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1.
A sample accountability quality assurance (QA) program is described for a field and laboratory research effort which resulted in collection of approximately 2000 samples for analysis by several EPA and contractor laboratories. A QA program was specifically developed for this research program to include sample transfer from collection site to storage maintenance, record development, transfer to researchers, and sample tracking at all stages. A sample identification system and sample custody records are described for field and laboratory application. The functions of a sample coordinator are also described as relating to sample custody, coordination of sample analysis with researchers, and development of computer record files to facilitate research and sample tracking.  相似文献   

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Water resources are essential for economic and cultural development of a territory. Both economic development and the health of the people depend on the provision of pure water. Scientifically founded plans of water resources use and conservation should be based on a balance approach to the assessment of available water supply sources and, on the forecast of their interconnected change in the future in a close association with the forecast of the whole economy and culture of the studied region. In the future the main threat to the normal development of the economy and life will not be water deficiency but the conversion of rivers, lakes and other water supply sources into sewers. Therefore it is proposed that there be a complete cessation of sewage discharge (even of the so-called purified) into water supply sources while drawing up long-term water management balances.  相似文献   

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An account is given of a study of the size and diversity of populations of Clostridium pasteurianum and C. acetobutylicum in representative soils sampled at various latitudes and altitudes within the U.S.S.R. Evidence is presented to show that the two species are well adapted to soil and climatic factors in terms of the relative dominance of the two species and in terms of differences in their growth-temperature characteristics, carbohydrate utilization and fermentation products, nitrogen fixation and the comparative chemistry of their cells. In all of these characteristics, C. pasteurianum was more variable than C. acetobutylicum.  相似文献   

6.
? Records available through the United State Department of Agriculture's Current Research Information System (CRIS) document around 30,000 publicly supported research projects in agriculture, forestry, food and nutrition, and natural resources. Projects originated by the USDA, land-grant institutions, state agriculture experiment stations, schools of forestry, and cooperating schools of veterinary medicine that receive some type of federal funding are cataloged. A recent search for all projects in the database related to “composting” (requested by Richard Kashmanian of the U.S. EPA's Office of Policy, Planning and Evaluation) unearthed 220 reports. Compost Science & Utilization editors categorized these current or recently completed projects and selectively edited the following entries as a representative sampling of the information available through this resource.  相似文献   

7.
There are a variety of opportunities to change land and forest management and, at the same time, create a positive impact on the current use of fossil energy. To the extent that these opportunities can be captured, they address the root cause of greenhouse warming-fossil fuel emissions-while, at the same time, improving economic opportunities, ecosystem productivity, and environmental conditions over broad areas. The need for better markets to absorb biomass energy, plus research to make biomass conversion more efficient, is probably the most important deterrent to achieving these possibilities.  相似文献   

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Molecular tritium deposition occurred in all soils tested. Deposition velocities for tritium ranged from 0.0025 to 0.11cm s?1 with a geometric mean of 0.028 cm s?1. Coring surveys from six different sites showed that deposition rates were highest in the upper 20 cm of soil, with little activity evident below this depth. Plant cover did not appear to have a strong direct influence on the profile of tritium deposition activity.  相似文献   

10.
Double cropping of soybean has progressed less rapidly in the U.S. Southeastern Coastal Plains than expected by the ample rainfall and long frost-free season. Post-emergence herbicides, the management of plant residues to reduce water use by cover crops, and a no-till planter with a combination subsoiler are the innovations that have facilitated this new production. Full-season soybean (Glycine max L.) was planted following a grazed cover crop of winter rye (Secale cereale L.) or late-season soybean was planted following winter wheat harvest. In both cases, a special planter was used with an integral subsoil shank ahead of the opener. Full-season soybean under conservation tillage produced yields equal to or better than yields in conventional clean tillage. In a dry summer, soybean yields under conservation tillage exceeded conventional tillage because of suppressed early biomass production which conserved stored soil water and favored growth during the reproduction phase of the crop-cycle. Late-season soybean yields behind wheat favored the conservation tillage practice of in-row subsoil-planting into stubble. However, planting in burned-off wheat stubble produced the highest yields in this study. In a dry spring, the cover crop accelerated soil water use which resulted in lower soybean yields under conservation tillage. Comparisons of 76 vs. 97 cm row spacing were inconclusive, but the trend suggests that wider rows conserve water under periods of drought and that the narrower-row configuration favors adequate water regimes.  相似文献   

