Ploughing Operations Research Articles

Variation of Surface Soil Quality Parameters by Intensive Donkey-Drawn Tillage on Steep Slope

Few direct measurements are made to quantify the erosion from upslope to lower field boundaries by intensive tillage. We conducted 50 plowing operations over a 5-d period using a donkey-drawn moldboard-plow on steep backslope in the Chinese Loess Plateau. Topographic changes at different slope positions were quantified using differential global positioning system (DGPS). Soil organic matter (SOM), extractable P and N, and soil bulk density were measured along a downslope transect after each 10-tillage series. Fifty operations resulted in a decrease in maximum soil surface level (SSL) of 1.25 m in the upper slope position and an increase of 1.33 m at the bottom of the slope. Slope gradients decreased from 37 to 14° at the upper position and from 18 to 0° at the lower position. Surface soil bulk density increased from 1.14 to 1.28 Mg m−3 in the upper slope and decreased from 1.10 to 1.03 Mg m−3 in the middle slope. Mean SOM concentrations in the upper and middle positions of the slope decreased from 8.3 to 3.6 g kg−1, mineral N from 43.4 to 17.4 mg kg−1, and Olsen-P from 4.5 to 1.0 mg kg−1 Intensive tillage resulted in a short-term increase in SOM and available nutrients in the lower portion during the tillage operations. Geomorphologic evolution and landscape variability of dissected hillslopes are attributable to soil movement and resulting physical and fertility degradation induced by intensive tillage.

Carbon sequestration in a long-term conventional versus conservation tillage experiment

The impact of conservation tillage practices on carbon sequestration has been of great interest in recent years. Changes in the soil organic carbon (SOC) as influenced by tillage, is more noticeable under long-term rather than short-term tillage practices. This experiment analyzed the organic carbon status of soils sampled at depth increments from 0 to 60 cm after 25 years of five tillage treatments in a silt loam soil. Zero tillage (ZT) treatment was compared to conventional tillage practices of mouldboard and chisel plow operations conducted either during the fall or spring season in a randomized complete block design with four replications. The SOC was calculated on depth and equivalent soil mass bases. Contrast analysis showed a significantly (5%) higher soil bulk density for zero versus fall and zero versus chisel tillage operations at 5–10 cm soil depth. The SOC concentration was dependent on the depth of tillage operation and followed the trend of higher SOC for zero, chisel, and mouldboard tillage at 0–5, 5–10, and 20–40 cm depth, respectively. There were more significant differences in the SOC storage when expressed on depth compared to an equivalent soil mass basis. SOC storage was significantly higher for ZT at the 0–5 cm soil depth compared to conventional tillage practices. Contrast analysis on an equivalent mass basis showed that SOC storage was significantly higher for spring tillage compared to fall tillage at 0–60 cm depth. In conclusion, ZT practices increased SOC concentration and storage compared to conventional tillage operations only for the surface layer but not for the entire soil profile.

Studies on ergonomic problems in agricultural machinery operations

To identify the ergonomic problems encountered by the users during operation of various agricultural implements and machinery, a case study was undertaken in Trichy, Pudukkottai and Tiruvannamalai districts of Tamil Nadu by interviewing farmers using prestructured questionnaire. The ergonomical problems faced by the farmers were listed and analysed using Statistical Package of Social Science (SPPS), in terms of postural discomfort jerks/vibrations, pain on body parts, force required and drudgery involved. About 59 per cent of jerks/vibration occurred during initial ploughing operation. Hand tools required "too much" force in operation of animal drawn implements. About 86 per cent of farmers experienced drudgery in operating animal drawn implements whereas only. About 28 per cent of farmers felt drudgery with power operated equipment. Eye/skin irritation was experienced by 65 per cent of workers during pesticide application due to non-use of protective clothing, hand gloves, goggles etc.

