Indoor Soil Bin Research Articles

A device for mechanical remediation of degraded grasslands

Conventional tillage practices are traditional methods to restore the degraded grasslands. However, the risk of wind and water erosion increases dramatically. To remedy these degraded grasslands and conserve soil and water, a rotary cutting mechanism named soil-gashing and root-cutting device was designed and tested in typical degraded grassland. The grass specie was leymus-chinensis, which is the main forage in Northern China. This device consisted of eight sets of cutting tools, and each set of tools had three identical crescent cutting blades. It can create consecutive openings in compacted soil. These openings provided soil aeration and promoted the growth of leymus-chinensis. Field experiments indicated that the maximum cutting depth was 200 mm while the average width of slits was 12.8 mm. No soil overturning was observed. To reduce the torque required to drive this cutting mechanism, the crescent cutting blade was optimized through indoor soil bin tests. Field tests were then conducted to evaluate the effect of this cutting mechanism on the soil physical and chemical properties and the crop yield of a degraded grassland. Results showed that soil organic matter and total nitrogen were significantly increased in the second year of soil-gashing and root-cutting treatment, and the soil pH value was reduced to the suitable level for the growth of leymus-chinensis. The soil bulk density was reduced, and the soil porosity increased after a one-year period though these changes were not statistically significant. Grass yield was increased by 94.8% in the second year.

Effects of bionic non-smooth surface on reducing soil resistance to disc ploughing

Past researches have shown that the non-smooth body surfaces of soil burrowing animals help to reduce soil resistance. In this research, this concept of bionic non-smooth surface was applied to disc ploughs and an experiment was conducted in an indoor soil bin to find out the effects of different bionic units on reducing soil resistance to disc ploughing. Horizontal force acting on the disc plough during soil deformation was measured using a 5 kN sensor. Convex and concave bionic units were used and the material used for making convex ones is ultra high molecular weight polyethylene (UHMWPE) which is hydrophobic. From the experiment results, higher or deeper bionic units always resulted in less soil resistance. Convex bionic units gave the highest resistance reduction reaching a maximum of 19% reduction (from 1715.36 N to 1383.65 N) compared to concave bionic units. Also, samples with a bionic unit density of 30% gave the highest resistance reduction compared to the other two, which were either plain or had 10% density. In conclusion, the concept of bionic non-smooth units can be applied to disc ploughs in order to reduce soil resistance.

Development of Overhead Gantry as Complementary Equipment to Indoor Soil Bin Facility

Development of Overhead Gantry as Complementary Equipment to Indoor Soil Bin Facility

Capillary Zone from a Watertable

An artificial perched watertable was constructed by a watertable construction machine at about 0.5 m depth from the soil surface in an area where the annual precipitation occurs only in the summer season to retain summer runoff in this watertable. The zone of capillary diffusion from the underground watertable during dry season for seven months from September to March in which no rain occurs was determined in an indoor soil bin which had a transparent side and a float and needle system to maintain water at a constant level. The results showed that water proceeded quickly into a whole sand layer and then into a clay soil layer. When the capillarity diffused into three-dimensional clay soil layer, the maximum length of the capillarity was 4.1 m in horizontal direction and the minimum length was 0.95 m in vertical direction for the seven months. Hence, the distance required to operate the watertable construction machine was 11.2 m.

Optimization and evaluation of rotary tiller blades: Computer solution of mathematical relations

Abstract Rotary tiller blades are used to achieve advantages of lower draft requirement, better soil breakup and more efficient inversion and trash mixing. Since these blades are fabricated in different shapes and dimensions by local manufacturers, this study was aimed at development of three types of rotary blades (namely, C-type, L-type, and RC-type) in order to reduce the energy requirement for tillage by optimizing the parameters which affect the cutting force of the rotary blades. For this reason the mathematical model of power requirement of the rotary blades and the equations of surface area per unit volume of soil tilled as well as cutting angle were determined and computer programs to solve those equations were developed. From the results of computer programs, blade geometrical dimensions corresponding to the minimum and optimum blade surface area per unit volume of soil tilled and cutting angle were selected to fabricate the rotary blades. The validity of the model for prediction of power requirement was checked via experiments conducted in indoor soil bin by measuring electrical power needed for rotating blades. The variation between experimental and prediction values ranged from −6% to +3.1%. Fabricated blades were also evaluated on the basis of specific work requirement in various numbers of blades per flange, forward speed and rotor speed. Specific work had an exponential relation with bite length, whereas linear relationship was observed with velocity ratio for all the blades tested. RC-type blade with less specific work requirement and more volume of soil tilled, had better performance than other blades.

