Permanent Traffic Lanes Research Articles

Identification of wheel track in the wheat field

Agriculture machinery navigating along permanent traffic lanes in the farmland may avoid causing extensive soil compaction. However, the permanent traffic lanes are frequently covered up or eliminated by following tillage practices. It is necessary to identify the wheel tracks designed as permanent traffic lanes in order to ensure the agriculture machinery travels along the designated wheel tracks when cultivating the field. This study proposed an identification method of wheel tracks based on the morphological characteristics of wheel tracks and the environmental conditions around the wheel tracks in the wheat fields. The proposed method first utilized the maximum interclass variance to identify the contours of the main part of the wheel track and the shadow regions around the wheel track’s edges. The main part of the wheel tracks was then separated from interference pixels by moving the centerline of the main part of the wheel track, which was derived by skeleton algorithm and curve fitting, towards the right or left edge of the wheel track at a specific distance. In a morphological opening operation, specific linear and circular structural elements were used to segment the shadow regions along the edge of the wheel track. The remaining wheel track was finally recognized by computing the complement of the region identified. After achieving the segmentation of wheel tracks, many reference points near the outside of the wheel track edge in the original image were chosen as fiducial points for evaluating the differences between the actual value and the recognized wheel track edge. The evaluation was based on computing the root mean squared error (RMSE) and the mean absolute error (MAE) of coordinates of reference points and recognized wheel track edge. The results showed that the largest RMSE and MAE were 24.01 pixels (0.0045 m) and 17.32 pixels (0.0032 m), respectively. The low values of RMSE and MAE reveal that the accuracy of the algorithm developed in this study is high, and using this algorithm may segment the wheel track in the wheat field accurately.

Effects of Tractor and Soil Parameters on the Depth of the Permanent Traffic Lanes in Controlled Traffic Farming Systems

One of the basic requirements for controlled traffic farming (CTF) is the precise motion of all agricultural equipment on permanent traffic lanes (PTL). Tractors of machine-tractor units are then equipped with a GNSS (global navigation satellite) RTK (real-time kinematic) system, even though in many parts of the world, and Europe as well, satellite navigation is not yet used. In this case, for implementation of the CTF system, it needs to lay such PTL tracks that would be sufficiently visible, especially when using the CTF system in multi-year agricultural crop cultivation. The PTL track depth is influenced by both tractor and soil parameters and, in this paper, this influence is studied considering the dimensionless π-terms of the similarity theory. To obtain a greater depth of PTL tracks (h), the soil cone index must be low. The low density of the soil is important, even if its effect on the parameter h is less than that of the soil cone index. A greater depth of PTL tracks is also obtained by increasing the inflation pressure in the tractor tires. Ballasted wheels are the least effective for increasing the value of the parameter h.

Patch cropping- a new methodological approach to determine new field arrangements that increase the multifunctionality of agricultural landscapes

Agricultural intensification decreased land cover complexity by converting small complex arable field geometries into large and simple structures which then were managed uniformly. These changes have led to a variety of negative environmental effects and influence ecosystem services. We present a novel small-scale and site-specific cropping system which splits a large field into small homogeneous sub-fields called ‘patches’ grouped in different yield potentials. A detailed workflow is presented to generate new spatially arranged patches with special focus on preprocessing and filtering of multi-year yield data, the variation in patch sizes and the adaptation of maximum working width to use available conventional farm equipment and permanent traffic lanes. The reduction of variance by the used cluster algorithm depends on the within-field heterogeneity. The patch size, the number of growing seasons (GS) used for clustering and the parallel shift of the patch structure along the permanent traffic lane resulted in a change in relative variance. Independent cross validation showed an increased performance of the classification algorithm with increasing number of GS used for clustering. The applied cluster analysis resulted in robust field segregation according to different yield potential zones and provides an innovative method for a novel cropping system.

Investigation of the Influence of Permanent Traffic Lane Properties on Rolling of Bridge Agricultural Equipment Wheels

Abstract Movement of bridge agricultural equipment along the permanent traffic lanes is characterised by significant energy costs for overcoming the rolling resistance forces. Until now, the movement process of bridge agricultural equipment wheels along the compacted soil of permanent traffic lanes has been paid only a little attention. It has been established that the physical and mechanical properties of soil lanes significantly affect the energy consumption necessary for overcoming the rolling resistance of forces of bridge agricultural equipment wheels. Considering the range of possible changes in these properties, the coefficient of rolling resistance of equipment wheels varies from 0.06 to 0.1, which is 66%. In order to reduce the rolling resistance coefficient of equipment wheels when moving along the permanent traffic lanes, the surface needs to be undeformable. When moving along such a solid and dense supporting surface, the wheel rolling resistance is lowest.

