新型土壤容重取样器的研制与应用

为了提高土壤容重取样的速度和保障取样质量,研制了新型原位土壤容重取样器,并与传统的环刀法进行了对比测试与分析.结果表明,新型的取样器具有如下优点:(1)结果可靠,T检验结果表明与传统的取样测定方法无显著差异;(2)新型原位土壤容重取样器省工省力,其工作效率比传统的环刀法高出10倍以上.(3)新型土壤容重取样器的扰动面积较小.     

Comparison of soil sampling devices used for sampling submerged soils

Abstract

Environmental sampling designed for soil chemical analyses requires precise procedural collection methods. Furthermore, soils which are submerged, represent an enigmatic sampling situation as the sample is withdrawn through the overlaying liquid layer. Contamination may arise from the liquid as well as solid material above the collected sample. A procedural problem is that close‐faced, lined samplers do not provide enough axial friction to maintain the sample within the sampler. Since the choice of proper sampling equipment is critical in site assessments, we compared two types of soil probes in this study. Both samples were nickel (Ni)‐chromium (Cr) plated having 2‐cm diameter bores. One was an open‐faced slotted sampler while the other was a closed‐faced sampler with a PETG copolyester liner. The open‐faced slotted sampler had no significantly different Ni or Cr content than did the PETG‐lined probe and maintained the soil within the sampling tube.     

Soil phosphorus testing: 2. Assessment of a rotary blade soil sampler for collecting soil samples to measure soil test phosphorus

Abstract

In Western Australia soil samples to measure soil‐test phosphorus (P) are collected November to March when soils are usually dry. Most of the soils are hard‐setting when dry and it is difficult to penetrate and collect soil samples to 10 cm using the traditional sampler, which is a 2.5 cm diameter tube that is pushed into the soil by foot. Farmers collect too few soil samples at shallow depths to measure soil‐test P. In Part 1 of this paper, it was shown that soil‐test P can vary markedly for individual soil samples collected from uniform areas in paddocks. Consequently, an adequate number of soil samples needs to be collected and bulked from defined areas to measure soil‐test P. Phopshorus accumulates near the top of the soil of (i) pastures since P fertilisers are applied to the surface of pastures, and (ii) crops sown by minimum (conservation) tillage. Crops are increasingly being sown using conservation tillage methods. Collecting too few soil samples to a shallow depth can result in large errors when estimating the current P status of soils and determining optimum fertiliser application levels. A new rotating blade method of collecting soil samples to the standard 10 cm depth for measuring soil‐test P was compared with the traditional sampler. The new sampler successfully penetrated hard‐setting soils to the standard depth and the soil samples it collected produced similar soil‐test P as the traditional sampler. Consequently, the same soil‐test P calibrations determined using the traditional sampler can also be used for the new sampler. The new sampler is, therefore, recommended for collecting soil samples to measure soil‐test P. It should have application wherever hard‐setting soils pose a problem for soil P testing.     

Reducing sampler error in soil research

Most soil sampling techniques are calibrated with standards and against each other, but the error introduced by the individuals performing each technique (sampler error) is often not addressed. We determined that sampler error explains a minimum of 5.5% of the variation in soil bulk density when using a composite coring technique. This source of error is of concern because it could easily obscure the small, but significant differences anticipated with long-term (decadal) research. We suggest three methods for increasing sampling accuracy across spatial and temporal treatments: (1) use > 5 individuals to sample each treatment; (2) consider both the concentration and pool size of soil properties (e.g. nitrate, root mass, etc.); and (3) include measurements of sampler error.     

Construction and Testing of a Simple and Economical Soil Greenhouse Gas Automatic Sampler

Quantification of soil greenhouse gas emissions requires considerable sampling to account for spatial and/or temporal variation. With manual sampling, additional personnel are often not available to sample multiple sites within a narrow time interval. The objectives were to construct an automatic gas sampler and to compare the accuracy and precision of automatic versus manual sampling. The automatic sampler was tested with carbon dioxide (CO₂) fluxes that mimicked the range of CO₂ fluxes during a typical corn-growing season in eastern Nebraska. Gas samples were drawn from the chamber at 0, 5, and 10 min manually and with the automatic sampler. The three samples drawn with the automatic sampler were transferred to pre-vacuumed vials after 1 h; thus the samples in syringe barrels stayed connected with the increasing CO₂ concentration in the chamber. The automatic sampler sustains accuracy and precision in greenhouse gas sampling while improving time efficiency and reducing labor stress.     