DEVELOPMENT OF A VACUUM PRECISION SEEDER PROTOTYPE FOR ONION SEEDS

The purpose of this study was to develop, construct and test a vacuum precision seeder prototype suitable for onion seeds. The developed prototype was fabricated from local materials (Stainless Steel 304). It was also designed to plant two rows with 70 mm apart instead of one row as the most onion vacuum seeders in the market. Tests were conducted at an indoor soil bin facility under different operational parameters. These parameters were three seed plates with different hole diameters (0.8, 1.0 and 1.2 mm), four levels of disc speeds (peripheral velocity of seed plate) (0.08 (7.3), 0.14 (12.5), 0.21 (18.7) and 0.28 m/s (24.4-rpm)), four levels of blower speeds (4000, 4500, 5000 and 5500-rpm) and three level of forward speeds (2.7, 3.6 and 5.3 km/h). Measurements were taken for the actual seed spacing, seed miss index, seed multiple index, quality of feed index, precision in spacing and the vacuum pressure in the hole. Results indicated that the optimum values of the actual seed spacing (5.93 mm), seed miss index (8.1%), seed multiple index (8.12%), quality of feed index (83.7%), precision in spacing (23.4%) and the vacuum pressure in the hole (4.75 kPa.) were obtained with the seed plate of 1.0 mm hole diameter. Results of statistical analysis showed that the most desirable conditions in terms of operating developed prototype were obtained with the seed plate of 1.0 mm hole diameter at 0.21 m/s (18.7-rpm) disc speed, 4500-rpm blower speed and at 3.6 km/h forward speed. It also indicated that there was no appreciable difference between the two rows of the developed prototype under different operational conditions.

Development of a tyre traction testing facility

An experimental setup comprising up of an indoor soil bin, a single wheel tester (SWT), a soil processing trolley, a drawbar pull loading device and an instrumentation unit was developed to perform traction tests in the soil bin to study the effect of soil, tyre and system parameters on the performance of tyres. The design of the single wheel tester was such that the dynamic weight reaction force is equal to that measured statically. It is a simple wheeled device, capable of testing tyres of up to 1.5 m in diameter, vertical force up to 19 kN, net pull up to 7.2 kN, torque up to 5.5 kN m, and speed up to 3.5 km/h.

Performance prediction of animal drawn vehicle tyres in sand

Four animal drawn vehicle (ADV) tyres of 5.00–19, 6.00–19, 7.00–19 and 8.00–19 sizes were tested in sand under various but controlled conditions in an indoor soil bin. A tyre test carriage with four-bar parallel linkage was developed for accommodating a single wheel of different sizes. Performance tests were conducted at five levels of inflation pressure and load. The sand compaction level was varied in the range of 3.4–4.5 MPa/m and forward speed of the test carriage was maintained at 3.1 km/h. Performance of the tyres 7.00–19 and 8.00–19 was identical and offered less rolling resistance as compared to other tyres. However, their use in camel carts may not be recommended beyond the payload of 6 kN on single wheel with inflation pressure and sand compaction range of 172–379 kPa and 3.4 –4.5 MPa/m, respectively. Based on the experimental results, empirical models were developed to predict the performance of tyres. The accuracy of prediction of the developed empirical models was compared with that of existing semi-empirical approaches. Model with sand mobility number considered relatively simple and convenient to use in the field and yields reasonably good prediction for rolling resistance and sinkage.

Bionic optimization research of soil cultivating component design

The basic biomechanical laws that apply to the clawed toes of animals with powerful digging abilities and the optimal bionic design of curved soil cultivating components with an analogous contour were researched in a novel way. First, the curvature and profile of the inside contour line of a field mouse’s clawed toe were analyzed. The finite element method (FEM) was then used to simulate the working process in order to study the changing characteristics of the working resistance of bionic soil-engaging surfaces and the stress field of the processed soil. A straight-line cultivating component was used for comparative analysis. In accordance with the simulation results, a series of soil cultivating components of varying design were manufactured. An indoor soil bin experiment was carried out to measure their working resistance and validate the results of the FEM analysis. The results of this research would have important values in the optimization design of cultivating components for energy and cost savings.

Steady-State Models for the Movement of Soil and Straw During Tillage with a Single Sweep

A concept of steady-state movement, which mathematically describes the amount of soil and straw moving by a sweep, is proposed. A sweep model for the steady-state movement of soil and straw in front of a sweep was developed and validated by an experiment conducted in an indoor soil bin using three different lengths of oat straw and a 325 mm wide sweep. Existing soil-cutting models were also applied to the development of steady-state models. A three-dimensional model based on an earlier model model was developed for narrow tools; and a two-dimensional model originally proposed for earthmoving machines was developed for wide tools. The results of a validation exercise indicated that these steady-state models would predict the amount of soil and straw moving during tillage with a sweep even though the sweep was a wide tool at the tillage depth of 100 mm. However, the three-dimensional model and the two-dimensional model highly overestimated the amount of straw moving by a sweep. A possible reason was that the three-dimensional model was based on a model that was developed for a narrow blade but not a sweep. The sweep model proposed in this study provided the best results among these three models considering predicting both soil and straw moving zones. The relative error of the sweep model was 22% or less when predicting the amount of soil moving, and less than 12% when predicting the amount of straw moving. Application of existing soil-cutting models to the steady-state movement of soil and straw needs further study.

