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Open Access
Development and field evaluation of a cardomom polishing machine
(Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1999) Anu, Ray Mathew; KAU; Mohammad, C P
Cardamom capsules when dried have a dried flower stalk which is hard to be removed by manual operation. For destalkinq, a power operated cardamom polishing machine was developed, tested and its performance was evaluated. A polishing drum with attached wooden blades seperated the dried capsules fed in. from the flower stalk attached and were collected seperately. A single phase 1 hp motor served as power source. A 3-factlJr, factorial experiment in Completely Randomized Design (CRD) with drum speed, feed/batch, and retention time as independent variables was performed.
Open Access
Design, fabrication and testing of a power operated paddy dibbler
(Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1996) Jayarajan, R; KAU; Jippu, Jacob
A 2-row power operated paddy dibbler was designed, fabricated and tested at Kelapaji College of Agricultural Engineering and Technology, Thavanur. The main components of the dibbler were two seed boxes, plungers reciprocating within the seed tubes, fluted roller seed metering mechanism, dibbler wheels, stationary cam, frame and transport wheels. The seed tubes were fixed radially around the dibbler wheel with 45 mm of it projecting outwards for penetrating the soil. The plunger was actuated by a stationary cam and during its upward stroke it uncovered the farther end of the seed transfer tube and transferred the seeds into the seed tube and then into the holes made in the soil. In the downward stroke the plunger closed the seed transfer tube. Simultaneously the fluted roller transferred the seeds in to the seed transfer tube. The average speed of operation of the dibbler was 1.32 kmph and its field capacity and field efficiency were 0.031 ha/h and 78.18 per cent respectively. The average number of seeds dropped per hill was 5 and the seed rate obtained was 78 kg/ha. The seeds were placed within the confines of the holes made by the seed tube and plunger. There was absolutely no scattering. The depth of placement varied from 3.8 to 4.6 cm. The operating cost of the dibbler was Rs. 502.58/ha. This mechanism offers scope for developing dibblers with more number of rows for being operated more economically.
Open Access
Evaluation of low-cost lining materials for field channels
(Department of Land and Water Resources and Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2000) Abdu, Mudesir Issa; KAU; Reema, K P
Seepage losses from field channels are too high, making surface irrigation the inefficient method of water application. The high cost of lining hindered the use of most of the common lining materials for lining field channels. With an objective of identifying and testing low cost lining materials for field channels, a study was conducted at K.C.A.E.T., Tavanur. Four low-cost materials were tested in the experiments. The physical property tests on different RHA-cement types showed that the waterpercentages required to attain standard consistency of the RHA-cements ranged between 58.33 to 58.53. The mean initial setting times observed were ranging from 55.67 min, for RHA-20, to 241.39 min., for RHA-40. The final setting times ranged between 397.74 and 600.36 min. The compressive strengths of the RHA-cement made mortars were determined after 3, 7, 14, and 28 days of curing. The two factor analyses of variance revealed that both the days of curing and RHA-cement types were sources of variation. RHA-20 mortars were significantly weaker than RHA-25 and RHA-30 mortars for 7 days of curing, and for 14 and 28 days of curing a significant difference in the compressive strengths ofRHA-20 and RHA-30 was observed. The average seepage rates were obtained as 3.536, 92.786, 356.278, 26.190 and 633.296 Vm2/day for plastic, RHA-30, Kaolinitic clay, Bentonite lined and the unlined channels respectively. The respective steady seepage rates from plastic, RHA-30, Kaolinitic clay, Bentonite lined and the unlined channels were 0.984, 72.283, 260.256, 12.530 and 433.886 Vm2/day. Plastic lining saved 99.774 per cent of the seepage as compared le. ti:,unlined. RHA-20, RHA.:.25, and RHA-40 linings respectively were having steady seepage rates of 150.917,11.959, 101.161 lIm2/day and saved 65.377, 74.315, and 76.792 of the seepage against the control.The RHA-30 lined surface was the smoothest with a roughness coefficient of 0.01853, the same were 0.0236, 0.0255, 0.02497 and 0.0238 respectively for plastic, Kaolinitic clay, Bentonite and unlined surfaces. The total number of weeds grown on plastic, RHA-30, Kaolinitic clay, Bentonite and unlined surfaces respectively were 294, 7, 287, 163,and 547. The initial costs of constructing I Km length of field channel were obtained as Rs.54657.86, 83008.84, 68062.50, 81490.31 and 21000.00 for plastic, RHA-30, Kaolinitic clay, Bentonite and unlined channels respectively. The actual cost required to construct the five 10 m channels with plastic, RHA-30, Kaolinitic clay, Bentonite linings and with out lining respectively were Rs. 548.40, 832.15, 618.45, 1330.08 and 210.00. From the overall compansons of water tightness" surface roughness, weed controlling ability, structural stability, durability and cost RHA-30 lining was found to be the best among the tested lining materials. A combination type lining using plastic and RHA-cement as a cover will probably be an ideal lining, as each can complement the shortcomings of the other.