11.
本文为考察报告,叙述了美国水稻和畜牧业生产情况,美国对全球稻田和反刍动物排放甲烷量的估计,以及美国对此农业源甲烷排放的研究情况。  相似文献   

12.
Global atmospheric concentrations of mercury (Hg) appear to be increasing and with it the potential for ecosystem exposure and ecological effects. From 1990 to 1993 we examined U. S. arctic ecosystems over a broad spatial scale to develop baseline information on current concentrations of trace elements, heavy metals (including Hg), persistent organic compounds, and radionuclides in various components of the terrestrial and freshwater biosphere. Matrices reported here include, vegetation (lichens and mosses) and lake sediments. Total Hg in two lichen and two moss species from Alaska were generally low (0.02–0.112 μg/g dw), compared to reported values from other arctic locations and showed a statistically significant negative relationship between total Hg content and distance from the marine coastline.210Pb dated sediment cores indicated that average preindustrial total Hg accumulation rates were over four times greater in arctic Schrader lake than in subarctic Wonder Lake. Both lakes indicated a small increase (5–8%) in total Hg flux to the sediments during the last 145 years, much smaller than similar increases in total mercury for lakes in the north central U. S. The likely source of recent increases in Hg in these Alaskan ecosystems is long range atmospheric transport. While we can detect increases in mercury in lake sediments likely due to anthropogenic activities, values are low and there appears to be no immediate threat to terrestrial environments and inland freshwaters of arctic Alaska from long range atmospheric transport and deposition of Hg.  相似文献   

13.
Rice can yellow during storage if moisture levels and temperatures are allowed to increase. This postharvest yellowed (PHY), or stackburn, rice is reduced in value but no study has investigated the inherent potential within rice germplasm for limiting PHY. To screen a large number of cultivars for propensity to PHY, a laboratory method for PHY using a small amount of rice was used. Ninety‐eight popular southern U.S. rice cultivars were yellowed under laboratory conditions. Additional samples of the low‐yellowing and high‐yellowing cultivars were retested after two and three years of storage as rough rice using higher amounts and larger containers. All cultivars showed greater color change with the higher amounts of rice and when yellowed as milled rather than as rough rice. Length of time of storage and storage temperature did not affect the degree of PHY. The low‐ and high‐yellowing groups remained distinguishable but the overall high level of coloring in southern U.S. rice cultivars indicates that a more diverse germplasm should be investigated to increase the likelihood of identifying low‐PHY cultivars.  相似文献   

14.
The status of air pollution control technology for coal fired industrial and power plant boilers has been surveyed. Lime and limestone based scrubbers are capable of removing as much as 93% of flue gas SO2 at facilities supplying 800 MW power. A sludge containing SO x ions must be discarded in the process, usually requiring landfill or a settling pond. The Wellman-Lord, thiosorbic, and citrate processes are capable of producing salable products instead of the sludge. They are successful (85 to 90% removal) on demonstration-scale units. The Wellman-Lord process is currently being tested on large-scale coal fired units. Electrostatic precipitators, the mahor control device for removing particulates, can eliminate 99.5% of the fine particles. Fabric filtration can remove 99.9% and is more efficient in the 0.2 to 2μm size range than ESPs. Utilization of fabric filters is expected to increase significantly from its present 5% of the particulate removal market. Nitrogen oxide concentrations in coal fired systems are usually reduced by modification of the combustion system. No significant NO x reduction on full-scale boilers has yet been reported, but demonstrations are planned over the next few years. Various process capital and annualized costs are reported for SO2 and particulate removal systems. The status of fluidized bed combustion, fuel desulfurization, conversion of coal to gaseous and liquid fuels, and flue gas denitrification is also discussed. Part A deals with S emission; Part B with NO x , particulates, and combined systems.  相似文献   

15.
Eight conservation tillage methods were evaluated for maize (Zea mays L.) production and were related to water conserved, soil strength, plant stand, plant nutrient status, and methods of managing crop residues on Norfolk loamy sands (Typic Paleudults) in the U.S. southeastern coastal plain. This study summarizes 10 site-years of data collected from 1978 through 1982.

