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91.
The study was conducted to assess the potential of Norwegian agricultural ecosystems to sequester carbon (C) based on the data from some long-term agronomic and land use experiments. The total emission of CO2 in Norway in 1998 was 41.4 million metric ton (MMT), of which agriculture contributed only 0.157 MMT, or <0.4% of the total emissions. With regards to methane (CH4) and nitrous oxide (N2O) gases, however, agricultural activities contributed 32.5% and 51.3% of their respective emissions in Norway. The soil organic carbon (SOC) losses associated with accelerated soil erosion in Norway are estimated at 0.475 MMTC yr–1. Land use changes and soil/crop management practices with potential for SOC sequestration include conservation tillage methods, judicious use of fertilizers and manures, use of crop residues, diverse crop rotations, and erosion control measures. The potential for SOC sequestration is 0.146 MMTC yr–1 for adopting conservation tillage, 0.011–0.035 MMTC yr–1 for crop residue management, 0.026 MMTC yr–1 for judicious use of mineral fertilizer, 0.016–0.135 MMTC yr–1 for manure application, and 0.036 MMTC yr–1 for adopting crop rotations. The overall potential of these practices for SOC sequestration ranges from 0.591 to 1.022 MMTC yr–1 with an average value of 0.806 MMTC yr–1. Of the total potential, 59% is due to adoption of erosion control measures, 5.8% to restoration of peat lands, 21% to conversion to conservation tillage and residue management, and 14% to adoption of improved cropping systems. Enhancing SOC sequestration and improving soil quality, through adoption of judicious land use and improved system of soil and crop management, are prudent strategies for sustainable management of soil, water and environment resources.Readers should send their comments on this paper to:
bhaskarn ath@aol.com within 3 months of publication of this issue. 相似文献
92.
D. Jasso de Rodríguez J. L. Angulo-Sánchez R. Rodríguez-García 《Journal of Polymers and the Environment》2006,14(1):37-47
Guayule is a shrub native to Mexico growing in semiarid lands, that may be incorporated into the semiarid region production
system as a complement for annual crops. The possibility to develop this natural resource as a sustainable industrial source
of natural rubber, may improve the socio-economical level of people living at the guayule region and favor the agricultural
development near the US-Mexico border. Despite the existence of natural stands in Mexico with guayule plants of different
rubber content, a program envisaging selection of plants with high rubber synthesis potential joined to agronomic management
practices are required. This could achieve the rubber yield needed to guarantee a constant supply of raw material for an industrial
processing plant. This paper reviews R&D work carried out in Mexico for the last 25 years, including genetic aspects and evaluation
of guayule response to environmental and agronomic factors. Relevant results showed plants with up to 21% rubber content and
the existence of diploid plants, which could facilitate future plant breeding programs. 相似文献
93.
Jen‐Yang Lin Shaw L. Yu Tsu‐Chuan Lee 《Journal of the American Water Resources Association》2000,36(5):989-1001
ABSTRACT: For many years, a commonly used strategy for source water protection in Taiwan has been setting up arbitrary, fixed‐width buffer zones near sensitive waters, such as water‐supply reservoirs, and prohibiting any development in their watersheds. However, such regulations are now often viewed as infringing by the government on landowners' property rights, a situation that has led to citizen protests. This paper describes a proposed strategy that is water‐quality based and uses a quantitative zoning approach. A reservoir's watershed is divided into several zones beginning from the normal water line to the divide. Different levels of best management practices (BMPs) are required for controlling runoff pollution in different zones. The layout of the management zones is based on a number of factors such as reservoir classification, water quality conditions, and physical characteristics of the watershed. The goal of promoting such an approach is to try to balance the needs of watershed development and water quality protection. A case study using the Tapu Reservoir Watershed in Northern Taiwan as an example for illustrating the proposed zoning approach is presented. 相似文献
94.
I. Lorenzoni A. Jordan D. Favis-Mortlock D. Viner J. Hall 《Regional Environmental Change》2001,2(3):106-117
The weight of scientific evidence suggests that human activities are noticeably influencing the world's climate. However,
the effects of global climate change will be unevenly spread, due to local variations in vulnerability and adaptive capacity.
Using downscaled projections of future UK climates over the next 50 years, this paper investigates the impacts of, and possible
responses to, climate change in one small area in eastern England, selected as a test-bed for sustainable agriculture. It
shows that local agricultural systems are vulnerable to changes in the climate. At present, however, these considerations
have a limited effect on agricultural operations, which are mainly driven by short-term events and 'non-climate' policies,
such as agricultural price support. The capacity of agricultural systems to adapt successfully to climate change will be determined
by the ability of producers to integrate climate change into their planning strategies with a view to ultimately ensuring
sustainable agricultural practices in the long term.
Electronic Publication 相似文献
95.
Accidents involving contractors continue to occur with regular frequency. By using the standard set within the PSM 29 CFR 1910.119(h) regulations, it has been identified that certain aspects of the way contractors do work are not up to the stipulated regulatory requirements especially regarding matters like not providing mandatory personal protective equipment (PPE) to the workers, not discussing hazards related to handling procedures with the workforce and improper control of non-routine activities during changes in shifts. The PSM 29 CFR 1910.119(h) regulations promulgated in 1992 provides standards that covered processes to obtain and evaluate data regarding contractors' health and safety programs as well as the contractors' performance evaluation. Many of the accidents involving contractors are direct result of poor training of contractors and/or poor control of the contracted work. Even though most organizations have their own contractor management systems, there are issues in meeting the requirements of PSM. The PSM standard only state “what to do” not “how to do it”. This is known as self-regulatory policy which depends on the industries understanding to interpret the standard that also contribute to this problem. This paper presents a structured and easy technique to plan and implement a practical and comprehensive contractors' management system in process industries that will comply with OSHA CFR 1910.119. A model has been developed based on this technique and its application has been tested in a pilot plant for compliance to PSM regulation. The model is beneficial to the process industries as any deficiencies in the PSM contractors' management program will be highlighted by the model which will then easily correct the identified deficiency so as to minimize and prevent catastrophic accidents. 相似文献
96.