Open Access
Optimal number and discharge rate of emitters for coconut palm in sandy loam soil
(Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2000) Priya Nair, G; KAU; Suseela, P
AgricullurClI productivity is based on the availability of required water at proper time. As water is becoming Cl limited resource its efficient utilization is very essential. The distribution of rainfall in Kcrala is not adequate to meet the total welter requirement of coconut. Coconut in Kerala are mostly grown in sandy soils which has a poor water holding capacity. So drip irrigation is the best method of irriqation for coconut in this soil. The efficient design of drip irrigation system involves the optimal spacing of emitters, correct discharge rate anr' duration of inigc\lion based on the movement of soil moisture front. So the study of moisture distribution pattern under chip irriU(ltion is helpful in deciding optimum number and discharge rate of emitters and duration of irriqation required for coconut palms The study was conducted in the river side coconut gc)rdr.n of the instruclional Farm, I~CAET, TaVilrH1I. The size of the plot was 28x63m. The soil properties viz texture. bulk dcn-itv. infiltration rate, field capacity. hydraulic conductivity and permanent \vi!;JI1q point were observed. The drip system was installed in the fielc! Two different c!ischarge rates (4 and 8lph) and three f combination of number of emitters (3,<'1 & 6) were selected for the study. The maximum vertical and horizontal advance of soil moisture front for both the discharge rates (4 and 8 Iph) were noted. Empirical equations were also developed for both vertical and horizontal advance. The soil moisture contents were determined at different horizontal anc! vertical distances from the emitter, before irriqation, 1 hour, 24 hours and 3 days after irrigation by gravimetric method. The soil moisture contour maps were plotted and the moisture distribution efficiency was calculated for each treatment at all depths. The maximum vertical and horizontal advance was observed for 8 lph emitter compared to 4 Iph emitter. The welting front from a single emitter produced C\ bulb like \Netting pattern for both the discharges. The size of the wetting bulb increased with increase in discharge rate. The study revealed that 4 numbers of 8 Iph emitters give more uniform distribution compared to all the other treatments.
Open Access
Optimization of greenhouse ventilation for humid tropics
(Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2000) Jinu, A; KAU; Abdul Hakkim, V M
In any agricultural sector, the need of the hour is to maximize the yield per unit area to cater the needs of our population, which is exploding at an alarming rate. Protected cultivation or controlled environment agriculture is one of the methods to increase the crop production from unit area. Of the various forms of protected cultivation, greenhouses are most common. Our state falls under humid tropical climatic condition. Greenhouse cooling is to be done during peak hours of daytime under this climatic condition. Ventilation plays an important role in green house cooling. A study was conducted to determine the optimum greenhouse ventilation for humid tropics and to analyze the effect of different cooling methods viz. natural ventilation, fan and pad system, mist system and roof shading on greenhouse cooling. The study showed that natural ventilation could reduce the greenhouse temperature to a great extent. The different percentages of ventilation used for the experiment were 13.8, 11.5, 9.2, 6.9, 4.6 and 2.3. The study was also conducted without ventilation. As percentage ventilation increases, greenhouse cooling increases and inside relative humidity decreases. 13.8 percent ventilation gave maximum greenhouse cooling and this value is taken as the optimum percentage of natural ventilation. But the natural ventilation alone cannot meet the cooling requirement during peak hours. Fan and pad system is found to be not effective for greenhouse cooling in this particular study. Even 2.3 percentage of natural ventilation condition gave better cooling than fan and pad cooling system. Misting is an effective method to lower down the greenhouse temperature within a short period of time. Misting was done along with fans at different percentages of ventilation and the different climatic parameters were studied. The results showed that while misting, the maximum cooling was obtained at 2.3 percent of ventilation. Effect of roof shading on greenhouse cooling was tested with one shade net over the greenhouse. Roof shade has a significant effect on greenhouse cooling. Th inside temperature of the greenhouse was higher than the outside temperature by more than lOoe during peak hours of the day time, when no ventilation was provided and fan and pad system, mist system and shade cover were not used. But when the green house was covered with a shade net, an inside to outside temperature difference of one or two degree was observed. Also, while operating fan and pad system and mist system, shaded condition gave better cooling. Fan and pad system operated without shade cover, could not bring down the greenhouse temperature below ambient temperature. But for the shaded condition, greenhouse temperature could be lowered to a value less than the ambient temperature. Misting under shaded condition at 2.3 percent ventilation gave maximum cooling. Misting inside an unshaded greenhouse at 2.3 percent ventilation could bring down the greenhouse temperature to 32°C, but misting inside a shaded greenhouse at 2.3 percent ventilation lowered the greenhouse temperature to 29°C. Use of two shade net layers did not give any additional cooling, and at this condition the light intensity inside the greenhouse was only 10 percent of the outside light intensity. It only increases the cost of the greenhouse and hence it is not recommended to use two shade net layers for greenhouses.
