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In the present work, it is analyzed the behavior of the cutting forces (draft force and vertical force)of a vibrating subsoiler tilling a silt loam soil (ferralitic), by a soil-tillage interaction simulation model, developed applying the Finite Element Model and using the elastoplastic Drucker-Prager constitutive model and Solid Works design software. The soil parameters and properties required for simulation, the boundary conditions and acting loads were assigned to model and the meshing of the model was realized. Several running of the model were also realized for four forward speeds (0 ms-1; 0, 4 ms-1; 0, 8 ms-1 and 1, 2 ms-1). The results showed the quadratic behavior of both forces with the increasing of forward speed. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effects of a locally manufactured combined tillage machine on the draft force, fuel consumption, field efficiency, power loss, and soil pulverization index. The combined tillage machine accomplished the primary, secondary, and deep tillage in a single pass. The combined tillage machine types were compared to individual tillage machines. The combined tillage machine accomplished the primary, secondary, and deep tillage in a single pass. A randomized complete block (RCBD) experiment was the statistical method used for the investigation with three replicates. The field experiments were conducted in silty loam soil. The combined tillage machines were used in three types. The first configuration (T1) consists of a subsoiler+ chisel plow + disk harrow + roller, the second configuration (T2) consists of a subsoiler + chisel plow, and the third configuration (T3) consists of chisel plow + disc harrow at two operating speeds (1.5 and 3 km.h-1). Individual tillage machines were used in three conventional tillage systems M1, M2, and M3. M1. Conventional tillage systems M1, M2, and M3 perform similar tasks to combined tillage machine types T1, T2, and T3 respectively. The results showed that T3 reduced draft force by 40 and 34.35%, saved fuel by 19.88 and 25.89%, and reduced power loss by 54.25 and 37.22%, while increasing field efficiency by 13.64 and 5.63 and the soil pulverization index by 26.67 and 66.24% compared with T1 and T2 respectively. The combined tillage machinesT1, T2, and T3 reduced the draft force and power loss while increasing the field efficiency by 19.05, 22.41, and 53.49%, respectively, compared with conventional tillage systems M1, M2, and M3. The combined tillage machinesT1, T2, and T3 achieved the lowest values of the soil pulverization index, with values of 19.91, 41.93, and 33.10 mm, and saved fuel by 58.68, 41.61, and 26.86% respectively, compared with conventional tillage systems M1, M2, and M3. The results also revealed that operating speed and its interaction with the combined tillage machine types had a significant effect on all of the studied characteristics (p<0.05). [ABSTRACT FROM AUTHOR]

The experiment was performed using locally manufactured subsoiler plow provided with wings on the outside of shallow tines feet to study the impact of adding the wings and depth of tillage on the disturbance area of soil, soil pulverization index (mean weight diameter, MWD) and the equivalent energy of soil pulverization (Eq EP) in clay soil. This experiment was done in Randomized Complete Block Design (RCBD), with three replications having a factorial experiment. Three tillage depths (40, 50, and 60cm) with and without wings on the feet of shallow tines were used. The results showed that the impact of adding wings and tillage depths had a significant effect on the disturbance area, soil pulverization index and the equivalent energy of soil pulverization (p < 0.05). The treatment of adding wings on shallow tines (S+shw) has pre-eminence in studied factors. The disturbed area increased by 11.11, 14.29 and 9.80%, the MWD decreased by 27.33, 32.31 and 19.38% and the Eq EP increased by 43.19, 53.03 and 25.13% when the depth of tillage increased from 40, 50 and 60cm respectively. [ABSTRACT FROM AUTHOR]