Controlled traffic farming effects on productivity of grain sorghum, rainfall and fertiliser nitrogen use efficiency

Controlled traffic farming (CTF) is a mechanisation system in which all machinery has the same (or modular) working and track width so that field traffic can be confined to the least possible area of permanent traffic lanes. CTF enables productivity of non-compacted crop beds to be optimised for given energy, fertiliser and water (rainfall) inputs. This study investigated the agronomic response and economic return of grain sorghum grown in compacted and non-compacted soils to represent the conditions of non-CTF and CTF systems, respectively. Yield-to-nitrogen (N) responses were derived following application of urea, 3,4-dimethyl pyrazole phosphate-treated urea (DMPP), and urea ammonium nitrate (UAN, 32% N) at rates between 0 and 300 kg ha −1 N. Selected soil properties were measured to guide parametrisation of the Agricultural Production Systems Simulator (APSIM), which was used to assess long-term (55 years) effects of CTF and non-CTF soil conditions on crop productivity, rainfall use efficiency (RUE) and develop rainfall-runoff relationships. Grain yield and yield components (harvest Index, grain thousand-grain weight, number of grains) were significantly higher in CTF compared with non-CTF. On average, the most economic N rates, and corresponding grain yields, were 144 and 3428 kg ha −1 , and 100 and 1796 kg ha −1 for CTF and non-CTF, respectively. When N inputs were optimised, agronomic efficiency calculations showed 18% increase in CTF compared with non-CTF. Nitrogen use efficiency (NUE) was 1.75 times higher in CTF than in non-CTF. Rainfall-use efficiency was about 65% higher in CTF, which concurrently reduced the amount of runoff compared with non-CTF. Average rainfall season (330–450 mm in-crop) grain yield was 30% lower in non-CTF compared with CTF. For subtropical conditions of Australia, long-term APSIM simulations showed that increased productivity and inter-season yield stability can increase gross margin of grain sorghum by AUD74 ha −1 or greater depending on the adopted tillage system and in-crop rainfall. In non-CTF systems, improvements in NUE and RUE are constrained by soil compaction. Enhanced efficiency fertilisers, such as DMPP-treated urea, cannot compensate for other stresses caused by soil compaction and therefore cannot achieve the same NUE and RUE as the CTF system. Adoption of CTF delivers improved resource-use efficiency and profitability in rainfall-limited environments. Long-term (1960–2015) simulation of grain yield (A) and runoff (D) as a function of in-crop rainfall. Modelled data for grain sorghum-fallow cropping on a Red Ferrosol in Toowoomba (Queensland, Australia) in controlled (CTF) and non-controlled traffic farming (non-CTF) systems, respectively. Continuous lines show the best fit to predicted data. Dotted vertical lines show the 30th (left) and 70th (right) percentiles rainfall, respectively. • Controlled traffic farming (CTF) increased long-term grain yields by 30% in average-rainfall seasons. • Fertiliser nitrogen use efficiency (NUE) was 1.75 times higher in CTF compared with non-CTF. • Rainfall use efficiency (RUE) was 65% higher in CTF compared with non-CTF, which significantly reduced runoff. • Avoidance of (random) field traffic is a pre-requisite for jointly improving fertiliser NUE and RUE. • In non-CTF, improvements in NUE and RUE are constrained by compaction. • Enhanced efficiency fertilisers cannot compensate for other stresses caused by compaction.