Tillage Influence on Soluble Salt Movement in Silt Loam Soils Cropped to Paddy Rice

Rice (Oryza sativa L.) produced in a dry‐seeded, delayed‐flood system common to the southern USA is extremely sensitive to excessive accumulation of soluble salts during the seedling growth stage. Recent observations have been made by producers, county agents, and researchers that the use of conservation tillage systems, particularly no‐till systems, may increase the level of salinity in the rice root zone in dry‐seeded, delayed‐flood systems during the 4‐ to 6‐wk period prior to permanent flood establishment. With the use of conservation tillage practices for rice production steadily increasing in the southern USA, it is important to determine if these practices increase potential for accumulation of soluble salts, to determine the mechanisms involved, and to develop management strategies to overcome the problem. A 2‐yr study was initiated in the fall of 1994 to monitor salt distribution within the soil profile under different tillage regimes. A conventional system, a para‐till operation, a chisel plow operation, and a no‐till system were implemented in the fall and Br− was applied to monitor salt movement. ‘Kaybonnet’ rice was seeded during 1995 and 1996 and soil samples were collected from each plot at the two‐ to three‐leaf growth stage. Salt accumulation at the rice seedling growth stage near the soil surface was higher in the no‐till treatment than in any of the other tillage treatments based on higher electrical conductivity, Cl− concentration, and NO−3 concentration in the top 2.5‐cm depth. At this depth, the electrical conductivity was 30 to 40% greater, the Cl− concentration was 30 to 160% greater, and the NO−3 concentration was 10 to 160% greater in the no‐till treatment than in the other tillage treatments. Salt distribution within the profile was similar for all treatments beyond the 2.5‐cm depth. The data suggest that tillage does tend to reduce the potential for salt accumulation in the root zone.

Defining the Operator Interface of a Snowplow Lane Tracking System from Field Interviews and Surveys

Maintaining lane position during low-visibility conditions can be a challenge for snowplow operators. Providing continuous and accurate lane position information to complement existing roadway cues may be the solution to increasing driver awareness. The first phase of a systemsbased approach to designing the operator interface for a snowplow lane tracking system is described. Through a systems-based approach, not only can the type of controls and displays to use for the operator interface be better defined, but the interface’s role and the amount, type, and presentation of information can be determined. In this first phase, ridealong interviews and an operator survey were used to identify factors affecting forward visibility and lane position in snowplow operations. More than 1,000 department of transportation snowplow operators from Iowa and Minnesota completed the survey. Ride-along drives showed that operators frequently lose sight of the forward roadway for brief periods and use several cues to adjust the lane position of their vehicles. Survey findings indicated that center and shoulder lines are helpful and intuitive cues for left- and right-wing plow operations. Additional findings suggest that operators need a flexible system that enables them to adjust alarm thresholds and that the operator interface should be designed as an aid rather than as a primary display. Because drivers do not have the visual resources for a dedicated display, a peripheral visual or haptic (tactile) display could be used to complement existing roadway cues.

Assessment of tillage erosion rates on steepland Oxisols in the humid tropics using granite rocks

Soil translocation by tillage may be an important factor in land degradation in the humid tropics. The objective of this study was to evaluate tillage-induced soil translocation on an Oxisol with 25% and 36% slopes in Claveria, Philippines for three tillage systems: contour moldboard plowing (CMP), moldboard plowing up and downslope (UMP), and contour ridge tillage (CRT). Small rocks 3–4 cm in “diameter” were used as soil movement detection units (SMDU). The SMDUs were placed at 10 cm intervals in a narrow 5-cm-deep trench near the upper boundary of each plot, the position of each rock recorded, and the trench backfilled. Five tillage operations used to produce one corn crop were performed during a one month period: two moldboard plowing operations for land preparation (except for CRT), one moldboard plowing for corn planting, and two inter-culture (inter-row cultivation) operations. After these operations, over 95% of the SMDU were recovered manually and their exact locations recorded. Mean annual soil flux for the 25% slope was 365 and 306 kg m −1 y −1 for UMP and CMP, respectively. For the 36% slope, comparable values were 481 and 478 kg m −1 y −1. Estimated tillage erosion rates for the 25% slope were 456 and 382 Mg ha −1 y −1 for UMP and CMP, respectively, and increased to 601 and 598 Mg ha −1 y −1, respectively, for the 36% slope. The mean displacement distance, mean annual soil flux, and mean annual tillage-induced soil loss for both slopes were reduced by approximately 70% using CRT compared to CMP and UMP.

