Vegetational designs for insect-habitat management

Insect habitats in anthropocentric ecosystems consist of crop plants or forest trees and the coexisting non-crop vegetation. The manipulation of the spatial and temporal arrangement of these plant communities can trigger direct or indirect effects on insect pest populations and their associated natural enemy complexes. In this article habitat management is viewed as a technique to design plant associations that support populations of natural enemies or that exert deterrent effects on herbivorous insects.     

Organic Farming Benefits Local Plant Diversity in Vineyard Farms Located in Intensive Agricultural Landscapes

The majority of research on organic farming has considered arable and grassland farming systems in Central and Northern Europe, whilst only a few studies have been carried out in Mediterranean agro-systems, such as vineyards, despite their economic importance. The main aim of the study was to test whether organic farming enhances local plant species richness in both crop and non-crop areas of vineyard farms located in intensive conventional landscapes. Nine conventional and nine organic farms were selected in an intensively cultivated region (i.e. no gradient in landscape composition) in northern Italy. In each farm, vascular plants were sampled in one vineyard and in two non-crop linear habitats, grass strips and hedgerows, adjacent to vineyards and therefore potentially influenced by farming. We used linear mixed models to test the effect of farming, and species longevity (annual vs. perennial) separately for the three habitat types. In our intensive agricultural landscapes organic farming promoted local plant species richness in vineyard fields, and grassland strips while we found no effect for linear hedgerows. Differences in species richness were not associated to differences in species composition, indicating that similar plant communities were hosted in vineyard farms independently of the management type. This negative effect of conventional farming was probably due to the use of herbicides, while mechanical operations and mowing regime did not differ between organic and conventional farms. In grassland strips, and only marginally in vineyards, we found that the positive effect of organic farming was more pronounced for perennial than annual species.     

Conservation of biodiversity within Canadian agricultural landscapes: Integrating habitat for wildlife

Industrialized agriculture currently substitutes many of the ecological functions of soil micro-organisms, macroinvertebrates, wild plants, and vertebrate animals with high cost inputs of pesticides and fertilizers. Enhanced biological diversity potentially offers agricultural producers a means of reducing the cost of their production. Conservation of biodiversity in agricultural landscapes may be greatly enhanced by the adoption of certain crop management practices, such as reduced pesticide usage or measures to prevent soil erosion. Still, the vast monocultures comprising the crop area in many Canadian agricultural landscapes are often of limited conservation value, thus the inclusion of appropriate wildlife habitat in and around arable lands is a fundamental prerequisite for the integration of wild species within agricultural landscapes. This review of current literature considers the potential for non-crop areas within agricultural landscapes to be reservoirs of agronomically beneficial organisms including plants, invertebrates, and vertebrate species. Non-crop habitats adjacent to crop land have been identified as significant for the maintenance of plant species diversity, for the conservation of beneficial pollinating and predatory insects, and as essential habitat for birds. A key component for enhancement of biodiversity is the reintroduction of landscape heterogeneity by (1) protection and enhancement of key non-crop areas, (2) smaller fields and farms, and (3) a greater mixture of crops, through rotation, intercropping and regional diversification. The benefits of increased biodiversity within arable lands are reviewed for various species groups. In the Canadian context, any serious attempt to derive significant agronomic benefit from increased biodiversity will require considerable changes in the agricultural programs and policies which shape mainstream industrialized agriculture. The problems of crop depredation by vertebrate species, weed and insect competition, which still represent significant impediments to the creation and proper management of wildlife habitat, are also discussed.     

