Initial rollover effectiveness evaluation of an alternative seat belt design for agricultural tractors

A test program was conducted to determine the effectiveness of a seat belt restraint in preventing occupant movement in a rollover accident. A baseline type-2 seat belt (pelvic and torso restraint), and an improved type-2 seat belt restraint, both designed to restrict occupant motion in a rollover accident, were tested in a rollover restraints tester (RRT). Each seat belt was placed on a H-III 50th percentile male dummy and testing conducted at a single roll rate and two D-ring adjustment positions. Each test simulated what was approximately a 260 degrees per second rollover parallel to the longitudinal axis of the tractor with the top of the ROPS impacting the ground after 180 degrees of roll. Forces on the dummy's head and neck were measured, and video was taken to measure the head motion in the x-, y-, and z-axis of the dummy. The average vertical, forward, and lateral head movement in the baseline seat belt was 144, 222, and 184 mm, respectively, when the adjustable D-ring anchorage supporting the shoulder belt was in its lowest position. At the lowest D-ring height, the shoulder belt became ineffective and the seat belt performance became similar to a type-1 restraint (required for tractors with ROPS) resulting in increased vertical, forward, and lateral movement. The improved restraint reduced vertical head movement by as much as 75% without increasing head and neck loads above established injury criteria. Testing seat belts for rollover effectiveness will become increasingly important as seat belt usage on tractors with ROPS increases.     

ROPS deficiency of gray-market tractors

Many used tractors that are imported from Japan are adding to the current national inventory in the U.S. and Canada of farm tractors that lack a rollover protective structure (ROPS). Gray-market tractors are built for use by the manufacturer for a certain country but are imported against the manufacture's wishes to a second country for use there, usually as a used tractor. Gray-market tractors may lack ROPS and seatbelts, depending on the date of manufacturer. The objective of this investigation is to describe the gray market for tractors imported from Japan into the U.S. and the policy implications regarding the hazards associated with these imports. Operator manuals and warning labels are typically not written in English. Foreign manufacturers that market tractors in the U.S. have established a variety of disincentives for the importation of gray-market tractors, including issuing warnings, not servicing or providing parts for these tractors, and banning their importation through actions by the U.S. International Trade Commission. Nonetheless, a U.S. market has developed that imports and provides services and parts for gray-market tractors, and some companies provide certified ROPS on the tractors that they sell. A product safety perspective and related policies are presented as an approach to ensuring that these imports are equipped with ROPS and seatbelts.     

Temporal stability in soil water content patterns across agricultural fields

When a field or a small watershed is repeatedly surveyed for soil water content, locations can often be identified where soil water contents are either consistently larger or consistently less than the study area average. This phenomenon has been called temporal stability, time stability, temporal persistence, or rank stability in spatial patterns of soil water contents. Temporal stability is of considerable interest in terms of facilitating upscaling of observed soil water contents to obtain average values across the observation area, improving soil water monitoring strategies, and correcting the monitoring results for missing data. The objective of this work was to contribute to the existing knowledge base on temporal stability in soil water patterns using frequent multi-depth measurements with Multisensor Capacitance Probes (MCPs) installed in a coarse-texture soil under multi-year corn production. Water contents at 10, 30, 50, and 80 cm depths were measured every 10 min for 20 months of continuous observation from May 2001 to December 2002. The MCPs revealed temporal stability in soil water content patterns. Temporal stability was found to increase with depth. The statistical hypothesis could not be rejected (P < 0.0001) that data collected each 10 min, each 2 h, each day, and each week had the same temporal stability. The locations that were best for estimating the average water contents were different for different depths. The best three locations for the whole observation period were the same as the best locations for a month of observations in about 60% of the cases. Temporal stability for a specific location and depth could serve as a good predictor of the utility of this location for estimating the area-average soil water content for that depth. Temporal stability could be efficiently used to correct area-average water contents for missing data. Soil water contents can be upscaled and efficiently monitored using the temporal stability of soil water content patterns.     

A survey of tractors and rollover protective structures in Washington State

A survey of farms in Washington State was conducted to determine tractor characteristics and the presence of rollover protective structures (ROPS) in a state with more inclusive rules on tractor retrofitting than federal regulations. A total of 544 valid surveys were completed from a proportional random sample across different types of farms. Responders indicated that 58% of tractors overall were equipped with ROPS, and 42% of the tractors without ROPS were exempt from the state rules. Seatbelts on tractors equipped with ROPS were reportedly used "sometimes" or more 30% of the time, and 17% of these tractors had no seatbelt installed. Tractors used for row crop farming were significantly more likely to be equipped with ROPS than those used for tree, vine, or hops farming. Older tractors were used for fewer hours, were less likely to be ROPS-equipped, and were less likely to be operated while wearing a seatbelt. The results were consistent with a positive effect of the Washington State ROPS requirements, demonstrated by the increased percentage of ROPS-equipped pre-1976 tractors, as compared to other states, and by the difference between ROPS-equipped tractors in exempt and non-exempt types of farming. The results point to the need for prevention activities to increase seatbelt use on ROPS-equipped tractors, and for further development of practical protection for tractors operating under overhead obstacles.     