Soil compaction is common problem facing conservation fields that restricts crop roots growth and causes yield decrease. Subsoil techniques have been developed to break up the compaction layer. However, subsoil implement require large draft power that hampered the development of subsoil techniques for the most of developing countries due to lack of large scale tractors. Aiming to optimize the penetration resistance of the subsoiler and create a good working environment for the operators, a staggered vibrating subsoiler was developed. A new staggered vibrating mechanism was designed to generate the staggered vibration of the shanks meanwhile the V-shape shanks arrangement was adopted to keep relative balance for the subsoiler. In order to obtain optimum working parameters of the vibration frequency and forward speed, the trajectory of shanks were simulated by the MATLAB software. The forward speed of 2-3 km/h with vibration frequency of 12 Hz was recommended to acquire effective decrease in draft force. Field performance of this subsoiler was evaluated in terms of the draft force, power requirement and tractor wheel slippage. By comparing the two operation modes, staggered vibrating (SV) and rigid (NV) of shanks, the decrease ratio of draft force for SV was determined by 16.97%, 12.12% and 9.02% at forward speed of 2.2 km/h, 2.6 km/h and 3.1 km/h respectively. This is better than the research for the 1SZ-460 vibratory subsoiler that decreased 9.09% in draft force. The power requirement for SV was not significantly greater than that for NV. The obviously decreased wheel slippage was observed for SV by decrease of 12.47%, 17.96% and 21.79% at forward speed of 2.2 km/h, 2.6 km/h and 3.1 km/h respectively. In conclusion, the staggered vibrating subsoiler presents preferable working performance and is recommended to be applied in subsoil tillage process for developing countries. [ABSTRACT FROM AUTHOR]

Equipping tines with the wings increases draft and soil loosening. Wing angles affect tine performance, soil aggregation and remained residue. In this research, conventional wing with no bent plus backward and forward bent wings with bend angles of 10 and 20° were attached to both a subsoiler and paraplow tine. The rake angle of all wings was 15°. The effects of tine and wing on draft, soil disturbance area, specific draft, remained residue, and mean weight diameter (MWD) were investigated in a clay loam soil at depth of 40 cm and speed of 1.6 km h−1. The effect of tine and wing plus interaction of them on all parameters was significant (p < 0.01) with the exception of remained residue. The bent-winged tines required higher draft and caused higher disturbance area, lower specific draft, and lower MWD than the conventional tines and those without wing. The highest draft, disturbed area and remained residue plus the lowest specific draft and MWD were obtained when applying the 10° forward bent-winged tines. In present work, the paraplow equipped with forward bent wings with a bend angle of 10° was suggested as a suitable tool for deep soil loosening under a conservation tillage system. [ABSTRACT FROM AUTHOR]

Four instrumented subsoilers were developed for alleviation of compaction on agricultural land. Draughts and soil disturbance of the subsoilers were measured during operation at the outdoor soil bin. Straight shank subsoiler (SSS), Straight shank subsoiler at 37o rake angle (SSS37), semi-parabolic subsoiler (SPS), parabolic 'C' shank subsoiler (CSS) and winged subsoiler (WSB) were designed and constructed for use by the tool carrier in loosening soil hard pan. Soil cone penetrometer (CP40II, 333 mm³, 60° cone tip angle) and electronic moisture meter were used to take readings at various locations and depths on the soil bin before and after subsoiling. Soil samples were taken to laboratory for analysis for physico-chemical properties. Each of the shanks was hitched to the tool bar of the carrier. A 100 kN calibrated load cell was connected to the tool carrier via the drawbar of a 31.6 kW (MF 415) Massey Fergusson tractor. The load cell was connected to the data logger via instrumentation amplifier. Laptop computer system was connected to the data logger to download the draught data for each shank which was operated at four levels of depth -20, 30, 40 and 50 cm. Profilometer of dimension 80 by 75 cm height and width respectively was used to measure the area of soil disturbance by each subsoiler. Data collected were analyzed to establish relevant relationships between subsoiler draughts and tillage parameters in the form of correlation, regression models and graphs. Results showed that the best subsoiler in terms of draught reduction was parabolic C-shank subsoiler (CSS) with 4.581 kN, followed by semi-parabolic subsoiler (SPS) with draught of 4.905 kN at depth of 40 cm. At this working depth the SSS, WSB and SSS37 had draughts of 6.874, 7.003 and 7.385 kN respectively. Thus, WSB had the highest power requirement followed by straight shank subsoiler at 37o rake angle (SSS37), both had 34.09 and 31.20 kW at 50 cm depth respectively. Thus at 20 cm depth of operation WSB and SSS37 subsoilers had 13.95 and 14.29 kW respectively. CSS had the lowest power requirement followed by SPS with 5.55 and 7.76 kW respectively. Straight shank subsoiler at 37o rake angle, SSS37 showed the highest soil loosening ability at all the depths followed by WSB, SPS, SSS and CSS respectively. Thus, at 50 cm highest working depth SSS had 0.0451 m² followed by SPS with 0.0487 m², while CSS, WSB and SSS37 had 0.0403, 0.0683 and 0.1061 m² respectively. Regression equations were established for the draught of each subsoiler. They all had R2 of more than 99%. Draught of subsoilers had high positive correlation with depth, cone index (CI) and bulk density (BD), and negative correlation with soil moisture (MC) and porosity (PR). [ABSTRACT FROM AUTHOR]

