shaker combination. Trials were carried out on each of the plots at three days interval. This was done to assess the performance of the machine at various soil moisture contents. The remaining 5 m x 100 m left out of the field was sub-divided into two parts, which served as a demarcation between the shared plots. The soil moisture content was determined using the oven dried method. The speed of operation for the tractor was determined by taken the average time it took the tractor to cover the longest distance. The time factors (such as actual time, obstruction time and turning time) which were used for determining the total time for completing each tillage operation was measured with a stop watch. A 1m2 steel bar was used as marked area for taking samples of harvested groundnut plant, unharvested groundnut plant, damaged groundnut pods, exposed groundnut pods, detached groundnut pods lying exposed, detached groundnut pods inside the soil that fell within the 1m2 marked area on each selected pot. The samples from these selected pots were used to access the performance of the tractor drawn groundnut digger and digger/shaker combination. 2.1

Modifications made on NCAM developed groundnut digger/shaker

The modifications made on the NCAM developed groundnut digger/shaker include the following:

2.2

i)

correcting the angles of the three frames holding the picking spikes to 120 o to each other; and

ii)

providing locking devices at both ends to prevent the beam from removing when the shaker is in operation. Working principle of the modified NCAM groundnut digger/shaker

The digger consists of a single-place blade mounted on a frame with the help of two shanks/standards (Fig. 1). The shaker consists of two wheels supported by a main frame which has finger-like handles placed at distances equivalent to the planting intervals (Fig. 2). The cutting edge of the blade is adjusted to operate at a depth slightly below the pod zones. As the tractor moves forward, the blades cut the roots of the groundnut vines and loosen the soil. The shaker is then employed to pull out the vines from the loosened ground and shake off the soil adhered to the roots and 189

pods (Fig. 3). The plant can be left exposed on the ridges for 3 - 4 days for sun drying before collection for stripping and threshing. 2.3

Test parameters

Five samples were taken from each of the sub-plot, where parameters such as percentage exposed, buried, damaged, etc., were used for the computation of the machine losses and digging efficiency. This was done in accordance with the Indian Standards Test Codes for groundnut harvester, Animal drawn (IS: 11235 – 1985). The following formula was used in the computations: i)

A B C

ii) % of damaged pods =

(1)

C A

iii) % of exposed pods loss =

x

100

G x A

iv) % of unexposed pods loss =

H A

(2)

100 x

100

K x 100 A

v) % of undug pods loss =

(3) (4) (5)

where, A = total quantity of pods collected from the plant in the sampled area. B = quantity of clean pods collected from the plant dug in the sampled area, exposed pods lying on the surface and the buried pods. C = quantity of damaged pods collected from the plants in the sampled area. G = quantity of detached pods lying exposed on the surface. H = quantity of detached pods remained inside the soil in the sampled area. K= quantity of pods remaining undetached from the undug plants in the sampled area. vi) Digging efficiency =

100 total % of podloss

(6)

where, total % of pods loss = % of exposed pods loss + % of unexposed pods loss + % of undug pods loss vii)

Field efficiency =

Effective field capacity x 100 (7) Theoretical field capacity

where, theoretical field capacity is the rate of field coverage that would be obtained if the digger was operating continuously without interruption e.g. unclogging the blade, and turning time; effective field capacity is the actual average rate of coverage, which includes the lost time in turning at row end, adjustment-making, etc. 190

3.