Frequency and severity of injuries to operators during overturns of farm tractors

Previous estimates of operator death from farm tractor overturn events range from 0.03 to 0.68. This study provided population-based estimates of the denominator of total farm tractor overturns and the frequency of six classes of overturn injury outcomes for tractors with and without rollover protective structures (ROPS). A 40-item telephone survey collected information from a random sample of 6,063 (8.0%) Kentucky farms about each farm's most recent overturn. A total of 551 (9.1%) farms reported overturns, and 5,512 (90.1%) reported no overturns. Injury outcomes for 443 overturns of non-ROPS tractors and 89 ROPS tractors were distributed as follows: no or minor injury (non-ROPS: 70.43%; ROPS: 82.02%), outpatient treatment (non-ROPS: 21.90%; ROPS: 9.00%), hospital admission (non-ROPS: 15.35%; ROPS: 3.37%), temporary disability (non-ROPS: 13.54%; ROPS: 14.61%), permanent disability (non-ROPS: 3.16%; ROPS: 0.00%), and death (non-ROPS: 5.42%; ROPS: 1.12%). (Percents total to more than 100 because some operators treated as outpatients were subsequently hospitalized, disabled, or died.) The observed 0.054 probability of death from overturn of non-ROPS tractors in this sample was corrected for the proportion of farms that went out of business prior to the survey and thus were excluded from the sampling frame. The adjusted 0.08 probability of death from overturn of a non-ROPS tractor is five times smaller than the NIOSH estimate of 0.40. The discrepancy lies in the much larger denominator of all non-fatal and fatal overturns than assumed previously.     

Suitability of enzyme activities for the monitoring of soil quality improvement in organic agricultural systems

There is growing interest in the applications of soil enzymes as early indicators of soil quality change under contrasting agricultural management practices. However, despite there being an abundant literature on this subject, most comparative assessments have been based on a limited number of experimental farms and, therefore, conclusions are not as robust as desired. In this study, we compare 18 pairs of organic and neighbouring conventional olive orchards in southern Spain. These sites were selected to allow the definition of the relative contributions of site-landscape features, soil type, and time since organic accreditation and tillage intensity, on the soil quality. Soils were analysed for physico-chemical properties, the activities of dehydrogenase, β-glucosidase, arylsulphatase, acid and alkaline phosphatase, and potential nitrification. The geometric mean of the assayed enzymes (GMea) was validated with an independently performed Principal Component Analysis (PCA), and used as a combined soil quality index. The effects of tillage intensity and time since organic accreditation on the improvement of soil quality were also evaluated within the subset of organic farms. Overall for the 18 sites, contrasted management practices did not differ in their impact on basic soil physico-chemical properties, except for loss of on ignition and available inorganic N which were higher and lower in organic farms, respectively. Organic management resulted in significantly higher soil enzyme activities. However, differences were not significant in some of the paired comparisons when considered individually. This highlights the need for extensive comparative assessment, as in this study, to draw clear conclusions concerning the changes to soil quality under sustainable management practices. The GMea was significantly correlated with the first axis of the PCA and shown to be appropriate for condensing the set of soil enzyme values to a sole numerical value. Soil quality changes in organic versus conventional farms, as measured by the GMea, ranged from −23% to 97%, and was highly dependent on time since organic accreditation (r = 0.88; P < 0.01). On the other hand, tillage intensity clearly tended to delay any progress in soil quality in the organic farms.     

A summary of state laws regulating youth operating farm tractors on highways

Driving farm tractors on highways is hazardous for youth due to the large speed differential between motor vehicles and agricultural vehicles, as well as recent increases in traffic volume on many rural roads. In 1994, the state of Wisconsin enacted legislation requiring youth who operate farm tractors on highways to complete a tractor and machinery certification course. We were interested in finding out whether other states have similar requirements. The purpose of this project was to collect and summarize state laws regulating youth who operate farm tractors on highways in the U.S. A systematic method was used that included an initial Lexis-Nexis database search followed by internet searches in combination with follow-up email and telephone communications when missing or unclear results were obtained. The findings show that 14 states have legislation addressing youth who operate farm tractors on highways. The content of these statutes varies, but includes driver's license or educational requirements, as well as regulations concerning the ages, locations, and/or times of day when youth may drive farm machinery on highways. This compilation of state laws will be useful information for agricultural safety professionals in designing effective outreach programs. A synthesis of the findings may also lead to the development of model legislation or inform future research efforts aimed at preventing youth farm tractor crashes on highways.     