Subsoiling is primary practice in conservation tillage fields, as it disrupts compacted soil hardpans that restrict crop root growth and water infiltration. Subsoiler with flexible tines presents effective obstacle avoidance and draft force reduction, but the undesired depths, much less than target value, are observed during tillage operation due to the considerable variation in soil resistance. Therefore, an electric-hydraulic control system for subsoiler with flexible tines was developed and a novel method for detecting tillage depth was described. The performance of the electric-hydraulic control system was evaluated in soil bin experiment by the detecting accuracy of the tillage depth and the operation quality (qualified index, distribution uniformity of tillage depths and draft force reduction). The detecting accuracy of the electric-hydraulic control system was determined at target depths of 25 and 30 cm, by testing tillage depths and comparing with manual measurement. The values obtained by the control system differed from manual measurements by less than 3.2% (3.2% at 25 cm; 1.9% at 30 cm), indicating high accuracy. The operation quality of the electric-hydraulic control system was evaluated for the working speeds of 1.4, 2.0, 2.6 km/h at target depth of 30 cm, by testing the tillage depth, draft force obtained with and without the electric-hydraulic control system. Treatments without the electric-hydraulic control system (CP) were five types of constant hydraulic pressure, respectively 2.0 MPa (CP 2.0), 2.5 MPa (CP 2.5), 3.0 MPa (CP 3.0), 3.5 MPa (CP 3.5) and 15 MPa (CP 15). Treatments with the electric-hydraulic control system (AP) were adjustable hydraulic pressure with the range of 2.0–3.5 MPa. Results indicate that flexible tine with AP created more regular cutting cross-section and acquired relatively consistent tillage depth. The qualified indexes of tillage depth ( QI ) were respectively 97.5%, 98.2%, and 96.7% at the forward speeds of 1.4, 2.0, 2.6 km/h. And mean tillage depths with AP were respectively 29.54, 29.53, 28.13 cm, closely to target depths. The distribution uniformity of tillage depth with AP was better than CP. Furthermore, draft force increased at the area with high soil resistance, flexible tines with AP experienced a relatively more stable rise and obtained draft force reduction of 18.17%, 18.35%, and 25.89% at three forward speeds. The results demonstrate that the developed system can be used to improving the tillage quality for subsoiler with flexible tines. [ABSTRACT FROM AUTHOR]

Successive years of mechanical operations and conservation tillage in Northeast China have made subsoiling necessary, and the tillage depth can be no less than 40 cm. In this paper, a bionic design method was used to reduce subsoiler energy consumption and soil disturbance. The bionic structural elements, i.e., triangular prism (BTP) and partial circular column (BPCC), were inspired by the placoid scale rib structure of shark skin, which has low drag. These elements were then applied to the subsoiler to reduce energy consumption. Six types of bionic subsoilers were designed. Discrete element modeling (DEM) was used to simulate and analyze the interactions of the bionic subsoilers and an ordinary subsoiler (O-S) with the soil. The results showed that bionic subsoilers with a shank and BTP in the horizontal direction of motion (S-T-H) and tines with the BTP parallel to the centerline (T-T) had lower draft requirements and energy consumption than the other designs. The draft requirements and energy consumption of S-T-H subsoilers with different height-to-lateral-rib-spacing ( h / s ) ratios were then compared. The subsoiler with a bionic element h / s of 0.57 (S-T-H-0.57) had a lower draft requirement (1292.59 N) and a lower total energy requirement (23.48 J) than the other designs. A soil disturbance analysis demonstrated that S-T-H-0.57-T-T (bionic elements arranged in both the shank and tine) provided superior benefits in terms of root growth and improved crop stress resistance. The result is consistent with the mechanical analysis of the riblet, which will be helpful for designing new subsoilers with reduced drag and soil disturbance. [ABSTRACT FROM AUTHOR]