Results and Discussion

Results of the harvesting operation carried out on the groundnut crop at 113 days after planting, 116 days after planting and 119 days after planting using the tractor drawn groundnut digger and digger/shaker trials at different soil moisture content conditions are presented in Tables 1 and 2, respectively. It can be deduced from Tables 1 and 2, that the soil moisture content generally fell within the specified range. As a result of this, it was discovered that as the soil gets wet the implement finds it easier to penetrate into the soil thereby resulting to a very high digging efficiency of the implement during operation. The weeds which interfered during the evaluation exercise of November, 2002 on the same implement were totally eliminated by weeding the plot towards the harvesting period of the crop. From Table 1, it can be deduced that the highest average digging efficiency recorded for the tractor drawn groundnut digger was 98.04% at soil moisture content of 14.05% (db) while the lowest average digging efficiency of 95.51% recorded for the tractor drawn groundnut digger occurred at a soil moisture content of 13.06% (db). This increase in digging efficiency was mainly due to the presence of water in the soil which aided the deep penetration of the digger into the soil. This implies that the soil moisture content has direct influence on the digging efficiency of the machine. The highest average effective field capacity and field efficiency obtained using tractor drawn groundnut digger was 1.07 ha/hr and 77.16%, respectively, both occurred at a soil moisture content of 13.06% (db). From Table 2, the highest average digging efficiency recorded for tractor drawn groundnut digger/shaker combination was 99.0% at soil moisture content of 13.06% (db) while the lowest average digging efficiency of 94.69% recorded for the tractor drawn groundnut digger/shaker combination occurred at a soil moisture content of 8.67% (db). The highest average effective field capacity obtained using the tractor drawn groundnut digger/shaker combination was 0.75 ha/hr occurred at a soil moisture content of 14.05% (db). The highest average field efficiency of 76.28% recorded for tractor drawn groundnut digger/shaker combination occurred at a soil moisture content of 13.06% (db). The low values obtained for both average effective field capacity and field efficiency of the tractor drawn digger/shaker combination (0.75 ha/hr and 76.28%) when compared to the high values obtained for the tractor drawn groundnut digger (1.07 ha/hr and 77.16%) was as a result of time spent for crop recovery. 4.

Conclusion

The results obtained from the evaluation of the implements led to the following conclusions: Soil moisture content ranging between 8% to 15% was found suitable for the harvesting operation of a matured groundnut farm. the study also reconfirmed that digging efficiency and total percentage of pod loss are inversely related to one another signifying that at lower digging efficiency there would be higher percentage of total pod loss and vice versa.

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References Chinsuwan, W., Wongpichet, S., Sudajan, S., Chakkapak, C., Krishsanaserani, S., Mongkolthanatas, J., and Thongsawatwong, P. 1998. Final Report Groundnut Mechanization Project: A Report Submitted to the International Development Research Centre (IDRC, Canada). IDRC File No. 3-P-87-0041. Kaul, R. N. 1978. An Overview of the Mechanization Position Groundnut Production in Nigeria: In Proceedings of the National Seminar on Groundnut Production. Pg. 50 – 58. Kaul, R. N. 1989. Animal Powered Equipment:: Some Factors Affecting Their Design; In Draught Animal Power Research and Development in Nigeria. Proceedings of the First National Workshop held at the National Animal Production Research Institute, Ahmadu Bello University, Shika, Zaria, Nigeria. Ogieva, E. 1998. Comprehensive Agricultural Science for Senior Secondary Schools, Pg. 172 – 173.

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Table 1. Efficiency of the implement (Digger) DAP Average Average Average Average Average Average Average Average Average Average moisture % of % of % of % of % of total % digging field theoretical content exposed unexposed undug total damaged of pod efficiency efficiency field (%) pod loss pod loss pod loss loss pod loss capacity (%) (%) (%) (%) (%) (%) (%) (%) (ha/hr) 113 13.06 0.77 3.72 Nil 4.49 Nil 4.49 95.51 77.16 1.3882 116 14.05 0.33 1.63 Nil 1.96 Nil 1.96 98.04 69.47 1.1685 119 8.67 2.58 0.17 Nil 2.75 Nil 2.75 97.25 66.07 0.9380 Table 2. Efficiency of the implement (Digger/Shaker combination) DAP Average Average Average Average Average Average Average Average Average Average moisture % of % of % of % of % of total % digging field theoretical content exposed unexposed undug total damaged of pod efficiency efficiency field (%) pod loss pod loss pod loss loss pod loss capacity (%) (%) (%) (%) (%) (%) (%) (%) (ha/hr) 113 13.06 0.65 0.35 Nil 1.00 Nil 1.00 99.0 76.28 0.9109 116 14.05 0.02 Nil Nil 1.02 Nil 1.02 98.98 68.70 1.0982 119 8.67 1.32 3.99 Nil 5.31 Nil 5.31 94.69 64.49 1.0192 DAP = Days After Planting

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Average effective field capacity (ha/hr) 1.0711 0.8118 0.6197

Average effective field capacity (ha/hr) 0.6948 0.7545 0.6573

Fig. 1: Pictorial view of the groundnut digger

Fig. 2: Pictorial view of the modified tractor groundnut digger/shaker

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Fig.3: Pictorial view of the modified drawn groundnut digger/shaker in operation