Experimental study of the implement-and-tractor aggregate used for laying tracks of permanent traffic lanes inside controlled traffic farming systems

Traffic-induced soil compaction is a serious drawback of modern agriculture. However, controlled traffic farming (CTF) systems, which have been adopted worldwide, are useful strategies of lessening this problem. In CTF systems, the crop zone is clearly separated from the permanent traffic lanes (PTL), which are used exclusively for the movement of the machine-and-tractor aggregates. The CTF systems are implemented both with and without the use of the GPS systems. When navigation-aid is not used, the first positioning of the PTL tracks is an essential operation, in which the aggregate intended for this task must perform a sufficiently straight movement. This paper reports the assessments concerning the PTL tracks laid by an experimental aggregate, which consisted of a four-wheel drive tractor and a tillage implement operating in the “push” mode. This aggregate formed tracks with a sufficiently small dispersion (10.30 cm2) and a fairly low (not more than 0.09 Hz) frequency of their fluctuations in a horizontal plane. Furthermore, during the tests, a rather close positive correlation between the bearing angle φ of the tractor and the turning angle α of its driven wheels was registered and the maximum value of the related correlation function was 0.9. Moreover, the phase (time) shift between the disturbing torque and the response to it by the tractor operator did not exceed 0.75 s. The use of the proposed aggregate allowed laying tracks with a depth of 21.2 ± 0.3 cm and vibrations in a longitudinal vertical plane, whose dispersion was not more than 2 cm2 and was concentrated in a fairly narrow frequency range from 0 to 1.78 Hz.

Effect of fuel saving and crop energy output on controlled traffic system under small machinery in loess plateau of China

Energy saving was one of the main benefits of controlled traffic system. Research on energy conservation mechanism of controlled traffic system with small scale agricultural machinery was conducted in the Loess Plateau of China, to quantify the energy efficiency of controlled traffic system. Three treatments were included: zero tillage with controlled traffic (NTCN), shallow tillage with controlled traffic (STCN), and conventional tillage with random traffic (CK). Results showed that controlled traffic system can increase soil compaction in traffic lane and reduce soil compaction in crop zone. Thus, controlled traffic system can significantly reduce tine opener working resistance, STCN reduced by 20.9 % at 2 km/h velocity and 19.3 % at 1 km/h velocity, NTCN reduced by 10.1 % in both velocity, compared with random traffic treatment CK. Therefore, average fuel consumption at wheat planting reduced 29.3 % in NTCN, and 31.5 % in STCN, compared with CK. Due to the soil and water conservation, significantly yield increase more than 20 % was observed in controlled traffic treatments, even with 20 % of the field was occupied by permanent traffic lanes. Consequently, crop equivalent energy was relatively higher in controlled traffic system. It was illustrated that controlled traffic system with small machinery in Loess Plateau of China was fuel saving system with higher total energy output.

Impact of permanent traffic lanes on the soil physical and mechanical properties in mechanized sugarcane fields with the use of automatic steering

The randomized traffic during all crop cycles in the Brazilian sugarcane production system enhances soil compaction. The use of automatic steering in controlled traffic farming represents an alternative to minimize soil compaction in the sugarcane fields. Our research aimed to evaluate the changes in the soil physical and mechanical properties under permanent traffic lanes, after three years of sugarcane mechanized harvesting, with the use of automatic steering. The experiment was carried out in the municipality of Nova Europa, state of São Paulo, Brazil, in a sugarcane area, under the following treatments: sugarcane planted in a single-row spacing (1.5 m) with conventional traffic, sugarcane planted in a single-row spacing (1.5 m) with automatic steering, and sugarcane planted with double-combined row spacing (1.50 × 0.90 m) and with automatic steering). The bulk density, soil porosity, soil penetration resistance, aggregate stability, and tensile strength of aggregates, were assessed in the inter-row center and seedbed. Soil load-bearing capacity was also included in this study by modeling of preconsolidation pressure at 0–0.1 m and 0.2–0.3 m of depth. After three years of mechanized operations, with controlled traffic using automatic steering, in a sugarcane field, the soil compaction was higher on the inter-row center (i.e. higher bulk density, tensile strength, and preconsolidation pressure and, lower macroporosity) than on the seedbed. The load-bearing capacity allowed to detect the pronounced effect of the machines’ traffic management systems on the soil compaction. The use of automatic steering reduced the load-bearing capacity in the seedbed in relation to the inter-row center, indicating that such management system preserves the soil physical quality in the ratoon region. Moreover, the lowest soil compression index values observed in the inter-row center, using management systems with automatic steering, indicates a lower susceptibility to undergo additional soil compaction.