Tine spacing is a key parameter for the design of a subsoiler and has a significant effect on soil disturbance, which is a critical performance indicator of subsoiling. In this study, a subsoiling model was developed using the discrete element method (DEM). A subsoiling experiment was also conducted in a field with a loamy clay soil to serve the model development and model validations. In both the simulation and experiment, two V-shaped subsoiling tines were investigated at five different tine spacings (300, 350, 400, 450, and 500 mm), a constant working speed (0.83 m s −1 ) and a constant working depth (300 mm). The results showed that the 400 mm tine spacing resulted in the highest particle forces in the middle and deep soil layers. The height of the unloosened soil between two adjacent subsoilers increased as tine spacing increased. When the tine spacing was varied from 300 to 500 mm, the undisturbed soil height was changed from 100 to 226 mm in the experiment, and from 79 to 170 mm in the modelling. When the tine spacing was 400 mm, the number of soil particles disturbed in the shallow soil layer accounted for 45.6% of the total soil particles disturbed, which was the least among all the tine spacings. Considering the characteristics of soil disturbance, the tine spacing of 400 mm appeared to outperform the other spacings. [ABSTRACT FROM AUTHOR]

The identification of the movement behaviour of soil in the area under the combined effect of two subsoilers (i.e., the area between two subsoilers) is one of the key issues in determining a reasonable inter-subsoiling shovel distance. The present study established a working model of subsoiling using the discrete element method (DEM). Based on this model and an indoor soil-bin experiment, the present study focused on investigating the micro-movement and macro-disturbed behaviour of soil in the area under the combined effect of two subsoilers. The results show the following. (1) The range of transverse and longitudinal disturbance of soil decreased with increasing distance between the soil and subsoiler. The range of disturbance of the soil in the shallow layer was the widest, followed by the range of disturbance of the soil in the middle layer and the range of disturbance of the soil in the deep layer. The simulated and experimental values of the mean displacement of the soil in the shallow layer (tracer blocks with a side length of 10 mm) were 34.81 mm and 34.55 mm, respectively (error: 0.75%). (2) The force on the soil particles in the deep layer was the greatest, followed by the force on the soil particles in the middle layer and the force on the soil particles in the shallow layer. The force on and the velocity of movement of the soil particles at different locations decreased with increasing distance between the soil and subsoiler. (3) The discrete element simulation could accurately simulate the disturbance process of the soil subjected to subsoiling. The sectional profiles of the disturbed soil obtained from the simulation and experiment were consistent with each other. The relative error between the simulated and experimental values of the soil looseness and the soil disturbance coefficient was 14.45% and 12.06%, respectively. Based on the DEM combined with an indoor soil-bin experiment, the present study determined the movement behaviour of the soil in the area under the combined effect of two subsoilers. The results of the present study can facilitate in-depth investigations of the subsoiling shovel–soil interaction and provide a basis for making decisions to optimise subsoiler arrangements. [ABSTRACT FROM AUTHOR]

In this study, the effect of tine type, adding wing, operating depth and forward speed on the draft requirement of subsoil tillage tines was investigated in clay loam soil. Three subsoil tillage tines (subsoiler, bentleg and paraplow), four levels of forward speed (1.8, 2.3, 2.9 and 3.5 km/h), three levels of depth (30, 40 and 50 cm) and winged and no-wing tines were examined with the exception of bentleg as it would not be winged. It was revealed that draft of the tines is less affected by forward speed but is much affected by tine type, depth and wing. It was observed that an increase of speed and depth plus adding wing results in an increase of draft in all tines. Additionally, it was found that in all depths and speeds, subsoiler required more draft than paraplow and paraplow required more draft than bentleg. Multiple regression models including the studied parameters were developed to predict the draft requirements for each tine with high accuracy. [ABSTRACT FROM AUTHOR]

