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81.
The international competitiveness of the New Zealand (NZ) dairy industry is built on low cost clover-based systems and a favourable temperate climate that enables cows to graze pastures mostly all year round. Whilst this grazed pasture farming system is very efficient at producing milk, it has also been identified as a significant source of nutrients (N and P) and faecal bacteria which have contributed to water quality degradation in some rivers and lakes. In response to these concerns, a tool-box of mitigation measures that farmers can apply on farm to reduce environmental emissions has been developed. Here we report the potential reduction in nutrient losses and costs to farm businesses arising from the implementation of individual best management practices (BMPs) within this tool-box. Modelling analysis was carried out for a range of BMPs targeting pollutant source reduction on case-study dairy farms, located in four contrasting catchments. Due to the contrasting physical resources and management systems present in the four dairy catchments evaluated, the effectiveness and costs of BMPs varied. Farm managements that optimised soil Olsen P levels or used nitrification inhibitors were observed to result in win-win outcomes whereby nutrient losses were consistently reduced and farm profitability was increased in three of the four case study farming systems. Other BMPs generally reduced nutrient and faecal bacteria losses but at a small cost to the farm business. Our analysis indicates that there are a range of technological measures that can deliver substantial reductions in nutrient losses to waterways from dairy farms, whilst not increasing or even reducing other environmental impacts (e.g. greenhouse gas emissions and energy use). Their implementation will first require clearly defined environmental goals for the catchment/water body that is to be protected. Secondly, given that the major sources of water pollutants often differed between catchments, it is important that BMPs are matched to the physical resources and management systems of the existing farm businesses. 相似文献
82.
Sébastien Desbureaux 《Conservation biology》2021,35(5):1615-1626
Arbitrary modeling choices are inevitable in scientific studies. Yet, few empirical studies in conservation science report the effects these arbitrary choices have on estimated results. I explored the effects of subjective modeling choices in the context of counterfactual impact evaluations. Over 5000 candidate models based on reasonable changes in the choice of statistical matching algorithms (e.g., genetic and nearest distance mahalanobis matching), the parametrization of these algorithms (e.g., number of matches), and the inclusion of specific covariates (e.g., distance to nearest city, slope, or rainfall) were valid for studying the effect of Virunga National Park in Democratic Republic of the Congo on changes in tree cover loss and carbon storage over time. I randomly picked 2000 of the 5000 candidate models to determine how much and which subjective modeling choices affected the results the most. All valid models indicated that tree cover loss decreased and carbon storage increased in Virunga National Park from 2000 to 2019. Nonetheless, the order of magnitude of the estimates varied by a factor of 3 (from −4.78 to −13.12 percentage points decrease in tree cover loss and from 20 to 46 t Ce/ha for carbon storage). My results highlight that modeling choices, notably the choice of the matching algorithm, can have significant effects on point estimates and suggest that more structured robustness checks are a key step toward more credible findings in conservation science. 相似文献
83.
Nonpoint-Source Agricultural Hazard Index: A Case Study of the Province of Cremona, Italy 总被引:1,自引:0,他引:1
This paper reports the results of a study aimed at the evaluation of the hazard level of farming activities in the province
of Cremona, Italy, with particular reference to groundwater. The applied methodology employs a parametric approach based on
the definition of potential hazard indexes (nonpoint-source agricultural hazard indexes, NPSAHI). Two categories of parameters
were considered: the hazard factors (HF), which represent all farming activities that cause or might cause an impact on groundwater
(use of fertilizers and pesticides, application of livestock and poultry manure, food industry wastewater, and urban sludge),
and the control factors (CF), which adapt the hazard factor to the characteristics of the site (geographical location, slope,
agronomic practices, and type of irrigation). The hazard index (HI) can be calculated multiplying the hazard factors by the
control factors and, finally, the NPSAHI are obtained dividing HI into classes on a percentile basis using a scale ranging
from 1 to 10. Organization, processing, and display of all data layers were performed using the geographical information system
(GIS) ArcView and its Spatial Analyst extension. Results show that the potential hazard of groundwater pollution by farming
activities in the province of Cremona falls mainly in the fifth class (very low hazard). 相似文献
84.
It is difficult to make general recommendations that apply to all ecosystems. There is still a relative dearth of studies
that allow the manager or visitor to come up with specific practices that are the best for their area. The preferred method
of disposal remains to dig a small hole (cat hole) and bury the waste. Other site specific methods are also discussed.
Treatment of drinking water has become standard practice for most backcountry travel. With such treatment, there is little
evidence currently to suggest that the health hazard to humans is great enough to impose further regulation in areas currently
using cat holes. 相似文献
85.
Kaufman MM 《Environmental management》2000,26(1):89-97
/ To test the effectiveness of Michigan's soil erosion control law, 30 construction sites were evaluated in the east-central part of the state. The analytical framework lumped nine best management practices (BMPs) most closely related to the law into three categories: slope stabilization, soil stabilization, and water management. All sites were in the land clearing or foundation/framing stage of construction and were evaluated within 2 days after a rainfall event. Only four of the sites performed above the mean of the scoring scale, with the categorical scoring of BMPs indicating the worst performance for slope stabilization measures. The poor results suggest a failure to integrate scientific knowledge of erosion control with policy. A fundamental problem is the lack of basic site data on soil, topography, and hydrology, resulting in the incorrect application of BMPs, such as staging, filter fences, and berms. The current institutional framework for soil erosion control also provides disincentives to mitigate local erosion problems. 相似文献
86.
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
87.
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
88.
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
89.
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
90.
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