Controlled traffic farming effects on soil emissions of nitrous oxide and methane

Soil compaction affects soil aeration and gas diffusivity, and thus has a major impact on the release of greenhouse gases (GHGs) from fertilised soils. Controlled traffic farming (CTF) systems reduce the area of compacted soil by confining all field traffic to permanent traffic lanes, and a pilot trial at one long-term CTF site provided evidence of reduced soil emissions. We investigated the effect of CTF on soil emissions of nitrous oxide (N2O) and methane (CH4) using replicated manual chamber measurements in 3 traffic treatments; namely: non-trafficked CTF beds, permanent CTF lanes, and a single traffic pass on CTF beds to simulate the random traffic tracks of non-controlled traffic farming. Emissions of N2O and CH4 were monitored from these treatments in 15 crops over 3 years on 6 grain farms in Queensland, Victoria and Western Australia. This work has demonstrated that N2O emissions from trafficked soil were consistently and significantly greater (by an average factor of 2.2) than those from non-trafficked soil. At the same time, soil CH4 consumption was significantly increased in the CTF beds compared to random-trafficked or permanent traffic lanes, although overall CH4 fluxes were small. Permanent traffic lanes normally represent only 10%–15% of field area on controlled traffic farms, compared with ∼50% or more trafficked area on non-controlled traffic farms. Thus, the results indicate that adoption of controlled traffic could reduce total soil emissions by 30%–50%. This demonstrates that CTF will reduce soil emissions of N2O and CH4 from mechanised crop production, while providing other agronomic, environmental and economic benefits.

Field Evaluation of Controlled Traffic Farming in Central Europe Using Commercially Available Machinery

Abstract. The progressive increase in the size and weight of farm machinery causes concerns due to the increased risk of soil compaction that arises from non-organized vehicle traffic. Controlled traffic farming (CTF) offers an effective means to manage compaction by confining all load-bearing wheels to the least possible area of permanent traffic lanes. Although CTF is relatively well-established in Australia and in some countries in Northern Europe, its benefits and suitability for Central European conditions have not been demonstrated. A long-term experimental site was established in 2010 in Nitra, Slovakia, using a 6 m “OutTrac-CTF” system with shallow non-inversion tillage practices. The 16 ha experimental field of loam soil is representative of land used for arable cropping in Central Europe. Four traffic intensities (non-trafficked, one traffic event per year with a single pass, multiple passes with permanent traffic lanes, and random traffic) were evaluated using two traffic systems: controlled (CTF) and non-controlled traffic farming (referred to as random traffic farming or RTF). This article reports the findings derived from the first four years of the project and focuses on the effects of traffic systems on yields observed in cereal crops (winter wheat, spring barley, and maize) grown at the site in a rotation cycle. Significant differences (p < 0.1) in yield are reported due to the heterogeneity of the field and the seasonal effect of weather. The results of this investigation suggest that CTF systems have potential to increase production sustainably in arable farming systems in Central Europe. Well-designed CTF systems using commercially available machinery allow for reductions in the area affected by traffic of up to 50% compared with random, non-organized traffic systems. Results also show that in years when soil moisture was not limiting, the yield penalty from a single (annual) machine pass was relatively small (~5%). However, in dry years, compaction caused by multiple machinery passes may lead to yield losses of up to 33%. When considering the ratio of non-trafficked to trafficked area within the different CTF systems evaluated in this study, yield improvements of up to 0.5 t ha-1 for cereals are possible when converting from RTF to CTF. Given the assumptions made in the analyses, such yield increases translate into increased revenues of up to 117 USD ha-1 (1 Euro= 1.1 USD). For Central European farming systems, the main benefit of CTF appears to be improved efficiency and enhanced agronomic stability, especially in dry seasons, where the significant yield penalty from machinery passes is likely. Keywords: Crop performance, Economic return, Field efficiency, Soil compaction, Traffic systems, Yield penalty.

Profitability of controlled traffic in grass silage production – economic modelling and machinery systems

Controlled traffic farming (CTF) systems aim to reduce soil compaction by restricting machinery field traffic to permanent traffic lanes. Grass-clover silage production is generally associated with intensive field traffic, resulting in reduced silage clover content. If CTF can increase yield and clover content in grass-clover leys, this would reduce the need for grain and expensive protein concentrate in dairy cow feed rations. A mixed integer programming model was developed to evaluate the potential profitability of CTF in a dairy farm context. Existing field trial data were used to calculate the expected yield outcome of CTF, based on reductions in trafficked area. The results revealed that CTF increased profitability by up to €50/ha. Total machinery costs are likely to increase on converting to CTF, but variable machinery costs are likely to decrease.