Ecological impacts of arable intensification in Europe

Although arable landscapes have a long history, environmental problems have accelerated in recent decades. The effects of these changes are usually externalized, being greater for society as a whole than for the farms on which they operate, and incentives to correct them are therefore largely lacking. Arable landscapes are valued by society beyond the farming community, but increased mechanization and farm size, simplification of crop rotations, and loss of non-crop features, have led to a reduction in landscape diversity. Low intensity arable systems have evolved a characteristic and diverse fauna and flora, but development of high input, simplified arable systems has been associated with a decline in biodiversity. Arable intensification has resulted in loss of non-crop habitats and simplification of plant and animal communities within crops, with consequent disruption to food chains and declines in many farmland species. Abandonment of arable management has also led to the replacement of such wildlife with more common and widespread species. Soils have deteriorated as a result of erosion, compaction, loss of organic matter and contamination with pesticides, and in some areas, heavy metals. Impacts on water are closely related to those on soils as nutrient and pesticide pollution of water results from surface runoff and subsurface flow, often associated with soil particles, which themselves have economic and ecological impacts. Nitrates and some pesticides also enter groundwater following leaching from arable land. Greatest impacts are associated with simplified, high input arable systems. Intensification of arable farming has been associated with pollution of air by pesticides, NO2 and CO2, while the loss of soil organic matter has reduced the system's capacity for carbon sequestration. International trade contributes to global climate change through long distance transport of arable inputs and products. The EU Rural Development Regulation (1257/99) provides an opportunity to implement measures for alleviating ecological impacts of arable management through a combination of cross-compliance and agri-environment schemes. To alleviate the problems described in this paper, such measures should take account of opportunities for public/private partnerships and should integrate social, cultural, economic and ecological objectives for multifunctional land use.     

Crop damage and livestock depredation by wildlife: a case study from Nanda Devi Biosphere Reserve,India

The success of conserving biological resources in any Biosphere Reserve or protected area depends on the extent of support and positive attitudes and perceptions of local people have towards such establishments. Ignoring the dependence of the local people for their subsistence needs on resources of such areas leads to conflicts between protected area managers and the local inhabitants. Crop yield losses and livestock depredation were serious problems observed in most buffer zone villages of Nanda Devi Biosphere Reserve. In the present study 10 villages situated in the buffer zone of Nanada Devi Biosphere Reserve (1612 km2 area) in Chamoli district of Uttaranchal, India were studied during 1996-97 using a questionnaire survey of each household (419 = households; 2253 = total population in 1991; 273 ha = cultivated area). Estimates of crop yield losses were made using paired plots technique in four representative villages for each crop species. The magnitude of crop yield losses varied significantly with the distance of agricultural field from forest boundary. The total crop yield losses were high for wheat and potato in all the villages. The spatial distribution of total crop yield losses in any village indicated that they were highest in the area near to forest and least in the area near to village for all crops. Losses from areas near to forest contributed to more than 50% of total losses for each crop in all villages. However, in Lata, Peng and Tolma villages, the losses are high for kidney bean and chemmi (local variety of kidney bean) which varied between 18.5% to 30% of total losses in those villages. Potato alone represents 43.6% of total crop yield loss due to wildlife in Dronagiri village in monetary terms. Among the crops, the monetary value of yield losses are least for amaranth and highest for kidney bean. The projected total value of crop yield losses due to wildlife damage for buffer zone villages located in Garhwal Himalaya is about Rs. 538,620 (US$ 15,389). Besides food grains, horticultural crops i.e. apple, also suffered maximum damage. Major wildlife agents responsible for crop damage were wild boar, bear, porcupine, monkey, musk deer and partridge (chokor). Monkey and wild boar alone accounted for about 50% to 60% of total crop damage in the study villages. Goat and sheep are the major livestock killed by leopard. The total value of livestock losses at prevailing market rates is about Rs. 1,024,520 (US$ 29,272) in the study villages. Due to existing conservation policies and laxity in implementation of preventive measures, the problems for local inhabitants are increasing. Potential solutions discussed emphasize the need to undertake suitable and appropriate protective measures to minimize the crop losses. Change in cropping and crop composition, particularly cultivation of medicinal plants (high value low volume crops), were also suggested. Besides, fair and quick disbursement of compensation for crop loss and livestock killing need to be adopted. Local people of the buffer zone area already have a negative attitude towards park/reserve establishment due to socio-political changes inducing major economic losses and this attitude may lead to clashes and confrontations if proper ameliorative measures are not taken immediately.     