Open Access
Erodibility and runoff potential of laterite soils under simulated rainfall conditions
(Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1999) Sajeena, S; KAU; Kurien, E K
Soil erosion is one of the most serious environment degradation problems. However reliable measurement of erosion remains limited and estimates of soil productivity are even rarer. Assessing the extent and seriousness of erosion therefore remains a difficult task Nevertheless, identification and assessment of erosion problems could have an important role in influencing better land use and conservation practices. Rainfall simulators are considered as an effective tool in soil conservation research. Simulators make it possible to produce predetermined storms at any desired time and location. They make the replication of research easier and facilitate the study of storm sequences. Laterite soils are by far the most important soil group occurring in Kerala and cover the largest area. The objective of this study was to estimate the erodibility and runoff potential of laterite soils of three well defined series under simulated rainfall conditions. The rainfall simulator designed and fabricated by Kurien and George (1998) was modified for better performance. The modified simulator could produce rainfall intensities varying from 741 to 23.00 cmlh. Also uniformity of the rainfall produced could be increased to higher values of 88.10 and 91.53 per cent, thus giving a better performance. Intensity of rainfall increased as the 11 pressure of supply water to the simulator increased and a relationship was established between intensity and the supply pressure of water as 1= -87.205 p2 + 108.61 P - 10.786 (R = 0.99) Experiments were also conducted to study soil loss and runoff from three different series of laterite soils, i.e.Mannamkulam series, Naduvattom series and Vellanikkara series. The soil loss and runoff increased with increase in the rainfall intensity for all slopes studied for each series of soil. A general trend of increase In soil loss and runoff with increase in the slope was observed for all the three series of soils. Empirical equations were developed for estimating soil loss (E) and runoff (0) for various intensities of rainfall and land slopes for the three series of soils selected for the study. The equations are: Mannamkulam series E = 1167.797 I + 835.109 S - 21686.07 (R = 0.90) Q = 65.0161 + 16.747 S - 235.923 (R = 0.99) Naduvattom series E = 324.766 I + 112.799 S - 3912.219 (R = 0.97) Q = 74.542 1+19.434 S - 394.323 (R = 0.99) Vellanikkara series E = 115.662 I + 431. 064 S - 11512.284 (R = 0.98) Q = 58.742 I + 26.837 S - 310.019 (R = 0.99) ii1
Open Access
Performance evaluation of high discharge low head pumps
(Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1998) Rini Rani, S; KAU; John Thomas, K
Paddy cultivation in Kuttanad and Kole lands is made possible only after large scale dewatering operations. These water logged lands have to be drained in the shortest possible time to initiate seed bed preparation. The short time available for seed bed preparation need adoption of high discharge low head pumps. The most commonly used centrifugal pump is incapable of giving corresponding increase in discharge rate even if the lift required is reduced to a minimum. So this study was undertaken to help to identify a suitable portable pump for meeting the specific requirement of drainage in Kerala. Mixed flow and axial flow pumps imported from Thailand were used for this purpose. The study included testing of lS-cm mixed and axial flow pump at the specially designed and constructed test bed at different speeds and at different water levels in the pumping sump. For each test, from the data obtained discharge, input power and efficiency were calculated. Using the calculated values performance characteristic curves were plotted and regression equations were developed for discharge efficiency, discharge - total head and discharge - input power relationship at each speed. Performance curves were also plotted keeping total static head const ant and regression equations of speed - discharge, speed - total head, speed - input power and speed efficiency relationships were developed. The maximum efficiency of IS-cm mixed flow pump was 42.16 per cent at a speed of 1000 rev/min, against a total head of 217.33 cm and a discharge rate of 49.47 L/s. The input power corresponding to this efficiency was 3.4 hp. The best performance of mixed flow pump was noted at a working speed of 1000 rev/min. The maximum efficiency of IS-cm axial flow pump tested was only 18.05 per cent at a total head of 160.55 cm and a discharge of 24.88 L/s. The corresponding speed was 2500 rev/min and input power was 2.95 hp. The best performance of axial flow pump was noted at a working speed of 2500 rev/min.
