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61.
Soil carbon dynamics in cropland and rangeland 总被引:36,自引:0,他引:36
Lal R 《Environmental pollution (Barking, Essex : 1987)》2002,116(3):353-362
Most soils in the Midwestern USA have lost 30 to 50% of their original pool, or 25 to 40 Mg C/ha, upon conversion from natural to agricultural ecosystems. About 60 to 70% of the C thus depleted can be resequestered through adoption of recommended soil and crop management practices. These practices include conversion from plow till to no till, frequent use of winter cover crops in the rotation cycle, elimination of summer fallow, integrated nutrient management along with liberal use of biosolids and biological nitrogen fixation, precision farming to minimize losses and enhance fertilizer use efficiency, and use of improved varieties with ability to produce large root biomass with high content of lignin and suberin. The gross rate of soil organic carbon (SOC) sequestration ranges from 500 to 800 kg/ha/year in cold and humid regions and 100 to 300 kg/ha/year in dry and warm regions. The rate of SOC sequestration can be measured with procedures that are cost effective and credible at soil pedon level, landscape level, regional or national scale. In addition to SOC, there is also a large potential to sequester soil inorganic carbon (SIC) in arid and semi-arid regions. Soil C sequestration has numerous ancillary benefits. It is truly a win-win situation: extremely cost-effective, and a bridge to the future until alternative energy options take effect. 相似文献
62.
The effects of three insecticides, dieldrin, dimethoate and permethrin, on the growth of a holotrichous ciliate, Tetrahymena pyriformis, were studied for 5 days. The ciliate was very sensitive to dieldrin and dimethoate. Both these insecticides produced approximately 81% and 84% inhibition of growth within two days. Dieldrin caused rounding of cells, while dimethoate induced cell lysis. Dimethoate also triggered a general mucocyst discharge. Of the three insecticides, permethrin was the least toxic and induced no morphological alterations. 相似文献
63.
Kumar T Stanley VA Lal AA Balasubramanian M Pillai KS 《Journal of environmental biology / Academy of Environmental Biology, India》2002,23(4):407-410
Alloxan-induced diabetic rats were treated with multiple herbal preparation besides a control group receiving distilled water. The levels of glucose and alkaline phosphatase (ALP) increased abnormally in the alloxan treated group and the same were normalized upon treatment with the herbal preparation. The levels of blood urea nitrogen (BUN), alanine aminotransferase (ALT), protein and albumin in all groups remained unaltered. However, weekly body weight gain which got significantly altered in the alloxan-treated group was normalized by treatment with the herbal preparation. On the whole, a profound hypoglycemic effect was observed by the multiple herbal treatment in the diabetic rats. 相似文献
64.
65.
Srivastav Arun Lal Dhyani Rajni Ranjan Manish Madhav Sughosh Sillanpää Mika 《Environmental science and pollution research international》2021,28(31):41576-41595
Environmental Science and Pollution Research - Warming of the earth is considered as the major adverse effect of climate change along with other abnormalities such as non-availability of water... 相似文献
66.
67.
Global warming risks from emissions of green house gases (GHGs) by anthropogenic activities, and possible mitigation strategies of terrestrial carbon (C) sequestration have increased the need for the identification of ecosystems with high C sink capacity. Depleted soil organic C (SOC) pools of reclaimed mine soil (RMS) ecosystems can be restored through conversion to an appropriate land use and adoption of recommended management practices (RMPs). The objectives of this paper are to (1) synthesize available information on carbon dioxide (CO2) emissions from coal mining and combustion activities, (2) understand mechanisms of SOC sequestration and its protection, (3) identify factors affecting C sequestration potential in RMSs, (4) review available methods for the estimation of ecosystem C budget (ECB), and (5) identify knowledge gaps to enhance C sink capacity of RMS ecosystems and prioritize research issues. The drastic perturbations of soil by mining activities can accentuate CO2 emission through mineralization, erosion, leaching, changes in soil moisture and temperature regimes, and reduction in biomass returned to the soil. The reclamation of drastically disturbed soils leads to improvement in soil quality and development of soil pedogenic processes accruing the benefit of SOC sequestration and additional income from trading SOC credits. The SOC sequestration potential in RMS depends on amount of biomass production and return to soil, and mechanisms of C protection. The rate of SOC sequestration ranges from 0.1 to 3.1 Mg ha(-1) yr(-1) and 0.7 to 4 Mg ha(-1) yr(-1) in grass and forest RMS ecosystem, respectively. Proper land restoration alone could off-set 16 Tg CO2 in the U.S. annually. However, the factors affecting C sequestration and protection in RMS leading to increase in microbial activity, nutrient availability, soil aggregation, C build up, and soil profile development must be better understood in order to formulate guidelines for development of an holistic approach to sustainable management of these ecosystems. The ECBs of RMS ecosystems are not well understood. An ecosystem method of evaluating ECB of RMS ecosystems is proposed. 相似文献
68.