Evaluation Of Soil Physical Properties In System With Permanent Traffic Lanes Practised In 10 Ha Field

Abstract The paper deals with basic soil physical properties as affected by wheel traffic. Agricultural land is, in varying degrees, exposed to the pressures exerted by running parts of tractors, harvesting machinery and transport equipment. Damaging the soil by compaction increases the energy efficiency, deteriorates the quality of tillage, may reduce crop yields and is associated with environmental risks that accompany water erosion. The selection of results from field trials demonstrates the positive effect of the reduction of level crossings on the results of physical and mechanical properties of the soil.

Controlled Traffic Farming – From Worldwide Research To Adoption In Europe And Its Future Prospects

Abstract Controlled traffic farming is a machinery management system that confines all field vehicles to the least possible area of permanent traffic lanes. It has developed in response to research evidence of widespread soil damage from compaction due to field traffic. The history of research on soil compaction is explored and found to be a relatively new phenomenon. Controlled traffic farming as a topic for research did not appear until the 1980s although its principles and benefits were well established before then. Research expanded over the next decades but changed subtly to more reviews on the topic as well as emphasis on environmental deliverables and some economics studies. Few if any researchers attempted to develop on-farm systems using existing machinery until the mid 1990s when a small and dedicated team in Australia encouraged farmers to experiment. This quickly led to rapid expansion across the continent to its present day c. 13% of the cropped area. Despite changes to extension services in northern Europe at around the turn of the century and a move to subsidiarity, this did not alter the model of controlled traffic adoption. This followed a similar pattern to that in Australia involving individuals rather than organizations.

Advances in Cotton Harvesting Technology: a Review and Implications for the John Deere Round Baler Cotton Picker

To address the progressive increase in farmed land and the decline in labor, cotton production in more developed agricultural systems has seen a movement towards larger, heavier machinery with increased capacity. Recent innovation of on-board module building technology for cotton harvesters follows this trend, which has caused concern for the potential impact of the machine on the farming system. This review acknowledges past and present developments within the cotton harvesting system from both the machine- and soil-management perspectives to inform land managers, machinery manufacturers, technical advisors, and the scientific community of the incidence of soil compaction associated with technology uptake in cotton-based systems. Emphasis is made on the need to ensure that the effects of traffic-induced soil compaction are minimized. For this, the feasibility of confining compaction to the least possible area of permanent traffic lanes is examined along with engineering design constraints of commercially available cotton pickers. Fundamental information is elicited, which provided insights as to why this movement has occurred and how associated problems might be addressed. Within the Australia context, these cotton harvesters have undergone rapid adoption. This review uses this case-study to elucidate direct and latent impacts of the machine to help identify risks and develop management strategies as further technology is developed and adopted. Knowledge gaps that merit a research priority within soil compaction work for cotton-based systems are presented and a synthesis of how to proceed conceptualized.

The Potential of Controlled Traffic Farming to Mitigate Greenhouse Gas Emissions and Enhance Carbon Sequestration in Arable Land: A Critical Review

The drive toward adoption of conservation agriculture to reduce costs and increase production sustainably causes concern due to the potentially negative effects of increased soil compaction. Soil compaction reduces aeration, water infiltration, and saturated hydraulic conductivity and increases the risk of waterlogging. Controlled traffic farming (CTF) is a system in which: (1) all machinery has the same or modular working and track width so that field traffic can be confined to the least possible area of permanent traffic lanes, (2) all machinery is capable of precise guidance along those permanent traffic lanes, and (3) the layout of the permanent traffic lanes is designed to optimize surface drainage and logistics. Without CTF, varying equipment operating and track widths translate into random traffic patterns, which can cover up to 85% of the cultivated field area each time a crop is produced. Nitrous oxide (N2O) is the greatest contributor to agriculture's greenhouse gas (GHG) emissions from cropping, and research suggests that its production increases significantly under conditions of high (>60%) water-filled porosity when nitrate (mainly from fertilizer N) and carbon (usually from crop residues) are available. Self-amelioration of soils affected by compaction occurs slowly from the surface downward; however, the rate of amelioration decreases with increase in depth. Consequently, all soils in non-CTF systems in mechanized agriculture are prone to some degree of compaction, which compromises water infiltration, increases the frequency and duration of waterlogged conditions, reduces gaseous exchange between soil and the atmosphere, inhibits root penetration and exploitation of nutrients and water in the subsoil, and enhances N2O emissions. Adoption of CTF increases soil porosity in the range of 5% to 70%, water infiltration by a factor of 4, and saturated hydraulic conductivity by a factor of 2. The greater cropping opportunity and enhanced crop growth for given fertilizer and rainfall inputs offered by CTF, coupled with no-tillage, provide potential for enhanced soil carbon sequestration. Reduced need and intensity of tillage, where compaction is avoided, also helps protect soil organic matter in stable aggregates, which may otherwise be exposed and oxidized. There is both circumstantial and direct evidence to suggest that improved soil structural conditions and aeration offered by CTF can reduce N2O emissions by 20% to 50% compared with non-CTF. It is not compaction per se that increases the risk of N2O emissions but rather the increased risk of waterlogging and increase in water-filled pore space. There may be an elevated risk of GHG emissions from the relatively small area of permanent traffic lanes (typically <20% of total cultivated area) if these are not managed appropriately. Quantification of the benefits of compaction avoidance in terms of GHG emissions may be possible through the use of well-developed models.