97.
Anna‐Katharina Hornidge Lisa Oberkircher Bernhard Tischbein Gunther Schorcht Anik Bhaduri Ahmad M. Manschadi 《Natural resources forum》2011,35(4):251-268
The Khorezm region is located in the northwest of Uzbekistan, approximately 350 km from the current shore of the Aral Sea. It comprises a large‐scale irrigation system that conveys water from the river Amu Darya to agricultural land cropped mainly with cotton, wheat, and rice. Khorezm's water resources are vulnerable as they depend on upstream developments and are indispensable to rural livelihoods and state budgets. Since water scarcity is expected to increase in the future, sustainable water management is a necessity. Hence, the objectives of the paper are to: (1) conceptualize the distinctive features of water management in Khorezm; (2) provide an integrated analysis of water management by establishing linkages between society, technical infrastructure, and the bio‐physical environment; and (3) make policy and technology recommendations for improved water management. To conceptualize water management in Khorezm, the paper distinguishes three types of practices: formal practices, strategic practices, and discursive practices. Based on these, it presents an analysis of water management on the state water management level, the water user association level, and the farmer and field level. For each level, recommendations are given. The paper concludes that elements of integrated water resources management (IWRM) such as transparency, accountability, participation, and technical efficiency are relevant to improve water management in Khorezm, as elsewhere. In addition, it underlines the need to create legal space for agency and innovation. Technical tools such as models are increasingly important for facilitating transparency and enabling agents to access and make use of information across the management hierarchy. 相似文献
98.
The prevalence of forestry practices such as thinning and pruning have gradually decreased since the 1980s. Researchers have noted an increased flood risk with decreased forestry practices for coniferous plantations in Japan on the basis of infiltration and overland flow measurements at a plot scale (typically several square meters). However, no studies have examined changes in peak flow with decreased forestry practices at a watershed scale (typically several tens or hundreds of square kilometers) even though flood disasters generally occur at this scale in Japan. We examined changes in frequency distributions of daily precipitation (P) and runoff (Q) during the period 1979-2007 at the Terauchi watershed, where forestry practices are known to have decreased. For this purpose, we divided P and Q data into 14 and 15 classes according to the magnitude, respectively, and examined changes in the frequency for each class during the period. We observed no significant increasing trend for any P or Q class. Even when taking into account the effect of interannual variations in precipitation on the frequency for each Q class, there was no significant increasing trend in the frequencies except for two Q classes with moderate Q values. These results suggest that the increase in flood risk due to decreased forestry practices might be less than expected. 相似文献
99.
Vassilios A. Tsihrintzis Hector R. Fuentes Rao K Gadipudi 《Journal of the American Water Resources Association》1996,32(2):317-331
ABSTRACT: Agricultural and urban activities in the West Wellfield Interim Protection Area (WWIPA), located in West Dade County in South Florida, have the potential to impact both the environmentally sensitive Everglades and the Biscayne Aquifer. The Hydrological Simulation Program-FORTRAN (HSPF) is used to simulate surface runoff, ground water recharge, and transport of sediments, nutrients, and pesticides in the WWIPA, as a basis to quantify impacts and evaluate alternatives. Presented are four model test runs that consider current conditions, the effect of future urbanization of the agricultural land, as well as two preventive actions to minimize pollution levels. Preventive actions include application of minimum required rates of fertilizers and replacement of fertilizers by sewage sludge. Model results show that under current practices, sediments, nutrients, and pesticides are present in surface runoff and nutrients enter the ground water, and that both urbanization and preventive actions result in pollutant reductions. 相似文献
100.
Christopher A. Ellison Quentin D. Skinner Katta J. Ready 《Journal of the American Water Resources Association》2006,42(1):55-68
Sage Creek in south‐central Wyoming is listed as impaired by the U.S. Environmental Protection Agency (USEPA) due to its sediment contribution to the North Platte River. Despite the magnitude of sediment impacts on streams, little research has been conducted to characterize patterns of sediment transport or to model suspended sediment concentration in many arid western U.S. streams. This study examined the relationship between stream discharge and suspended sediment concentration near the Sage Creek and North Platte River confluence from 1998 through 2003. The objectives were to determine patterns of stream discharge and suspended sediment concentration, produce a sediment prediction model, and compare sediment concentrations for the six‐year period. Stream discharge and suspended sediment transport responded rapidly to convective storms and spring runoff events. During the study period, events exceeding 0.23 m3/s accounted for 92 percent of the sediment load, which is believed to originate from erodible headwater uplands. Further analysis of these data indicates that time series modeling is superior to simple linear regression in predicting sediment concentration. Significant increases in suspended sediment concentration occurred in all years except 2003. This analysis suggests that a six‐year monitoring record was insufficient to factor out impacts from climate, geology, and historical sediment storage. 相似文献