Draft Requirement of a Shovel Type Furrow Opener under Coarse Textured Soil Condition

A 55 mm shovel type furrow opener of combined seed drill was selected for optimization of its design parameters. Four boot wedge angles (20,40,60 and 80 degree) and four rake angles (30, 40, 50 and 60 degree) of the furrow opener were investigated at four operating depths (40, 60, 80 and 100 mm). The tests were conducted in a factorial randomized block design with two replications under sandy loam and loamy sand soil conditions in an indoor soil bin for optimizing the design parameters of the furrow opener in order to minimize its draft requirement. Boot wedge as well as rake angle of40° was found as the optimum value under both the soil conditions. Multiple regression equations were also developed to predict the draft requirements precisely under sandy loam and loamy sand soil conditions.

Soil Movement resulting from Sweep Type Liquid Manure Injection Tools

Knowledge of soil movement is important for the design and selection of injection tool to minimise agronomic and environmental concerns associated with liquid manure injection. Laboratory studies were conducted in an indoor soil bin to investigate soil movement in three directions resulting from sweep type injection tools. The first study was carried out to select point tracers. Three tracer sizes (10, 15 and 20 mm) and four tracer materials [wood, polyvinyl chloride (PVC), aluminium and steel] were tested for measurements of soil movement resulting from a sweep at constant injection depth and tool forward speed. The test results led to the selection of the 10 mm PVC tracers for the subsequent soil movement study. In the soil movement study, three sweeps (small, medium and large) were tested at three injection depths (50, 100 and 150 mm), two tool forward speeds (0·6 and 1·4 m s−1), and two soil moisture contents (14 and 18%). The selected tracers were used to measure soil movement in forward, upward and lateral directions. Increasing injection depth from 50 to 150 resulted in a 39% increase in the soil forward movement and a 37% increase in the upward movement. The higher tool forward speed produced a 31% higher forward movement and a 56% higher lateral movement. The higher soil moisture content increased the soil upward movement by 17%. The large sweep resulted in a 27 and 48% greater forward movement than the medium and small sweeps, respectively.

A LIQUID MANURE INJECTION TOOL ADAPTED TO DIFFERENT SOIL CONDITIONS

Injection of liquid manure into soil can reduce nutrient loss through volatilization, reduce odor emission, reduce surface runoff pollution, and increase plant uptake of nutrients. A liquid manure injection tool was developed based on the following design criteria: easy adaptation, low draft force and surface exposure of injected manure, and suitability for different soil conditions and for variable manure application rates. The tool featured a chisel with a sweep and a shank. The first prototype was tested using swine manure in a field with clay soil and wheat stubble to examine the draft forces and the resultant manure exposure indices under different injection depths and manure application rates. Based on the field test results of the first prototype, a second prototype was designed with a narrower tool cutting width and a smaller rake angle, and was compared with the first prototype in an indoor soil bin (loamy sand soil and no residue cover). The tool geometry and features implemented in the design met the proposed design criteria. The second prototype required lower draft force and caused less soil disturbance when compared with existing injection tools reported in the literature.

Laboratory investigation of cutting forces and soil disturbance resulting from different manure incorporation tools in a loamy sand soil

Injection of manure is becoming more popular than surface spreading due to its agronomical and environmental benefits. In this study, four different existing tools (two sweep types and two disc types) for liquid manure incorporation were tested in an indoor soil bin located in the Department of Biosystems Engineering at the University of Manitoba with loamy sand, to investigate the effects of working depth (50, 100 and 150 mm) and speed (0.57 and 1.4 m/s) on soil cutting forces and soil disturbance. Draft forces and soil disturbance for all tools significantly increased with working depth, but not with working speed. Owing to its wider soil cutting width, sweep B required 80% more draft force than sweep A. For the same reason, sweep B disturbed a 44% wider soil surface along the tool passage, compared to sweep A. On the average, sweep type tools created 27% new soil pores, which would be available for containing injected manure. For the discs, vertical forces decreased with increased working depth. As compared with disc A, wider surface disturbances along the tool passage were observed for disc B due to its two concave disc design. Comparing soil disturbance for different depths, disc B may not be suitable for manure incorporation at shallow depths (50 and 100 mm). At greater depths (150 mm) both disc-type tools will favor manure coverage.

Soil bin for model studies on tillage tools & traction devices

The variable and irreproducible nature of field soils has limited the success of most field studies on tillage tools, earth moving equipment and traction devices for off-highway vehicles. For this reason, the Agricultural Engineering Department of the University of Illinois has undertaken the investigation of these areas by using an indoor soil bin. The purpose of this paper is to explain the construction and operation of the soil bin along with its associated equipment. The first experimental results using the soil bin for testing model tillage tools are to be published in the near future.