Effect of controlled traffic system on machine fuel saving in annual two crops region in North China Plain

Energy saving was one of the main benefits of controlled traffic system. Research on the energy conservation mechanism of controlled traffic system with medium and small scale agricultural machinery was conducted in the North China Plain, to quantify the energy benefits of controlled traffic system. Two treatments were included: zero tillage with controlled traffic (NTCN) and zero tillage with random traffic (NT). Results showed that controlled traffic system can increase soil compaction in traffic lane and reduce soil compaction in crop zone. Controlled traffic system can reduced machinery field working force significantly through lower tire rolling resistance from relatively harder permanent track, and lower tine opener working resistance from softer soil in crop zone. Compared with NT, NTCN reduced traction force by 14.6%, 13.3% and 13.3% at subsoiling, wheat and maize no-till planting. Consequently, fuel consumption was reduced in all machine operation in controlled traffic system. Compared with NT, two years total fuel consumption in NTCN was significantly reduced by 19.79L/ha (23.7%). Besides, controlled traffic increased total annual yield and WUE by compensating yield loss in winter wheat through the yield benefit in summer maize, even though 30% of the field was occupied by the permanent traffic lanes. Although these results were preliminary, it was indicated that controlled traffic system was fuel saving system in small and medium machinery condition in North China Plain.

Effect of Wheel Traffic on Crop Performance in North China Plain

Controlled traffic system was an effective solution to soil compaction, thus to promote sustainable development. The objective was to evaluate the effect of small and medium machinery wheel traffic on soil conservation and crop performance in annual two-crop region in North China Plain. Three treatments were included, zero tillage with Controlled Traffic (NTCN), zero tillage with random Traffic (NT) and traditional tillage treatment with random traffic (CK). Based on the two-year controlled traffic experiment in North China Plain, it was illustrated that controlled traffic system NTCN reduced soil bulk density in 0-30 cm soil layer in crop zone by applying permanent wheel track. Due to the avoiding of compaction, crop performance was enhanced. Both winter wheat and summer maize yield components value were increased in NTCN, compared with NT and CK. Even 30% of the field was occupied by the permanent traffic lanes, controlled traffic still increased total annual yield and WUE by compensating yield loss in winter wheat from the yield benefit in summer maize. It was indicated that controlled traffic system improved soil structure, promoted crop performance and induced higher annual crop yield in the annual two crops region in North China Plain. Although these results are preliminary, it was indicated that controlled traffic system was a valuable farming system in small and medium machinery condition in North China Plain.

Long-term effects of different tillage and field operation regimes on soil structure