Open Access
Effect of soil solarization using ldpemulch on moisture conservation and soil temperature variation
(Department of Land and Water Resources and Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1997) Anu Varghese; KAU; John Thomas, K
Soil solarization is based on mulching the soil surface with transparent polyethylene sheets which capture the solar radiation and thus heat the soil to a level lethal for various pests. Solarization is useful in the control of weeds and also helps in moisture conservation. To some extent this can satisfy the demand of water for pre sowing irrigation during the summer months by conserving the moisture in the soil. In the experiment two types of polyethylene sheets (0.10 mm and 0.05 mm) were used and three durations of solarization, i.e., 30 days, 40 days and 50 days were tried. A crop (bhindi) was sown in the area after the solarization period to know the effect of solarization on its performance. The average maximum soil temperature at 5 cm depth obtained in the non-solarized plots was 49.5°C only, but in solarized plots it went upto 56.5°C. The magnitude of rise in soil temperature of solarized treatments was higher due to 0.05 TP than 0.10 TP. The intensity of solar radiation reaching the soil surface was significantly higher in the non-solarized plots than in the solarized plots. There was significant increase in the moisture content values in the solarized plots compared to the non solarized plots at 5, 10 and 15 cm depth below the soil surface. The moisture content values in 0.05 TP solarized plots were slightly higher than in 0.10 TP solarized plots, but was not significant. In the solarized treatments, there was 37.9, 33.7 and 38.3 per cent increase in the moisture content values at 5, 10 and 15 cm depths respectively. Solarization also had significant effect in lowering the weed count as well as the dry weight of the weeds for around 5 months after the period of solarization. The yield of bhindi was significantly higher in the solarized treatments than in the non-solarized treatments. This increase in the yield of bhindi may be due to the drastic reduction in weed count and dry weight on account of solarization.
Open Access
Dynamics of power transmission in tractor mounted paddy reaper
(Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1996) Sushilendra; KAU; Sivaswami, M
A tractor front mounted 2.2 m wide paddy reaper windrower was evaluated to find out the optimum forward speed, cutterbar speed, conveyor belt speed and engine speed for different field conditions to achieve better harvesting and windrowing pattern, Maximum field capacity and field efficiency with less harvesting losses. Three PTO pulleys of 17.78 cm, 19.03 cm and 20.32 cm diameter with internal splines were fabricated and used with an engine speed from 1000 to 2000 rpm with four gears in low range and first gear in high range. In addition to pneumatic tyres, a pair of special cage wheels and a simple collection unit were developed and evaluated. In water submerged fields with special cage wheels and PTO pulley of 17.78 cm diameter better results were observed when reaper was operated at an engine speed of 1500 rpm with third low gear with a forward speed of 0.95 m/s. The optimum cutterbar index and conveyor index were found to be 1.56 and 2.30 respectively. The actual field capacity was 0.38 ha/hr and field efficiency was 54 per cent. The crops were found to throw within 10 cm from the discharge plate with an tiller angle of more than 85 degree with only 1.54 per cent of total loss of grain. When the soil is moist and pneumatic wheels fail to give sufficient traction, the special cage wheels were used with a PTO pulley of 19.03 cm diameter. An engine speed of 1400 rpm with third gear and with a forward speed 0.90 m/s was found to give satisfactory performance. The optimum cutterbar index was 1.66 and conveyor index was 2.45. The reaper had the field capacity of 0.36 ha/hr with field efficiency of 53 per cent. The windrowed crop were found to throw within a distance of 13.5 cm with 85 degree of tillers angle with total grin loss of 1.55 per cent. For dry fields, the reaper with pneumatic wheels was found to operate satisfactorily with 20.32 cm diameter PTO pulley at an engine speed of 1300 rpm with fourth gear and with a forward speed of 1.00 m/s. The optimum cutterbar index was 1.48 and conveyor index was 2.19. The actual field capacity was 0.38 ha/hr and field efficiency was 50.66 per cent. The tillers angle was 85 degrees with total grain loss of 1.62 per cent. It is found that the better field performance was achieved when the reaper is operated at a cutterbar speed of 1.50 m/s and conveyor belt speed of 2.20 m/s. A simple crop collection unit of size 1. 5m x 0.7m x 0.35m was developed with the provision for conveying the windrowed crop directly into the collection box. The unit was field evaluated with reaper. The box was found to fill within 10 m of travel and problems were observed in its manoeuv reability, loading and unloading of box and increased idle time.

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