Population dynamics and dispersal of Lepthyphantes tenuis in an ephemeral habitat

AbstractThe population dynamics of Lepthyphantes tenuis (Blackwall) were investigated in two fields of winter wheat in Sussex, England, with the aim of attributing the major factors controlling population fluctuations. Continuous measures of changes in density, reproductive rate and dispersal were obtained using a range of methodologies, including laboratory analysis, suction trapping, rotary sampling of the aerial fauna, caging, and detailed density estimations. The resulting data were then used to determine the major causes of the observed population fluctuations and to describe the processes of dispersal and reproduction in this population.Population densities were initially very low following ploughing operations, but increased throughout the season as a result of high reproductive rates. Investigation of the reproductive potential of the spiders showed that the number of eggs per egg‐sac did not vary with season, and that egg development was temperature related. There was no evidence that the number of viable eggs per egg‐sac varied during the season. There were three peaks of hatchling production per year suggesting two to three generations of spiders. Dispersal was not responsible for the major changes in field density throughout the season although dispersal activity was high for this species. Dispersal activity increased with age and was highest in females. Dispersal activity as a ratio of activity/field density for females, males, sub‐adults, immatures and hatchlings was 4:2:3:1:1.Aerial dispersal is only possible under suitable weather conditions. It was found that female dispersal was correlated with weather conditions far more strongly than other population groups. Calculations showed that under suitable weather conditions (e.g., 25% of the time being suitable for dispersal), almost 4% of the adult females could be expected to leave the population daily. The overall effect is therefore to displace individuals from the population but to have little effect on densities. Dispersal in other stages was controlled by the suitability of weather conditions but also by other, undetermined factors. It is postulated that L. tenuis has a life history strategy whereby suitable habitats act as sources of spiders, mainly females, which are continually involved in dispersal. Dispersal in other population groups may be triggered by factors such as the avoidance of adverse conditions. This type of life‐history strategy is typical of organisms, such as weeds, that are successful in ephemeral habitats and may indicate that this species originally evolved in unpredictable habitats such as dry river beds or coastal areas.

Forward-Lighting Configurations for Snowplows

Snow and ice control is a critical maintenance operation for New York State: each winter, up to 68 500 km (42,500 lane-mi) of highways must be cleared. Visibility during plowing operations is often poor and is further diminished by backscatter glare from the snowplow's own headlights as well as glare from lights of oncoming traffic. Results are summarized of a pilot study to identify forward (front-end) lighting configurations that might improve visibility for plow operators during such operations. During the 1993-1994 winter, eight lighting configurations were tested, two of which were identified as potential improvements over the existing pattern. Simple procedures and forms were developed for collecting reliable data. Methodological issues in performing such experiments are discussed. A statistical methodology is presented that is suitable for comparison of lighting configurations but is also applicable in other, broader contexts in which a number of items are compared by several evaluators.

Forward-Lighting Configurations for Snowplows

Snow and ice control is a critical maintenance operation for New York State: each winter, up to 68 500 km (42,500 lane-mi) of highways must be cleared. Visibility during plowing operations is often poor and is further diminished by backscatter glare from the snowplow's own headlights as well as glare from lights of oncoming traffic. Results are summarized of a pilot study to identify forward (front-end) lighting configurations that might improve visibility for plow operators during such operations. During the 1993–1994 winter, eight lighting configurations were tested, two of which were identified as potential improvements over the existing pattern. Simple procedures and forms were developed for collecting reliable data. Methodological issues in performing such experiments are discussed. A statistical methodology is presented that is suitable for comparison of lighting configurations but is also applicable in other, broader contexts in which a number of items are compared by several evaluators.