Lignite fly ash (LFA), being alkaline and endowed with excellent pozzolanic properties, a silt loam texture, and plant nutrients,
has the potential to improve soil quality and productivity. Long-term field trials with groundnut, maize, and sun hemp were
carried out to study the effect of LFA on growth and yield. Before crop I was sown, LFA was applied at various doses with
and without press mud (an organic waste from the sugar industry, used as an amendment and source of nutrients). LFA with and
without press mud was also applied before crops III and V were cultivated. Chemical fertilizer, along with gypsum, humic acid,
and biofertilizer, was applied in all treatments, including the control. With one-time and repeat applications of LFA (with
and without press mud), yield increased significantly (7.0–89.0%) in relation to the control crop. The press mud enhanced
the yield (3.0–15.0%) with different LFA applications. The highest yield LFA dose was 200 t/ha for one-time and repeat applications,
the maximum yield being with crop III (combination treatment). One-time and repeat application of LFA (alone and in combination
with press mud) improved soil quality and the nutrient content of the produce. The highest dose of LFA (200 t/ha) with and
without press mud showed the best residual effects (eco-friendly increases in the yield of succeeding crops). Some increase
in trace- and heavy-metal contents and in the level of γ-emitters in soil and crop produce, but well within permissible limits,
was observed. Thus, LFA can be used on a large scale to boost soil fertility and productivity with no adverse effects on the
soil or crops, which may solve the problem of bulk disposal of fly ash in an eco-friendly manner. 相似文献
69.
Ram M. Shrestha S.C. Bhattacharya Sunil Malla 《Journal of environmental management》1996,46(4):359-372
This paper presents a review of energy use in 22 selected countries of Asia and estimates the anthropogenic emission of sulphur dioxide (SO2) for the selected countries, both at national and disaggregated sub-country regional levels. The paper also makes a comparative assessment of the Asian countries in terms of SO2emission intensity (i.e. emission per GDP), emission per capita and emission density (i.e. emission per unit area). Total SO2emission in the region was estimated to be about 38 million tons in 1990. Five countries, China, India, South Korea, Japan and Thailand, accounted for over 91% of the regional SO2emission. Coal use had the dominant share (81%) of the total emission from the region. Among the economic sectors, industry contributed the largest share (49%) to the total emissions of the selected countries as a whole, followed by the power sector (30%). These findings suggest the need for mitigation strategies focussed on the industry and power sectors of the major emitting countries in Asia. 相似文献
70.
Linking Conservation and Development: An Analysis of Local People’s Attitude Towards Koshi Tappu Wildlife Reserve, Nepal 总被引:1,自引:0,他引:1
Ram K. Shrestha Janaki R. R. Alavalapati 《Environment, Development and Sustainability》2006,8(1):69-84
Factors influencing local people’s attitudes towards conservation of the Koshi Tappu Wildlife Reserve (KTWR) are analyzed
using an ordered logit model. The results indicate that households living closer to the KTWR are more likely to reveal negative
attitude towards conservation. Similarly, respondents from larger households tend to show negative conservation attitude.
Educated respondents and farmers are likely to demonstrate a positive conservation attitude. The results consistently show
that households with poor socioeconomic status and greater dependence on the KTWR for firewood, fodder, and raw materials
are likely to possess a more negative attitude towards conservation. Poor households may not necessarily be less concerned
about conservation, although institutional settings and abject poverty near protected areas appear to affect their attitudes.
Sustainable management of protected areas and local support for natural resource conservation would require socioeconomic
development. 相似文献