Bioremediation of soils contaminated with explosives

The large-scale industrial production and processing of munitions such as 2,4,6-trinitrotoluene (TNT) over the past 100 years led to the disposal of wastes containing explosives and nitrated organic by-products into the environment. In the US, the Army alone has estimated that over 1.2 million tons of soil have been contaminated with explosives, and the impact of explosives contamination in other countries is of similar magnitude. In recent years, growing concern about the health and ecological threats posed by man-made chemicals have led to studies of the toxicology of explosives, which have identified toxic and mutagenic effects of the common military explosives and their transformation products (Bruns-Nagel et al., 1999a; Fuchs et al., 2001; Homma-Takeda et al., 2002; Honeycutt et al., 1996; Rosenblatt et al., 1991; Spanggord et al., 1982; Tan et al., 1992 and Won et al., 1976). Because the cleanup of areas contaminated by explosives is now mandated because of public health concerns, considerable effort has been invested in finding economical remediation technologies. Biological treatment processes are often considered, since these are usually the least expensive means of destroying organic pollution. This review examines the most important groups of chemicals that must be treated at sites contaminated by explosives processing, the chemical and biological transformations they undergo, and commercial processes developed to exploit these transformations for treatment of contaminated soil. We critically examine about 150 papers on the topic, including approximately 60 published within the past 5 years.     

Review of studies on environmental impacts of recreation and tourism in Australia

The paper provides a review of available information on the impact of recreation and tourism on environments, particularly on vegetation and soil, in Australia, with an emphasis on forests. Efforts have been made to compare the current research and development situation in Australia with some overseas countries such as the United States and the United Kingdom. While many documents reveal that Australia has been experiencing an increasingly high level of recreation and tourism use in its environments, only limited studies of environmental impacts of recreation and tourism have been published. Compared with other developed countries, particularly the United Kingdom and the United States, Australia lags behind in undertaking research in this area. The results of these limited studies and some observations indicate that the most common recreational and tourist activities (such as bush walking, camping, horse-riding) can, if not well managed, adversely affect the values of Australian natural and semi-natural resources. Overall, they can affect the vegetation and other recreational sites physically and biologically. Physical effects include track formation, soil loss and/or compaction and an increase in fire frequency. Littering and water pollution are also seen as impacts associated with bush walking and camping. Biological effects include causing damage to vegetation, increasing risk of myrtle wilt disease and the spread of the soil pathogen,Phytophthora cinnamomi, as well as assisting weed dispersal. Based on the information reviewed, the authors suggest the following areas as priorities for future research into the environmental impact of recreation and tourism in Australia: determine the type of natural features that attract recreation use; determine the quantitative relationship between the impact and the level of recreation and tourism use for different activities within major vegetation habitats; ascertain site carrying capacity or environment thresholds for major vegetation habitats and recreation activities; and determine the impacts of recreation and tourism for major regions and major vegetation habitats where there have been considerable nature-based recreation and tourism activities.1998 Academic Press     

Application of game theory for a groundwater conflict in Mexico

Exploitation of scarce water resources, particularly in areas of high demand, inevitably produces conflict among disparate stakeholders, each of whom may have their own set of priorities. In order to arrive at a socially acceptable compromise, the decision-makers should seek an optimal trade-off between conflicting objectives that reflect the priorities of the various stakeholders. In this study, game theory was applied to a multiobjective conflict problem for the Alto Rio Lerma Irrigation District, located in the state of Guanajuato in Mexico, where economic benefits from agricultural production should be balanced with associated negative environmental impacts. The short period of rainfall in this area, combined with high groundwater withdrawals from irrigation wells, has produced severe aquifer overdraft. In addition, current agricultural practices of applying high loads of fertilizers and pesticides have contaminated regions of the aquifer. The net economic benefit to this agricultural region in the short-term lies with increasing crop yields, which requires large pumping extractions for irrigation as well as high chemical loading. In the longer term, this can produce economic loss due to higher pumping costs (i.e., higher lift requirements), or even loss of the aquifer as a viable source of water. Negative environmental impacts include continued diminishment of groundwater quality, and declining groundwater levels in the basin, which can damage surface water systems that support environmental habitats. The two primary stakeholders or players, the farmers in the irrigation district and the community at large, must find an optimal balance between positive economic benefits and negative environmental impacts. In this paper, game theory was applied to find the optimal solution between the two conflicting objectives among 12 alternative groundwater extraction scenarios. Different attributes were used to quantify the benefits and costs of the two objectives, and, following generation of the Pareto frontier or trade-off curve, four conflict resolution methods were then applied.     

Wildlife and integrated pest management

A number of options are available to those professionals interested in pest management through an integrated approach. The components of this approach are manipulation of vegetation; manipulation of population structure, dynamics, and interaction; and manipulation of the values associated with animal and plant crop production. Each component has numerous methods, which when used alone or in combination, offer a nearly infinite number of alternatives to the successful use of pesticides.Dr. Giles has taught a course in integrated plant pest management at Virginia Tech since 1977. The course is largely taught using computers. Students make management decisions to control pest damage and the computer determines how right they were.     