The aim of this work was to evaluate an alternative to reduce energy consumption applied to primary soil tillage. To do this an experimental apparatus was developed to evaluate the operation of vibration induced tillage. The components that integrated the system for field valuation were: frame tool carrier that includes a system of three-point hitch and depth control mechanism; three sensors were included to measure tillage force, torque and the frequency of the subsoiler oscillation. Oscillatory impact force was applied through a rod and crank mechanism through a subsoiler tine whose movement is provided by a hydraulic motor. The apparatus evaluation was complemented by a system of data acquisition and signal conditioner that allows the registration of the variables of interests such as draft power, penetration force, applied torque and speed of oscillation of the system. The results of the calibration of the sensors showed a system correlation higher than 95%. The results obtained during field system verification at different speed, amplitude and depth of tillage showed a reduction of the draft force up to 50% using the oscillated induced tillage compared to the non-vibrating tine condition. The study shows a significant increase in the magnitude of the draft force and torque applied by 33% when the working depth increased from 0.30 to 0.40 m and an increase of 21% of draft force was produced when the amplitude of oscillation was reduced from 0.070 to 0.060 m. No significant difference was found when the tractor speed was increased from 1.5 to 2.5 km h-1. For future work the developed apparatus will allow to determine how the amplitude and the working depth and oscillation frequency of the tine could affect the draft force in tillage work. [ABSTRACT FROM AUTHOR]

Rake angle is a key parameter of subsoiler structural design and has important impacts on subsoiler performance. In this study, the high-speed photographic technique was used to understand the mechanisms by which the rake angle of an arrow subsoiler (angles of 18°, 23°, and 28°) impacted soil disturbance. The following results were obtained. (1) Rake angle was the main factor that influenced the soil disturbance process. Changing the rake angle could induce changes in the interactions between the subsoiler and soil, impacting soil disturbance performance. (2) Rake angle had significant impacts on the soil disturbance state. The horizontal soil disturbance distance increased and the vertical soil elevation decreased when the rake angle was increased. For a fixed soil loosening strip length, the soil disturbance resulting from a subsoiler rake angle of 23° was 1.14 and 1.03 times greater than the soil disturbance that resulted from rake angles of 18° and 28°, respectively. (3) The rake angle also had significant impacts on the soil disturbance results. When the rake angle was 28°, the subsoiler soil disturbance rates in the top 10 cm soil layer and the entire top soil layer were 92.89% and 99.13%, respectively, which were greater than when the rake angles were 18° and 23°. The rake angle of a subsoiler influenced the soil disturbance. An appropriate rake angle is critical to ensure a high-quality cultivation. This paper provides the information for making decisions regarding subsoiler design and structural parameter optimization. [ABSTRACT FROM AUTHOR]

There are problems that the tillage depth of subsoiler is adjusted artificially and state subsidies are defrauded in cultivating process. The tillage depth of deep loosening machine measuring system is designed for artificially adjusting tillage depth in order to reduce the tillage depth and obtain state subsidies. The hardware platform of the measuring is set up, and the related software and communication subsystem are developed. The angle between the forearm of the frame and the vertical direction before and after the subsoiler subsoiling soil using acceleration sensor detected, the calculation model of tillage depth is given, and then the actual depth is calculated through the internal model, the tillage depth data is transmitted through 3G network. Field tests were carried out, the practical application shows that the system can give the tillage depth in cultivated land process, and has a very good practical significance, popularization and application value. [ABSTRACT FROM AUTHOR]

Durability and wear-related geometry change of three constructional solutions of subsoiler shanks were determined in field conditions: a shank with no additional reinforcement (shank A) and elements reinforced by pad welding and with sintered carbide (WC) plates (shanks B and C). The wear phenomena were observed using SEM and EDS analysis. The study demonstrates the influence of design construction of the shanks to its durability. The durability of shank C, was over four times larger than other shanks. Limit state of elements A and B was determined by reduction of their length. In case of shanks B it was considered with the spalling of underwent plates, whereas the spalling of the carbide plates of shank C only took place sporadically. [ABSTRACT FROM AUTHOR]