Seasonal soil-water balance and crop residue management largely determined the success of maize production under conservation tillage. Autumn subsoiling increased winter forage and maize production under both conventional and conservation tillage. When early-season rainfall was limited, water extraction by a winter cover crop or winter weeds often reduced early-season growth and yield of maize under conservation tillage. For adequate stands, increased seeding rates and effective weed-, rodent-, bird- and insect-control were all necessary.

Under adequate water regimes, conventional tillage resulted in greater yields at low levels of nitrogen, but maximum yields occurred regardless of tillage system, when 200 kg ha−1 were applied. Conventionally-tilled maize generally resulted in higher yields than conservation tillage production. The only significant increase for conservation tillage occurred under non-irrigated conditions in 1981 during severe drought. The interactive soil and climatic factors which have impact on conservation tillage in this physiographic region were identified.  相似文献   


16.
We compiled and summarized current literature on S input/output budgets for intensively studied sites and soil plots in the U.S. and Canada and found S retention to be related to both soil order and extent of the last glaciation (Wisconsinan). Zero net retention is associated with Spodosols and was found only at sites north of the limit of Wisconsinan glaciation. Sites south of the limit of glaciation appear to be retaining from 20 to 90% of incoming S. These findings support the hypothesis that there exist regional variations in S retention in North America. Such variations are important in determining and predicting effects of acidic deposition on surface water chemistry.  相似文献   

17.
介绍了荷兰王国家禽业的发展概况及现代饲养新工艺。从鸡舍建筑工艺、笼具设施、营养研究与应用及鸡粪深加工处理的角度阐述了家禽饲养新工艺对环境保护的重要作用,说明了荷兰家禽业得以持续健康发展的关键在于重视环境保护。  相似文献   

18.
The annual average concentration of Cl in Cayuga Lake, NY, has decreased from a value of approximately 102 mg L?1 in 1970, when the discharge of NaCl fines from an adjoining rock salt mine was discontinued, to a concentration of approximately 46 mg L?1 in 1988. A complete-mixed model for Cl concentration accurately simulated this decrease in concentration, establishing that the decrease was the result of an abrupt reduction in loading. The time course of the decrease strongly supports the position that the high Cl concentrations that prevailed in the lake in the late 1960's were largely a result of the discharge from the mining facility, and not due to the input of enriched groundwater as previously hypothesized. The predicted steady-state Cl concentration associated with the complete flushing of the mining facility input, expected in about the year 2000, is approximately 32 mg L?1. Further, the model analysis supports previous speculation that the major source of material loading to the lake, the Seneca River, ‘short-circuits’ to the outlet; i.e., this tributary should not be included in material budgets for the lake.  相似文献   

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Rog B. Parsons 《Geoderma》1978,21(1):25-39
The development and distribution of soils in the Coast Range and Klamath Mountains are related to geomorphic surfaces and slope gradients. Soils over basalt, studied in the Coast Range, were formed in transported materials and include examples of more than a half dozen great groups of the Alfisol, Inceptisol, Mollisol, and Ultisol orders. Distribution patterns of the soils can be related to active slopes, metastable slopes, pediments, ridge tops, flood plains, and alluvial fans. Variables among the factors of soil formation in the Coast Range are chiefly geomorphic surfaces and parent materials.Soils of a lithosequence of pyroclastics, granite and schist in the Klamath Mountains include examples of great groups in the Entisol, Inceptisol, and Mollisol orders. All soils from pyroclastics have argillic horizons, those from granite lack argillic horizons, and those from schist lack argillic horizons except on relatively stable surfaces. Average thicknesses of soils over saprolite range from 76 cm over granite and schist to 150 cm over pyroclastics.Lithologic discontinuities are common in both mountain areas. Field techniques for identification, described briefly, include stone lines, irregular distribution of rock fragments with depth, thicknesses of weathering rinds on rock fragments, and the lateral extensions of soil horizons.  相似文献   

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