Influence of the Sampling Period on the Deposition Time Series of Major Ions in Bulk Precipitation

The influence of a change from daily to weekly sampling of bulk precipitation on the obtained deposition values was studied with parallel sampling for 8 months at the station of Virolahti in 2004. Due to dry deposition, the deposition values of the whole period were found to be 5–70% higher from weekly sampling than from daily sampling, the biggest difference being for K⁺, Ca²⁺, Mg⁺ and Na⁺. The collection efficiencies of the summer sampler and the winter sampler compared to the standard rain gauge were studied from daily sampling in 1991–2003 and weekly sampling in 2004–2008. The performance was best in summer and in winter with rain samples (median value 85–88%), while the median value for daily snow samples was 72%. In winter, the total sum of precipitation collected in the daily sampler and the weekly sampler was 78% and 69%, respectively. The deficit in the weekly sampler in winter was concluded to be due to evaporation, while from the summer sampler no evaporation seemed to occur. Use of the precipitation amount measured by the standard rain gauge when calculating annual precipitation-weighted mean values gave higher mean concentrations than the use of the precipitation measured by the deposition sampler itself, the biggest difference of 8–11% being in the sea-salt ions Cl^?, Mg⁺ and Na⁺. It was concluded that the concentration and deposition values measured by daily and weekly bulk sampling are incompatible, and should not be combined into the same time series.     

A simple wet-only rainfall collector

Details of an inexpensive event-actuated sampler used in the Hunter Region (Australia) Acid Precipitation Project are described. The sampler is designed for non-freezing conditions and is labor rather than material intensive. Cost of parts is approximately $120 (Australian).     

Core sampling technique for bulk density and porosity determination on a clay loam soil

Seasonal fluctuations in bulk density and porosity determined from soil cores have been observed to be independent of soil and cropping treatments on the clay and clay loam soils of southwestern Ontario. An experiment was conducted to determine if the fluctuations may be a result of inconsistencies in core sampling technique. Three core sampling techniques were compared on five dates on each of four long-term cropping treatments which provided a range in soil water contents and structure. The core sampling techniques compared were: (1) a typical hand-held, hammer driven, double cylinder core sampler with the recommended procedure; (2) a typical hand-held, hammer driven, double cylinder core sampler with an excess number of blows; (3) pressing the double cylinder core sampler into the soil hydraulically. Variations in core sampling technique significantly affected the observed values of bulk density, total porosity, and air-filled porosity at field soil water contents ranging from 12.6 to 23.8% by weight. However, hammering, compared with hydraulically pressing, the core sampler into the soil, appears to cause more distortion within the soil core which increases variability. The effect of sampling date, and its inherent effect on soil moisture, was generally greater than the effect of the core sampling techniques. Therefore, providing a consistent technique is used, observed seasonal fluctuations in bulk density, total porosity, and air-filled porosity on Brookston clay loam soil are apparently not the result of variations in the core sampling technique.     

A simple passive sampler for measuring ammonia emission in the field

A new type of passive sampler for the determination of NH₃ emission from land surfaces and manure storages was tested in a micrometereological mass balance method. The sampler consists of 2 glass tubes, each with a length of 10 cm and an internal diameter of 0.7 cm. The two glass tubes are connected in series, with one end fitted with a thin stainless steel disc having a 1 mm hole in the center. The inner surface of each glass tube is coated with oxalic acid. The results show that the passive flux sampler can be used to give accurate determinations of NH₃ emission. The passive flux sampler makes gas washing bottles, pumps, flow meters, anemometers, and electricity unnecessary and ammonia loss can be determined easily and cheaply without the requirement of a large labor force.     