The application of high resolution fluxgate gradiometery as an aid to excavation planning and strategy formulation

The excavation of the Late Roman and Anglian settlement at West Heslerton, North Yorkshire, has been one of the largest excavations undertaken in England in the last twenty years. It has been the setting for a number of developments and experiments in the application of 'the new technology' to field archaeology. Parts of the site, which extended over c.20 Ha., proved to have high magnetic susceptibility and were ideally suited for magnetic prospection techniques. Feature visibility contrasts were, however, frequently low and therefore a series of experiments were undertaken using high resolution fluxgate gradiometer surveys following removal of the topsoil. The results of the high resolution surveys undertaken on the cleaned excavation surface proved highly successful in providing an enhanced pre-excavation plan, adding considerable detail to the surveys undertaken prior to the start of the excavation. The careful examination of the results, using G-Sys geographic data management software, which enabled the magnetic data, finds plots and digitised plans to be fully integrated, indicated areas where stratigraphic relationships could be tested and assisted in the development and re-definition of the excavation strategy as it progressed. Following initial small area tests in 1991, nearly two hectares were documented in this way during 1995 facilitating the completion of a targeted sampling operation which ensured the completion of the excavation within the limited budget available. The approach proved highly successful and offers great potential for use on sites which have a high magnetic susceptibility and are liable to large area destruction as occurs in the case of mineral extraction or subsoil ploughing operations.

Physical workload during selected farm operations.

An investigation was conducted to determine the physical workload on agricultural workers during selected farm operations in paddy fields in Thailand. Four male and four female agricultural workers were randomly selected. Four common farm operations, i.e. ploughing, planting, weeding and harvesting, were selected. The physical responses in terms of heart rate, oxygen consumption and pulmonary ventilation were determined as a function of physical work capacity on a laboratory bicycle ergometer. During different field operations, heart rate, oxygen consumption and pulmonary ventilation were recorded and energy expenditure, oxygen pulse and relative cost were estimated. The postural discomfort was also assessed during different farm operations. It was observed that the physical workload for ploughing, planting, wedding and harvesting operations, expressed in percent of physical work capacity, was 44, 41, 33 and 44%, respectively. Ploughing was found to be the heaviest work and other operations were moderate. Postural discomfort was higher for ploughing than for other operations.

Ride Simulation of Passive, Active, and Semi-Active Seat Suspensions for Off-Road Vehicles

ABSTRACT MATHEMATICAL models were developed for passive, active, and semi-active seat suspension systems. Each suspension model was combined with a three degree of freedom model of the vehicle operator to formulate models of the ride systems of off-road vehicles. Ride performance of the suspensions were computer simulated using the ride models at the various natural frequencies and damping ratios of the suspension systems. The input vibrations for the simulation were obtained by measuring a real time history of accelerations at the base of the seat suspension of agricultural tractors during transport and moldboard plowing operations. The output of the simulation was presented in terms of the ISO frequency weighted root mean square accelerations of the operator's head, body, and pelvis at the preferred one third octave frequency bands. The acceleration levels were evaluated in the criteria of the ISO 8 h fatigue-decreased proficiency boundary. Absorbed power of the operator was also computed for assessing relative ride performance of the suspension systems.

Technological Success, Urban Growth, and Rural Depopulation: The Mallee of South Australia