Damage costs of nitrogen fertilizer in Europe and their internalization

This paper estimates the environmental impacts and damage costs (‘external costs’) of synthetic nitrogen fertilizer and discusses options for reducing these impacts, including their consequences for farmers and for producers of fertilizer. The damage costs of the fertilizer life cycle that could be estimated are large, about 0.3 [euro]/kg_N (compared to the current market price of about 0.5 [euro]/kg_N); much of that is due to global warming by N₂O and CO₂ emissions during fertilizer production and N₂O emissions from fertilized fields. Policy options for internalizing these costs are discussed, and the consequences of reduced fertilizer input on crop yield are explored. If the damage costs were internalized by a pollution tax or tradable permits that are auctioned by the government, the economic consequences would be heavy, with a large revenue loss for farmers. However, if it is internalized by tradable permits that are given out free, the revenue loss for farmers is small. The loss for fertilizer producers increases linearly with the amount of external cost that is internalized, by contrast to the loss for farmers which increases quadratically but is very small for a damage cost of 0.3 [euro]/kg_N. Expressed as a change in the fertilizer-dependent part of the farmers' revenue (crop yield × crop price – fertilizer used× fertilizer price), the decrease is less than 0.5% for most crops; the losses are larger only for crops with low [euro]/ha revenue. Averaged over wheat, barley, potatoes, sugar beet and rapeseed, the loss to farmers is about 0.1% in the UK and 0.4% in Sweden. The revenue loss for fertilizer producers is larger, about 8% in the UK and 14% in Sweden.     

A new apparatus to enhance the rate of gas hydrate formation: Application to capture of carbon dioxide

A new apparatus employing a modular, mechanically agitated gas-inducing crystallizer is used to demonstrate the capture of CO₂ via hydrate crystallization. The crystallizer enhances the contact of hydrate forming gases with water and thus the rate of hydrate crystallization increases. Flue gas (CO₂/N₂) and fuel gas (CO₂/H₂) mixtures were used to represent post- and precombustion capture. A comparison between the rates of hydrate formation in different crystallizers is presented by defining a metric called the normalized rate of hydrate formation. The gas uptake and the separation efficiency for the fuel and flue gas mixtures were found to be greater compared to the results obtained in a smaller scale stirred tank reactor (Kumar et al., 2009c, Linga et al., 2008). The gas uptake and CO₂ recovery for flue gas mixture in the presence of THF obtained in this work was higher than that reported in the literature with tetra-n-butyl ammonium bromide and tetra-n-butyl ammonium fluoride (Fan et al., 2009, Li et al., 2009). Although hydrate crystallization is able to capture CO₂, the power required for mechanical agitation was found to be very significant. If the hydrate process is to be used industrially then hydrate crystallization must be carried out without mechanical agitation.     

Community-based participatory research: Changing scientific practice from research on communities to research with and for communities

This paper examines community based participatory research from the viewpoint of the author, a doctoral student seeking to understand the concepts and framework of successful participatory research as a complement to traditional discipline driven research. Challenges and progress of CBPR within academia are examined, including acceptance, funding, training, and development of equal partnerships between university researchers and communities. Case studies (Latowsky, 2003; Ammerman et al., 2003; Stratford et al., 2003) focus on CBPR in different environmental justice communities, revealing the need to foster trust and communication in order to execute culturally competent and relevant research projects.     

Spray drift of pesticides arising from aerial application in cotton

This paper presents results from field studies carried out during the 1993-1998 Australian cotton (Gossypium hirsutum L.) seasons to monitor off-target droplet movement of endosulfan (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin 3-oxide) insecticide applied to a commercial cotton crop. Averaged over a wide range of conditions, off-target deposition 500 m downwind of the field boundary was approximately 2% of the field-applied rate with oil-based applications and 1% with water-based applications. Mean airborne drift values recorded 100 m downwind of a single flight line were a third as much with water-based application compared with oil-based application. Calculations using a Gaussian diffusion model and the U.S. Spray Drift Task Force AgDRIFT model produced downwind drift profiles that compared favorably with experimental data. Both models and data indicate that by adopting large droplet placement (LDP) application methods and incorporating crop buffer distances, spray drift can be effectively managed.     