Hydrological pathway and source area of nutrient losses identified by a multi-scale monitoring in an agricultural catchment

The objectives of the study were to identify principal hydrological pathways and source areas of N and P losses by multi-scale monitoring and to estimate total nutrient losses from the catchment. An agricultural catchment with rain-fed agriculture and irrigated paddy fields in subtropical China was monitored with regularly sampling, together with intensive sampling during and after rain storms. Regular weekly sampling showed that the N concentrations in the overland flows from the upland and paddy fields were higher than those from the streams, but lower than those in the subsurface waters. The N concentration, on average, was 10.0 mg L^− 1 in the well and 1.7 mg L^− 1 in the spring water, the former was 10.2 times as high as that in the stream waters (1.0–1.5 mg L^− 1). Nitrogen and P in the overland flows originated dominantly in particulate forms from the uplands (over 70%) and in dissolved forms from the paddy fields. Inorganic N and P dominated in the streams and subsurface waters. The intensive sampling allowed us to establish flow-nutrient concentration relationships and to extrapolate nutrient losses during rainstorms without regular sampling. The extrapolation increased the estimated nutrient losses by about 30% to 50%. The average total nutrient losses within three water years were estimated as 21 kg N ha^− 1 yr^− 1 and 1 kg P ha^− 1 yr^− 1, accounting for 9.5% and 1.4% of chemical N and P fertilizers applied to the catchment after subtracting the nutrient inputs with irrigation and rainfall. The estimation showed that paddy fields were as important as the uplands in terms of nutrient losses. These results suggest that control of soil erosion and excessive irrigation could be effective to reduce nutrient export through overland flow and subsurface flow.     

省级农业有害生物监控信息化平台结构和功能探讨

目前,信息化水平的高低已成为衡量一个行业发展的重要标志。有效控制农业有害生物的危害,保证农产品的质量、数量和生产过程安全是农业有害生物监控的根本目标。怎样把信息化的先进技术应用于植保事业,促进植保事业的发展和整体水平的提高也成为各级植保机构关注的焦点。2002年以来,河北省植保总站创建“河北植保信息网站,”对河北植保信息的收集、发布和交流起到了很好的推动作用。2006年与人大金仓公司合作创建“河北省农业有害生物信息自动化管理系统,”致力于构建整个河北省有害生物信息采集、统计、演示、分析、预警、发布、会商决策支持体系,全面提高河北省有害生物信息的监测、演示和预警信息自动化的工作水平。本文结合工作进展情况,对省级植保信息化管理平台建设和运行提出一些粗浅的看法。     

Evaluating the protective capacity of two-post ROPS for a seat-belted occupant during a farm tractor overturn

This study evaluated the effectiveness of a commercial rollover protective structure (ROPS) and size-extended ROPS in protecting a 95th percentile male operator during tractor overturns. Six rear upset tests (commercial ROPS) and ten side upset tests (commercial and size-extended ROPS) were conducted. A 95th percentile instrumented male manikin was used in all tests. Head injury criterion (HIC15), 80 g limit on resultant head acceleration, neck injury criterion (Nij), and peak axial force (extension-compression) were employed to evaluate injury potential. In all rear tests, the manikin's head impact with the ground was within the tolerance limits for head/neck injuries. Based on limited trials in the side tests, the study observed a small to moderate chance of neck injuries under the commercial and size-extended ROPS conditions; the injury risk was not statistically significant between these two test conditions. This study identified a risk of non-fatal injuries for large-size operators in side overturns, although the prevention effectiveness of commercial versus size-extended ROPS cannot be determined without further testing. These findings may have implications for future ROPS designs.     

Factors associated with the prevalence of non-ROPS tractors on farms in the U.S

Rollover protective structures (ROPS) are an effective engineering control known to prevent tractor overturn deaths, the leading cause of occupational fatalities for farmers and farm workers in the U.S. However, the use of ROPS is known to vary greatly from farm to farm. A national sample of 11,458 farm operators from the 2004 Occupational Injury Surveillance of Production Agriculture (OISPA) survey was used to assess the association between the prevalence of ROPS and ten farm operator and farm demographic variables using logistic regression. The variable were: operator's age, operator's sex, operator's education, farm sales, full- or part-time farming, acreage, type of operation, number of hired workers, number of injuries, and region. All ten variables were found to have significant associations with the prevalence of non-ROPS tractors on farms in the univariate logistic regressions. For the multivariate model, all variables except for the sex of the farm operator remained significant. Farms with less than three adult injuries, no hired workers, less than 300 acres in size, a Midwest location, and a primary farm type of tobacco, fruit and nuts, dairy, or poultry and eggs all had adjusted odds ratios of 2 or greater. Increasing the prevalence of ROPS-equipped tractors is essential for reducing the leading cause of death on farms, tractor overturns. Economic factors play a major role in the prevalence and distribution of non-ROPS tractors on farms. The identified associations can be used to effectively target areas of the U.S. for ROPS promotion activities.     

Simplified preparation of coniferyl and sinapyl alcohols

Coniferyl and sinapyl alcohols were prepared from commercially available coniferaldehyde and sinapaldehyde using borohydride exchange resin in methanol. This reduction is highly regioselective and exceptionally simple, making these valuable monolignols readily available to researchers lacking synthetic chemistry expertise.