Generally, a subsoiler is comprised of a shank and a point. The point shape has a significant effect on the draft force of a subsoiler. In this study, the draft force of subsoilers with four different points were compared under the speed of 0.8 m/s and the depth of 350 mm in the soil bin. Discrete Element Method (DEM) was applied in simulating the working process of the subsoiler. The stiffness of soil particles used in DEM was calibrated by comparing the simulated draft force of a standard arc-shaped subsoiler with the experiment. The calibrated soil particle stiffness was 1.1×104 N/m. The validated model was then used to compare the draft force of subsoilers with four different points under the same condition in the test. Results showed that different points would cause different draft forces. The subsoiler with short chisel point caused the smallest draft force (2885 N) while the point with short face and wings had the largest force (4474 N). The relative errors of the simulated results were less than 4%, which proved that DEM was an effective way for predicting the draft force of subsilers. The velocity field and contact force filed could show the movement of soil around the subsoiler. [ABSTRACT FROM AUTHOR]

Currently, rural technological development has emerged as a response to the need for improving production efficiency in the fields, especially in agricultural countries such as Colombia due to aspects such as demographic growth and economic globalization; the use of a subsoiler is the first activity performed, intended to loosen soil as a way of reducing its resistance and allowing the spread of plant roots and flow of water. Hence, any type of abnormal circumstances in the development of this activity results in delays in future works or decrease of crop efficiency. This article shows the results of a technological research, focused on mechatronic adequacy of a subsoiler implement addressed under a structured design procedure that assures technological adaptations by assuring the operation of a control instrumented system with response to overloading. [ABSTRACT FROM AUTHOR]

In the field experiment the influence of 7 species of cover crops: Secale cereale, Avena sativa, Vicia sativa, Sinapis alba, Phacelia tanacetifolia, Fagopyrum esculentum, Helianthus annuus and 4 kinds of pre-winter tillage on weed infestation of field after winter were investigated. The use of cover crops reduced the weed infestation of field as compared to cultivation without cover crop. White mustard, spring rye, and phacelia mulch reduced most strongly the weed amounts. The no-tillage system increased the weed infestation of field as compared to conventional cultivation (mouldboard ploughing). The weed control effect of pre-winter tillage using stubble cultivator did not considerably differ from conventional plough tillage. The largest number of weeds was recorded in no-cover crop cultivation in no-tillage variants and in those cultivated using subsoiler, while the smallest, when the oat, rye, or white mustard biomass was mixed using deep mouldboard ploughing before winter. In ploughless tillage system, the best effect of weed infestation reduction was obtained when white mustard biomass was mixed with the soil before winter, using stubble cultivator (grubber). [ABSTRACT FROM AUTHOR]

In the industrial activity occur in many cases technical incidents followed by crude oil contamination of adjacent areas, i.e. liquid petroleum products. Spreading liquid petroleum products to the soil surface may have negative effects on both the subsoil and groundwater by infiltration and the atmospheric air by evaporation of pollutant compounds with high volatility. Making remediation of a site contaminated with petroleum liquid and its sustainable ecological restoration and is one of the most complex environmental projects, both in the technical, economic and organizational. Choosing the optimal remediation technologies technically and economically is a difficult decision because a large number of involved parameters and a large number of interactions that influence the system and make it virtually impossible to control completely the final results. [ABSTRACT FROM AUTHOR]

Most sandy soils in coastal plains of the southeastern USA have a compacted zone or hardpan which limits root penetration below the plowing depth, reducing yields, and predisposing plants to drought stress. The hardpan layer exhibits a great amount of variability in depth and thickness in this region. Real-time, sensor-based, site-specific tillage could achieve significant savings in energy requirements for subsoiling and increase crop yields. Replicated tests were conducted to evaluate the performance of the Clemson instrumented subsoiler shank under actual field conditions. The instrumented subsoiler shank was calibrated against cone penetrometer readings on three coastal plain soil types. A strong positive correlation between soil strength values measured with the penetrometer and the instrumented subsoiler shank was observed ( R 2 = 0.89–0.97). On average, the shank index values (measured horizontally) were about 50% less than the corresponding cone index values (measured vertically). The effect of soil moisture content on shank-penetrometer correlation was not significant ( α = 0.05). It is possible to determine the depth and thickness of the hardpan layers with the instrumented subsoiler shank either for real time control of subsoiling location and depth or for generating site-specific tillage maps. [ABSTRACT FROM AUTHOR]