Comment: Investor demand and spot commodity prices

Tilton et al. claim in their article “Investor demand and spot commodity prices” to show that “investor demand can be pushing up a commodity's price even when investor stocks are falling.” In the present comment, it is argued that in both the cases described by Tilton et al., investors are supplying the market, putting physical material into it, rather than adding to demand. Thus, the reasoning by Tilton et al. is not concerned with the phenomenon referred to in the traditional theory, where, in the absence of changes in demand and supply fundamentals, prices rise as a result of increased investor demand for futures contracts.     

The quandary of local people—Park relations in Nepal's Royal Chitwan National Park

This paper analyzes five major causes of park-people conflicts that have occurred in Nepal's Royal Chitwan National Park. The causes include illegal transactions of forest products from the park, livestock grazing in the park, illegal hunting and fishing, crop damage, and threats to human and animal life caused by wild animals from the park. The conflicts indicate a reciprocal relationship between the park and local people. They reflect the attitudes of local people and representatives of the park authority whose priorities and objectives largely diverge. The results show that people settled adjacent to the park are heavily dependent on its resources. Even in places where some, albeit few alternative sources exist, local people continue to trespass the park boundary as these sources are inadequate to ensure the fulfillment of local people's resource needs. Illegal transactions of resources continue throughout the year; however, they are less intense during summer due to flooding caused by the Rapti River, which forms the park boundary towards the northern section where this study is conducted. The frequency of local people's visits to the park is mainly determined by their age, distance between homesteads and park, and volume of crop loss caused by wild animals. Crop damage is the function of size of landholding, distance, and frequency of crop raid. Local people claim that they have no intention of letting their livestock graze in the park; however, the dense vegetation of the park attracts livestock grazing on riverbanks just outside the open park boundary. Many head of livestock are killed by carnivores of the park. Human casualties are mainly caused by sloth bear (Melursus ursinus), tiger (Panthera tigris), wild pig (Sug scrofa), and rhinoceros (Rhinoceros unicornis). There had been some earlier attempts to reconcile the conflicts by offering local people different kinds of compensations; however, these were unsuccessful measures. An integrated approach is essential if efforts to resolve the park-people conflicts are to succeed. The government is in the process of launching a project that aims to resolve the inherent problems with such an approach. Suggestions are made to incorporate some key elements, such as maintaining effective communication between various parties and the potential for wildlife conservation among local people.     

Weed manipulation for insect pest management in corn

Populations of insect pests and associated predaceous arthropods were sampled by direct observation and other relative methods in simple and diversified corn habitats at two sites in north Florida during 1978 and 1979. Through various cultural manipulations, characteristic weed communities were established selectively in alternate rows within corn plots.Fall armyworm (Spodoptera frugiperda J. E. Smith) incidence was consistently higher in the weed-free habitats than in the corn habitats containing natural weed complexes or selected weed associations. Corn earworm (Heliothis zea Boddie) damage was similar in all weed-free and weedy treatments, suggesting that this insect is not affected greatly by weed diversity. Only the diversification of corn with a strip of soybean significantly reduced corn earworm damage.In one site, distance between plots was reduced. Because predators moved freely between habitats, it was difficult to identify between-treatment differences in the composition of predator communities. In the other site, increased distances between plots minimized such migrations, resulting in greater population densities and diversity of common foliage insect predators in the weed-manipulated corn systems than in the weed-free plots. Trophic relationships in the weedy habitats were more complex than food webs in monocultures.Predator diversity (measured as mean number of species per area) and predator density was higher in com plots surrounded by mature, complex vegetation than at those surrounded by annual crops. This suggests that diverse adjacent areas to crops provide refuge for predators, thus acting as colonization sources.     

RIPARIAN LAND USES AND PRECIPITATION INFLUENCES ON STREAM BANK EROSION IN CENTRAL IOWA1

Human alterations to the Iowa landscape, such as elimination of native vegetation for row crop agriculture and grazing, channelization of streams, and tile and ditch drainage, have led to deeply incised channels with accelerated streambank erosion. The magnitude of streambank erosion and soil loss were compared along Bear Creek in central Iowa. The subreaches are bordered by differing land uses, including reestablished riparian forest buffers, row crop fields, and continuously grazed riparian pastures. Erosion pins were measured from June 1998 to July 2002 to estimate the magnitude of streambank erosion. Total streambank soil loss was estimated by using magnitude of bank erosion, soil bulk density, and severely eroded bank area. Significant seasonal and yearly differences in magnitude of bank erosion and total soil loss were partially attributed to differences in precipitation and associated discharges. Riparian forest buffers had significantly lower magnitude of streambank erosion and total soil loss than the other two riparian land uses. Establishment of riparian forest buffers along all of the nonbuffered subreaches would have reduced stream‐bank soil loss by an estimated 77 to 97 percent, significantly decreasing sediment in the stream, a major water quality problem in Iowa.     