Bill Bauer's property, some 30 kilometers north of the nearest town (Pinnaroo, population 850) in South Australia, is 1200 hectares of broad, loamy plains separated by east-west linear sandy rises (which may be up to half a kilometer wide and up to 20 meters high) on average about 2 kilometers apart. The property includes a block of 240 hectares, some 15 kilometers distant, which he bought three years ago to provide additional grazing for his 500 sheep, to maximize his investment in expensive farm machinery, and to enable him to crop a larger area as part of the rotation system of one crop every 3 or 4 years from each field. His decision to purchase was also encouraged by the need at some time in the future to divide his own property between his two sons and to provide each with a reasonable area. Bill manages the property with only the help of his wife and two teenage sons in their school holidays. He has over $100,000 invested in sophisticated farm machinery: his power supply, two tractors (one tracked for heavy ploughing operations), wide harrows, disc-ploughs, seed-drills, and a self-driven combineharvester able to harvest a swathe over 4 meters wide. With these he can produce the wheat crop, which pays the basic household bills, but for the annual shearing of the sheep flock he must hire a team of two professional shearers for 2-3 days. The wool, together with the occasional sale of culled sheep, provide Bill's profits. Bill has been on the property since birth-over 50 years ago. His own brick wall, corrugated-iron-roof house stands beside his father's original house of local kunkar limestone, now badly crumbling and used as a machine shed and equipment store. His father rolled down the Mallee, the original vegetation of many-branched eucalypt shrubs up to 10 meters high which gave its name to the region, with horse teams pulling clumsy but effective rollers of logs on old steam boilers at the time of the First World War. He survived the World Depression of the 1930s by selling off the Mallee roots as fuel for suburban homes in the state capital of Adelaide when the returns from the wheat crashed, and he taught Bill by his own example how to cope with the periodic droughts which ravaged the countryside. As a boy, Bill could recall about 40 families living within a 10 kilometer radius of the property; now there are only 25 families left-the abandoned houses left derelict or used as storage sheds; the land still farmed but in units two to four times the original size. As a boy, Bill could also recall the great dust storms of the 1930s and 1940s when, as the result of official encouragement to conserve soil moisture, large areas were left fallow through the year and, in drought, high winds caused massive soil erosion. In 1944 dust from the Mallee area fell on the New Zealand snowfields, some 3500 kilometers away. There is still plenty of dust during droughts in the

The use of baits treated with α‐chloralose to catch wood‐pigeons

SUMMARYWood‐pigeons were induced to take wheat, barley, oats, peas and beans when these were spread on fields where the birds were feeding. When these foods were scattered on pastures in winter (January‐March) they were taken in preference to the pigeons' normal food of clover. These results are discussed in relation to food preferences and the role of a ‘search image’ in the feeding behaviour of the species.Cereal and pea baits containing 1·5% by weight of α‐chloralose were laid on a variety of feeding grounds used by wood‐pigeons during the periods 27 October 1959 to 21 March 1960 and 4 November 1960 to 18 June 1961. In a total of thirty‐four such trials 1408 birds were narcotized. Of these 57% were wood‐pigeons and 20% were legally protected or game species. Using cereal baits the risk to species other than wood‐pigeons was lowest on pasture, where 74% of the birds caught were wood‐pigeons, 5% were game species and less than 1% were protected birds.Of the narcotized wood‐pigeons, 81% recovered unharmed, and partridges and pheasants had similar recovery rates. Only 38% of the stock‐doves recovered and the small finches (including house and tree sparrows) also had a low recovery rate of less than 50%. Baits normally disappeared within about I week. In a few cases they persisted for longer periods, the maximum being 31 days. Uneaten baits were lost through settlement in the soil, germination and ploughing operations. Birds were captured throughout the whole period during which bait was available.Three trials using peas treated with 1·5% by weight of a‐chloralose were conducted between 7 November 1961 to 22 January 1962. Thirty‐nine wood‐pigeons and thirty‐one game birds were narcotized and captured but no small protected birds were affected. The recovery rates of the captured birds were similar to those narcotized by using cereal baits. The method is much cheaper than control by shooting or nest destruction.The method of using stupefying baits is potentially a valuable means of wood‐pigeon control but further field tests are necessary. Only baits such as peas and beans are at present suitable as these appear to be too large to be eaten by the small protected species.

A New Method of Planting Sugarcane

In the south Madras, the monsoon is active from July to November with occasional showers upto mid January, the heaviest rain fall being in October and November months. In lighter sandy soils, preparatory operations like deep ploughing could be carried on with some difficulty by the end of January and February. In heavy soils, particularly in the eastern Tanjore delta, the soil is too wet and it is not ready for any ploughing operations till late in February or March. The delay is greater, particularly when the fields are surrounded by swamp paddy crop varieties like late 'samba', which come for harvest by February-March. Planting of sugarcane under such soil conditions is generally not possible till March or April.