Rising fossil fuel prices are leading to an increasing awareness of energy efficiency in plant production. Tillage in particular can consume large amounts of fuel. For four tillage implements (reversible mouldboard plough, short disc harrow, universal-cultivator, subsoiler), this study quantifies the effect of different working depths on fuel consumption, wheel slip, field capacity and specific energy consumption. A four-wheel drive tractor (92 kW) was equipped with a data-acquisition system for engine speed, vehicle speed, wheel speed and fuel consumption. Fuel consumption was measured in the fuel system with an integrated high-precision flow-meter. The results show that the area-specific fuel consumption increased linearly with working depth for both the mouldboard plough and the short disc harrow, but disproportionately for the subsoiler. Wheel slip was found to increase fuel consumption and decrease field capacity performance at all depths. The influence of the engine speed was shown in a separate experiment with a universal-cultivator. Increasing the engine speed from 1,513 r min-1 to 2,042 r min-1 results in an increase of 80% for the fuel consumption rate (L/h) and 35% for the area-specific fuel consumption (L/ha). Future measurement of drawbar pull will allow a more detailed analysis of the energy efficiency losses at the engine, the transmission, and at the wheel/soil interface. [ABSTRACT FROM AUTHOR]

Since the design of the subsoiler is a complex work, the interaction between the subsoiler and soil was investigated by using Distinct Element Method (DEM) in this study. Based on the traditional discrete element theory, the 3D model of soil particles and the subsoiler were established after considering the liquid bridge force between soil particles. The operating resistance curves of the subsoiler were achieved after the DEM simulation at a speed of 1 m/s, and three depths of 180 mm, 220 mm and 260 mm, respectively. The simulation curves agreed well with the field experimental results based on relative errors of 2.96%, 14.95% and 7.15%, respectively, at three depths. All these data proved that it was feasible and favorable to analyze the performance of the subsoiler by using the DEM and it is of important significance for studying and further optimizing the structure of the subsoiler. [ABSTRACT FROM AUTHOR]

The objectives of this investigation were to investigate the effects of plowing depths (D) (35, 45, 55, and 65 cm), forward speeds (S) (0.341, 0.551 and 0.761 m sec-1) and outfitted subsoiler foot with wings on equipment performance for two subsoiler shanks arrangement (oblique and parallel) in silty clay loam soil. A significant (p<0.01) decrease in draft and specific resistance were observed for oblique shank arrangement compared with parallel shank arrangement. Furthermore, the draft and disturbed area increased significantly (p<0.01) with increasing operating depth, whereas specific resistance decreased significantly (p<0.01) with depth for the oblique and parallel shanks arrangement respectively. The values of draft, disturbed area and specific resistance of the oblique and parallel shanks arrangement tested were affected significantly (p<0.01) by adding wings to subsoiler feet. Forward speeds had a significant (p<0.01) effect on studded parameters. The optimal performance were found with the forward speed of 0.341 m sec-1. [ABSTRACT FROM AUTHOR]

The tillage and residue management during soil bed preparation need to be in appropriate manner for sustainable farming practice. The effects of tillage and residue management methods on corn cropping were studied on loamy soil in Bangrakum district, Phitsanulok Province, Thailand. The effects of five commonly used tillage methods: subsoiler tillage (ST), three methods of conventional tillage (CT1, CT2 and CT3), no-tillage (NT), as main factors and two corn residue management methods; burned (R1) and unburned (R2), as sub-factors were studied in a randomized strip plot configuration. Tillage treatment showed significant effect on physical and chemical soil properties, plant growth and development, grain yield, total aboveground biomass and most importantly the weed emergence and density, while the two crop residue management methods did not show significant differences. The improvement in plant development and grain production was found to be due to the increased tilled depth and thus the ST was the most effective tillage method for improving soil physical properties and to increase corn production; corn growth, biomass and grain yield. ST showed higher total grain yield than CT1, CT2, CT3 and NT approximately 35%, 101%, 88%, 216%, respectively. It could be concluded that ST as the best and sustainable method of soil management for corn cropping while having typical weeding and fertilization practices [ABSTRACT FROM AUTHOR]