Long-term effects of sustained beef feedlot manure application on soil nutrients, corn silage yield, and nutrient uptake

A field study was initiated in 1992 to investigate the long-term impacts of beef feedlot manure application (composted and uncomposted) on nutrient accumulation and movement in soil, corn silage yield, and nutrient uptake. Two application strategies were compared: providing the annual crop nitrogen (N) requirement (N-based rate) or crop phosphorus (P) removal (P-based rate), as well as a comparison to inorganic fertilizer. Additionally, effects of a winter cover crop were evaluated. Irrigated corn (Zea mays L.) was produced annually from 1993 through 2002. Average silage yield and crop nutrient removal were highest with N-based manure treatments, intermediate with P-based manure treatments, and least with inorganic N fertilizer. Use of a winter cover crop resulted in silage yield reductions in four of ten years, most likely due to soil moisture depletion in the spring by the cover crop. However, the cover crop did significantly reduce NO3-N accumulation in the shallow vadose zone, particularly in latter years of the study. The composted manure N-based treatment resulted in significantly greater soil profile NO3-N concentration and higher soil P concentration near the soil surface. The accounting procedure used to calculate N-based treatment application rates resulted in acceptable soil profile NO3-N concentrations over the short term. While repeated annual manure application to supply the total crop N requirement may be acceptable for this soil for several years, sustained application over many years carries the risk of unacceptable soil P concentrations.     

Farm management indicators and farm typologies as a basis for assessments in a changing policy environment

This paper focuses on the assessment of farm management indicators and argues that typologies are a necessary tool for comprehensive environmental assessments. In the paper Andersen et al., [(2004a). Farming and the Environment in the European Community--using agricultural statistics to provide farm management indicators. Paper presented at OECD Expert meeting, March 2004, New Zealand. < http:webdomino1.oecd.org/comnet/agr/farmind.nsf/viewHtml/index/$FILE/Anderson_et_al.PDF> (1st of February 2006).] presented at the OECD expert meeting on farm management indicators in New Zealand in March 2004, a set of farm management indicators was presented in the framework of a typology of grazing livestock farming systems in the EU-15 (includes all Member States of the European Union before 2004). The present paper presents new results on farm management indicators within the framework of an extended typology for all farming sectors. It presents an environmentally oriented extension to the EU typology of farms currently used for assessing the situation of farming within the European Union. The extended typology is tested in relation to emerging policy issues such as environmental sustainability and rural viability by analysing some of the farm management indicators suggested in Andersen et al., [(2004a). Farming and the Environment in the European Community--using agricultural statistics to provide farm management indicators. Paper presented at OECD Expert meeting, March 2004, New Zealand. (1st of February 2006).]. Finally, recommendations in relation to the next generation EU farm typology are given.     

A preliminary cost and engineering estimate for desalinating produced formation water associated with carbon dioxide capture and storage

The risk associated with storage of carbon dioxide in the subsurface can be reduced by removal of a comparable volume of existing brines (e.g. Buscheck et al., 2011). In order to avoid high costs for disposal, the brines should be processed into useful forms such as fresh and low-hardness water. We have carried out a cost analysis of treatment of typical subsurface saline waters found in sedimentary basins, compared with conventional seawater desalination. We have also accounted for some cost savings by utilization of potential well-head pressures at brine production wells, which may be present in some fields due to CO₂ injection, to drive desalination using reverse osmosis. Predicted desalination costs for brines having salinities equal to seawater are about half the cost of conventional seawater desalination when we assume the energy can be obtained from excess pressure at the well head. These costs range from 32 to 40¢ per m³ permeate produced. Without well-head energy recovery, the costs are from 60 to 80¢ per m³ permeate. These costs do not include the cost of any brine production or brine reinjection wells, or pipelines to the well field, or other site-dependent factors.