SOIL EROSION AWARENESS AND USE OF CONSERVATION TILLAGE FOR WATER QUALITY CONTROL1

Water pollution through loss of topsoil from farmland continues to be a major problem, despite nearly 50 years of providing farmers technical and financial assistance for soil and water conservation. The technology for controlling erosion and water pollution is available, but farmers have been slow in implementing control practices. Past research has shown that farmers tend to be unaware of the seriousness of the erosion problem on their own operations. Using a random sample of farmers from central Iowa, the relationship is examined between awareness of a soil erosion problem and the use of conservation tillage. Results indicate that awareness of a soil erosion problem effects the use of conservation tillage, and that awareness can be enhanced by experiential educational strategies such as the development and implementation of a soil and water conservation plan.     

Measuring agricultural sustainability in terms of efficiency: the case of Dutch sugar beet growers

Sustainability embraces socio-economic and bio-ecological dimensions or attributes. This paper presents a conceptual framework for quantifying sustainability on the basis of efficiency theory commonly used in economics. The conceptual model is implemented using Data Envelopment Analysis (DEA). Sustainability is measured for a sample of Dutch sugar beet growers. The average technical efficiency was only 50%. A positive correlation was found between technical efficiency and sustainable efficiency. Differences in efficiency among farmers were persistent within and between years. We conclude that there is considerable scope for improving the sustainability of arable farming by better management.     

Rolex Calls for Entries to 11th Awards for Enterprise and Extends Deadlines for All Countries

Call for Papers

Rolex Calls for Entries to 11^th Awards for Enterprise and Extends Deadlines for All Countries     

Preparation and implementation of seven ecological compensation plans for Dutch highways

First-generation compensation plans (CPs) for Dutch highway projects have been evaluated with respect to implementation of the compensation principle (1993), which aims to counterbalance the adverse ecological impacts of large-scale development projects. Decision-making on the seven projects took place between 1993 and 1995. Specifically, we considered: (a) the processes employed to prepare and implement the compensation plans; (b) the methods used to identify, plan, and execute the compensation measures; and (c) the results yielded by these methods. We conclude that the CPs were prepared fairly uniformly, particularly in terms of the processes and methodologies used to derive compensation measures. Five of the seven CPs had become operational by 2001 and initial experience is now being gained on land acquisition and transfer of compensation sites to nature conservation trusts. Further progress of CPs is likely to be seriously hampered by growing demand for land for development in general and associated increases in real estate prices. Several problems are addressed and recommendations made with respect to: (a) developing a legal basis for the compensation principle; (b) the relationship with re-allotment projects; (c) estimation of compensation costs; (d) an annual bias of CP budgets to account for rising costs; (e) contingency measures; and (f) criteria for CP (ex-post) evaluation.     

Enantiomer ratios,patterns and levels of toxaphene congeners in human milk from Germany

High resolution gas chromatography (HRGC) coupled to quadrupole negative ion chemical ionization (NICI) mass spectrometry (MS) was used to investigate congener patterns, levels and enantiomer distribution of selected toxaphene congeners (#26, #41, #44, #50, #63, B7-1453) in human milk from Germany. #50 and #26 were the most abundant congeners. Furthermore, the identification of B7-1453, B8-1412, #41, #42, #44 and #63 was possible. Levels for the sum of #26, #41, #44 and #50 ranged from 7 to 24 microg kg(-1) milk fat and contributed between 2 and 9% to the total burden of investigated organochlorines such as selected compounds of the chlordane group, HCH, DDT and polychlorinated biphenyls (PCB). Capillaries coated with heptakis-(2,3,6-O-tert-butyldimethylsilyl)-beta-cyclodextrin (TBDMS-CD) or octakis-(2,3,6-tri-O-ethyl)-gamma-cyclodextrin (TEG-CD) were used for the enantioselective separations. Enantiomer ratios (ER) and enantiomer fractions (EF) of the abundant toxaphene congeners #26 and #50 as well as of B7-1453, #41 and #63 were determined. Greatest deviations from a racemic composition in individual human milk samples were found for #41 (1.54-2.37), #50 (1.37-1.72) and #63 (0.53-0.71) whereas ERs for #26 were close to 1. Compared to wildlife biota such as fish and raptors ER changes were more pronounced in human milk but comparable to human adipose tissue.     

Performance of poly(vinyl alcohol) gel columns on the ion chromatographic determination of perchlorate in fertilizers

Interest in possible sources of perchlorate (ClO4) that could lead to environmental release has been heightened since the Environmental Protection Agency placed this anion on its Contaminant Candidate List for drinking water. Although recent investigations have suggested that fertilizers are minor contributors to environmental perchlorate contamination overall, there is still interest in screening commercial products for possible contamination and quantitating perchlorate when it is found. Ion chromatography (IC) has been used for this application owing to its speed, low detection limits, widespread availability, and moderate ruggedness relative to other techniques. However, fertilizer matrixes complicate the IC analysis relative to potable water matrixes. In this study, the performance of poly(vinyl alcohol) gel resin IC columns (100 mm and 150 mm) was evaluated for fertilizer matrixes using method EPA/600/R-01/026. The NaOH eluent included an organic salt, sodium 4-cyanophenoxide. Detection was by suppressed conductivity. A set of 55 different field samples representing 48 products and previously used by the EPA to assess occurrence of perchlorate in fertilizers (EPA/600/R-01/049) was reanalyzed on the 150 mm column. The 100 mm column was used to further investigate the positive hits. Both columns gave satisfactory performance in fertilizer matrixes, with spike recoveries (+/- 15%), assured reporting levels (0.5-225 microg g(-1) except for one at 1,000 microg g(-1)), accuracy (relative error < 30% always and most < 15%), and precision [injection-to-injection reproducibility < 3% relative standard deviation (RSD)] comparable to those reported in other studies. Performance did not vary substantially between column lengths. Lastly, the results of this investigation provided further evidence in support of the conclusions that had been reached previously by the EPA on the occurrence of perchlorate in fertilizers.