Only little is known about the rate and extent of structural evolution under the combined influence of tillage and wheeling. Whereas some quantitative information on the regeneration of compacted soils is available, the course and potential of structure formation and recovery under the absence of wheel traffic – as made possible by Controlled Traffic Farming (CTF) systems using permanent traffic lanes – are not well investigated and understood. Therefore the effects of tillage practices and field traffic organization on soil structure were studied in a crop sequence under practical soil management conditions on a loamy orthic luvisol at Tänikon, Switzerland (1187 mm mean annual precipitation, 8.0 °C mean annual temperature). From 2000 to 2008 the effect of no-till on soil structure evolution was studied on a formerly ploughed field and compared to continuously ploughed plots. Since 2008 the previous random field traffic organization was maintained in the ploughed and no-till plots, but changed to controlled traffic in plots formerly under shallow tillage and consecutively managed by no-till. Soil structure evolution was described by repeated samplings of undisturbed soil cores in the top- (10-15 cm) and subsoil (35-40 cm) and subsequent analysis of porosity, permeability and strength characteristics in the lab. In situ measurements of parameters characterizing soil water regime (volumetric water content, matric potential) and the soil environment (O2- and CO2-concentrations in soil air, oxygen diffusion rate, redox potential) under field conditions were done quasi continuously at several soil depths. Results show a slow evolution of structural properties in the subsoil and a limited structure formation in the absence of tillage measures in the topsoil. Soil structure evolution can be followed up in short-term cycles covering individual vegetation periods as well as in medium-term cycles covering crop rotation periods. In situ measurements of water retention characteristics and properties of soil environment revealed consistent but minor effects of field traffic organisation on processes depending on soil structure as well as on weather conditions.

Tillage, traffic and sustainability—A challenge for ISTRO

Tillage might be unnecessary for crop production, but no practical mechanised system can avoid field traffic, usually by wheels. Wheels can cause soil damage, but this can be limited to a small proportion of field area by restricting all heavy wheels to permanent traffic lanes. Widespread adoption of controlled traffic in Australia, and permanent raised beds in Mexico has demonstrated the effectiveness and practicability of Controlled Traffic Farming (CTF) systems in very different cropping environments. This paper considers the system impact of wheel traffic on productivity and sustainability of mechanised cropping, citing comparisons between CTF and conventional “random traffic” cropping systems where possible. Evidence of the extent and effects of wheeling on soil structure is summarised in terms of hydrology and crop performance. Soil erosion and broader environmental effects are considered briefly. Tillage and traffic effects on greenhouse gas emissions from cropping are discussed, including emissions from fuel, herbicide and fertiliser inputs. Soil emissions are considered in some detail, citing evidence from soil compaction studies, and where emissions have been monitored from wheeled and non-wheeled soil. Outcomes have been encapsulated in a spreadsheet comparison of emissions from cropping systems using tillage with random traffic, no-till with random traffic and CTF no-till. Using data from extensive grain production systems in Australia this indicates that CTF could provide a major reduction in cropping emissions. CTF can improve productivity, and all measures of sustainability; it also overcomes some important constraints to the adoption of conservation agriculture. As precise guidance becomes progressively cheaper, machine system width compatibility remains the only major impediment to a significant improvement in food security and the environmental footprint of cropping. Width compatibility is simple in principle, but complex in practice, and will occur only with the active engagement of the farm machinery industry. The paper urges ISTRO to join with regional farmer CTF groups to draw attention to this issue and provide a forum for the development of compatibility standards.

Modelling of material handling operations using controlled traffic

Controlled-traffic farming (CTF) is a management system that can eliminate soil compaction by wheels within the cropped area. According to the principles of CTF, permanent parallel wheel tracks are created within the field area. The benefits of CTF, in terms of productivity and sustainability, have been the subject of intensive research for a number of decades. This has led to the establishment of CTF in various regions around the world. CTF also has drawbacks that include the need to purchase specialised machinery, the loss of cropped area due to dedicated wheel tracks and the cost of creating and maintaining permanent traffic lanes within the fields. Furthermore, field efficiency is affected by CTF due to significant increases in idle time of in-field transport and the way the fields are traversed in material handling operations. During fertilisation, when tramline length and the driving distance needed to apply one tanker load of fertiliser are not coordinated, CTF does not allow for random turns and requires the tanker to drive empty along the traffic path. The inherent characteristics of the CTF system, as well as the fact that cooperatively owned machines are used to carry out the operations, makes existing models inadequate for evaluating field efficiency. In this paper, the development of a discrete-event model for the prediction of travelled distances of a machine operating in material handling operations using the concept of CTF is presented. The model is based on the mathematical formulation of the discrete events regarding the motion of the machine when performing the fieldwork pattern. To evaluate the model two slurry application experiments were designed. The experiments involved registering the position and monitoring the application status of the slurry applicator. Validation showed that the model could adequately predict the motion pattern of machinery operating in CTF. Prediction errors of total distance travelled, were 0.24% and 1.41% for the 2 experimental setups. The current model structure captures the interrelationships between the mutual influencing parameters of motion sequence and configurations of the CTF layout. This model has the potential to be used for autonomous vehicles.