土壤风蚀采沙器的结构设计与性能试验研究

土壤风蚀是全球性土地退化的主要原因之一,也是世界上许多国家和地区的主要环境问题之一。为了准确认识和掌握风沙运动规律,有效指导防止风蚀措施的选择,该文研制了适用于野外采集风蚀土壤颗粒的采沙器,并在风洞内对其等动力性、高效率性及选择性进行了验证试验。试验结果表明：所研制的采沙器满足等动力特性要求;采集率为85.6％,可作为输沙量统一修订系数;采沙器更适用于采集以跃移形式运动的土壤颗粒。     

Monitoring Particulate Matter Concentrations with Passive Samplers: Application to the Greater Thessaloniki Area

Modern European cities are characterized by high particulate matter (PM) concentrations. Unfortunately, the number of stations monitoring air pollution, especially PM, is never sufficient for the overall representation of the problem. In the present work, an inexpensive outdoor passive sampler (based on an indoor passive sampler) was developed and assembled in an effort to provide the means to extend current PM monitoring networks. The uncertainty of the sampler was tested in vitro and in vivo. Twenty such outdoor passive samplers were assembled and installed at specific locations in the Greater Thessaloniki Area and measurements of PM were carried out. The results were in good agreement with the official monitoring stations. In addition, they revealed the aggravated air quality in the center of the city and in the west suburbs.     

Study on Sampling Method of Rainfall, Throughfall, and Stemflow to Monitor the Effect of Acid Deposition on Forest Ecosystem

The use of samplers for rainfall, throughfall, and stemflow was studied in Chamaecyparis obtusa forest in Kobe to develop a suitable simplified collection method for long-term monitoring of the effect of acid deposition on the forest ecosystem. A filtrating bulk sampler, widely used in Japan due to its convenience, was modified for rainfall- and throughfall-sampling. The pH value, NH₄ ⁺- and NO₃ ^?- concns. did not change within a two-week sampling period, and the collection efficiency of the modified type relative to the wet/dry sampler was 97% (mean). The three samplers (shampoo-hat, vinyl chloride tube, and gauze type) were used for stemflow sampling. Collection efficiency of the samplers was in the order of shampoo-hat> vinyl chloride tube> gauze and that of the gauze type varied significantly with rainfall condition.     

Impact of Soil Water Content and Core Sampler Diameter at Sampling for Dry Soil Fragment‐Size Distributions

Soil conditions at sampling and the dimensions of the sample are critical factors when soil aggregation is indirectly characterized by determining the distribution of soil fragments. Our objective was to determine the effects of gravimetric soil water content and core sampler diameter (16, 54, and 84 mm) at sampling on the dry‐fragment‐size distribution of two soils (Typic Paleudalf and Typic Hapludalf) under undisturbed Festuca arundinacea L. sod and recently rototilled treatments. The 16‐mm core diameter sampler compressed the rototilled soil, and it was not appropriate for soil aggregation studies. The fragmentation of samples taken with core diameters greater than 54 mm decreased with decreasing soil water content. A greater probability of discriminating between undisturbed and fragmented silt loam or clay loam soils was observed when sampling with a 54‐mm‐diameter probe and when the soil had a mean soil water content of 237g kg^?1 or at a potential of ?0.61MPa.     

Automated analysis of gases stored in Vacutainer vials

Abstract

Trace gas research is often constrained by the number of samples to be analyzed. We report here, modifications to a commercially available headspace gas autosampler for sampling stored gas in blood collection vials (Vacutainer Brand). The sampler was modified to: a) accommodate a 0.5‐mL gastight syringe, b) accept 3‐mL Vacutainer vials, and c) ensure the syringe needle dislodged from the vial septum. Sample volumes using the modified sampler were consistent from vial to vial. For the determination of the nitrous oxide (N₂O) concentration of a known reference, we found a coefficient of variation of 3% with the modified autosampler compared to 1% with manual injections. The modification of two autosamplers has permitted analysis of 90 sample vials per day for N₂O, carbon dioxide (CO₂), oxygen (O₂), acetylene (C₂H₂), and nitrogen (N₂) gases using one gas Chromatograph with two detector systems. As a consequence, we have increased sample numbers, reduced associated labour costs and maintained analysis quality.     

