Environmental Science & Policy 5 (2002) 113–120 Fine tuning water quality regulations in agriculture to soil differences J. Bouma ∗ , B.J. van Alphen, J.J. Stoorvogel Laboratory of Soil Science and Geology, Wageningen University, P.O. Box 37, 6700 AA Wageningen, The Netherlands Abstract Groundwater quality has been defined in terms of threshold values for nitrate (50 mg l -1 ) and pesticides (0.1 gl -1 active substance). Variability in space and time, and cost and safety considerations have made it unattractive to verify water quality by repeated measurements. Proxy values have, therefore, been defined to characterise water quality. For nitrate, maximum allowable fertilisation rates have been specified and farmers have to apply the MINAS book-keeping system to keep track of their N-flows. For pesticides, listing of allowed pesticides functions as another proxy quality measure. Field tests and simulations on a Dutch farm demonstrated that water quality assessment using these proxy values does not correspond with direct assessment based on measurements and a comparison with the threshold values, which represent the true standard. A second problem is the generic character of the proxy methods, which do not reflect quite different nitrate and pesticide dynamics in different types of soil. These problems make the proxy approach quite problematic. We, therefore, propose the systematic introduction of information technology to be used for deriving soil-specific management practices that do not lead to an increase of the thresholds. Existing techniques for precision agriculture can be used, and the current registration of all parcels in The Netherlands in a geographical information system, including occurrence of different soil types, will be quite helpful. Such an information system on internet will allow better control than the current generic proxy systems and is likely to be quite motivating to farmers. © 2002 Published by Elsevier Science Ltd. Keywords: Groundwater quality; Environmental regulations; Soil quality; Environmental control systems 1. Introduction As long as food production was a major policy objective in post-war Europe, little attention was paid to the environ- mental side effects of agricultural production. Once food production started to exceed food consumption in the sev- enties of the twentieth century, the environmental impact of agricultural practices became a growing concern to groups of environmentally conscious citizens and politicians. En- vironmental protection laws were introduced, but their implementation proved to be slow, painful and difficult. Though farmers in western Europe currently constitute less than 5% of the population and their contribution to the gross national product is less than 5%, they still carry considerable political clout. This is partly due to the fact that their activities determine the state of the land in rural areas. Even in a densely populated country as The Netherlands, over 70% of the land is still used for agricultural production. Be that as it may, the question remains acute as to why the change to sustainable, economically viable farming systems is so difficult. ∗ Corresponding author. Tel.: +31-703-564-605; fax: +31-703-562-695. E-mail address: johan.bouma@bur.slm.wau.nl (J. Bouma). The role of research in this overall process deserves spe- cial attention, as research should be in a prime position to provide the keys to innovative development. So far, agricultural research has played a key role in: (i) providing basic data for environmental laws and regu- lations, (ii) developing policy tools for implementation of environmental regulations, and (iii) developing innovative sustainable farming systems. This paper intends to analyse the role of research in the three above areas, and provides examples of how research can contribute to a successful implementation of environmental legislation. Attention fo- cuses on the use of nitrogen fertilisers and pesticides, which currently receive ample attention in EU countries. Presented examples are based on research at a modern arable farm on prime agricultural land in The Netherlands. 2. The role of agricultural research 2.1. Basic data for environmental laws and regulations EU directives increasingly determine the threshold con- centrations for nitrogen and pesticides in soil and ground- water, that are to be implemented at the national level. Threshold values reflect concentrations that are not harmful 1462-9011/02/$ – see front matter © 2002 Published by Elsevier Science Ltd. PII:S1462-9011(02)00030-8