Abstract: Compacted soil hardpans restrict crop growth by limiting root access to moisture and nutrients in the subsoil. Mechanically disrupting this hardpan profile is necessary in many soils to promote proper root elongation and crop growth. Subsoiling is the primary deep soil tillage practice which needs to be done once every two to three years depending on soil type and conditions. To maintain an adequate amount of residue for conservation systems, subsoiling should be performed without excessively disturbing the soil surface. However, most subsoilers disrupt the soil surface excessively and cover valuable crop residues. The objective of this study was, therefore, to design an alternative subsoiler for conservation tillage systems that minimized soil disturbance and energy requirements while adequately disrupting compacted soil profiles. Ground-driven rotary subsoilers were designed and manufactured by dividing a 1.2m diameter coulter into multiple blades. Minimizing the sliding soil resistance on the side of the coulter was one of the main considerations in forming the shape and number of blades. An experiment was conducted in the soil bins of the USDA-ARS National Soil Dynamics Laboratory in Auburn, AL, USA to determine the effects of ground-driven rotary subsoilers on soil disturbance and energy requirements compared with a large coulter and a typical subsoiler. Treatments were four different types of subsoilers (coulter-no-blade, coulter-5-blade normal direction, coulter-5-blade reverse direction, and shank-type) and two tillage depths (25 and 38cm). Soil disturbance, cone index, bulk density and draft were measured and statistical analyses conducted to determine the differences between subsoilers. The coulter-5-blade normal direction and coulter-5-blade reverse direction subsoilers required considerably less draft power (from 10 to 68%) for both operation depths than coulter-no-blade and shank type subsoilers. Coulter subsoilers minimized soil disturbance and required higher draft energy (from 22.5 to 33.5%) per volume of disturbed soil than the shank-type subsoiler. The soil disruption paths of coulter-5-blade subsoilers have an advantage for row crops due to limited above-ground disturbance if seeds can be placed in the middle of the disrupted zone. [Copyright &y& Elsevier]

A subsoiler of single tine was designed and provided with two shallow tines fixed in front of it. The shallow tines lateral distance between them can be changed. The leg of the subsoiler was provided with foot and the foot was provided with wings at one stage of the experiments. The subsoiler was tested in silty clay soil using four operating depths 30, 40, 50 and 60cm. Three lateral distances were used between the shallow tines 40, 50, and 60 cm. Wings were also used at one stage of the experiments. The subsoiler combinations are S, S+sh40, S+sh50 and S+sh60. The draft force of the subsoiler combinations increased as the operating depth increased. The increase was between 15.82 to 17.88kN for four subsoiler combinations when the operating depth increased from 30 to 60cm. The draft force requirement of each centimeter of depth on average is 0.560kN. Using shallow tines with subsoiler increased the draft force requirement and it increased with lateral distance between the shallow tines. The draft force requirement with shallow tines increased as the operating depth increased. The draft force requirement of each centimeter of shallow tines lateral distance for the shallow tines (30cm) is 0.062kN it increased to 0.091kN (91N=9.3kg). Providing the subsoiler with wings increased its draft requirement especially at greater depths. The highest draft requirement was recorded to deeper operating depth (60cm), wider lateral distance (60cm) and with wings on the foot of the subsoiler. [ABSTRACT FROM AUTHOR]

Rototiller-Subsoiler for the quick preparation of soil is an implement cocktail, designed for minimum tillage and the troughed inside the greenhouses, such as the descompaction, subsoil tillage and weed control. This consists of: wing, subsoiler organ, and transmission box and blades. It is based in the operation of a motor backdigger that we usually call rototiller. It is a series of blades that rotate on a horizontal axis, these penetrate in the soil and they pulverize it, at the same time the subsoiler that is added carries out the descompaction work, leaving it ready for the planting, taking advantage of the residual humidity of the land. As a result of the carried out work a team is able to carry out the preparation of soil inside the greenhouses: fluffed and subsoilation, works that are carried out in a single pass. [ABSTRACT FROM AUTHOR]