SOIL SAMPLER WITH RETRIEVABLE LINER

A simple, hand-operated soil sampler based on commercially available drainpipe is described. The sampler is robust, avoids cross-contamination of samples and can penetrate to a depth of three metres. The detailed design of, and a procedure for using, the sampler are given.     

Atmospheric deposition sampler intercomparison

Two wet/dry atmospheric deposition sampler types were compared for 1 yr. The resistance required to open each of ten collectors was determined. Additionally, the opening and closing history of each sampler was recorded using a microdatalogger with a resolution of 1 min. The frequency distribution of amount of time that a collector was open was used to evaluate the comparability of opening and closing of each collector. Weekly amounts of rainfall for each of the collectors was used to determine the efficiency of collection as compared to a Belfort 5–780 weighing rain gauge. The performance of a collector as determined by the efficiency of collection and also by the distribution of frequencies of times that a sampler was exposed to precipitation were statistically different for the different sampler configurations. Disclaimer. Publication, does not signify that the contents necessarily reflect the views and policies of Department of the Army and the US Military Academy, nor does mention of trade names or commerical products constitute endorsement or recommendation for use. Not subject to copyright restrictions, work of US Government.     

土壤标本的新系列及其应用

In this paper,the structure of “double juts” soil sampler and a series of new soil samplers are introduced.The internal diameter of auger tip the sampler is less than that of sampling tube.but the external diameter of auger tip is larger than that of sampling tube,Therefore,adhesion and cutting resistance can be reduced by limiting conncetion areas between sampler and the soil,Such a new structure makes if possible to be widely used for the production of a series of special soil samplers.     

Water collection efficiency of wick samplers under steady state flow conditions

Wick samplers could be used for measurements of solute transport. Water collection efficiency of wick samplers, defined as the volume of water collected by a sampler divided by the water flux from the root zone, should be close to 100%. We used three wick samplers differing in wall height in Hydric Hapludands under constant rainfall intensity and examined the effects of the rainfall intensity and wall height on the water collection efficiency based on experimental data and a numerical analysis. The water collection efficiency of wick samplers increased with the rainfall intensity and wall height because the increase in both rainfall intensity and wall height resulted in a distribution of the total potential inside the wick sampler close to that outside the wick sampler. Furthermore, the ratio of the cross-sectional area of the drain hole to that of the cylinder must be taken into account in the design of a wick sampler.     

Atmospheric Concentrations of Sulfur Dioxide and Nitrogen Dioxide in China and Korea Measured by Using the Improved Passive Sampling Method

The results of ambient sulfur dioxide (SO₂) and nitrogen dioxide (NO₂) concentrations measured in ten cities of China and Korea by the improved passive samplers are reported. The property of this sampler is the utilization for the long-term exposure to the high level of SO₂ and NO₂. In this method, the conversion coefficients from the analytical data to the ambient concentrations were obtained from the comparison with the direct concentrations through the automatic analyzers for SO₂ and for NO₂, respectively. The interesting monthly variations were observed in the ambient SO₂ and NO₂ concentrations measured by this passive sampler method, which seems to give important information to the formation of acid rain in these countries.     

Dissolved nitrogen supersaturation of a heated effluent

A three month experimental study to evaluate the relative performance of three different designs of ‘event’ precipitation chemistry samplers was carried out at Woodbridge, Ontario beginning in August 1979. The samplers evaluated were an automatic Aerochem Metrics, ‘wet-only’ type (A), a funnel-and-bottle type (F), and a large-mouth plastic bucket with a specially-fabricated polyethylene bag insert (S). Each sampler was run in duplicate, with a sampling period of 24 hr. The results show that at sites where dry deposition is important, bulk samplers (‘F’ and ‘S’ types) yield significantly different results from the wet-only collector including rainfall amount, H⁺ , SO₄ ^?, NO₃ ^?, Na⁺, K⁺, Ca⁺⁺, and Mg⁺⁺. However, the bulk samplers, especially the ‘S’ type, are found to be satisfactory under certain conditions. For conditions which correspond to daily rainfall less than 2.8 mm and windier and drier sampling, there is even evidence of dry contamination of the wet-only type sampler.