Agronomists and ecologists need each other and can learn from each other: agriculture cannot ignore ecological facts, neither can ecology study and conserve ecosystems without understanding contemporary agriculture. With this intention a symposium was organized on "the ecological implications of contemporary agriculture". Five major groups of problems were discussed, related to major elements of the system, each corresponding to a session of the symposium:

- the soil and its life;
- the plants, especially the unwanted ones;
- the fauna, with emphasis on the control of pests;
- the nutrient cycles and nutrient budgets (the driving force);
- the connecting elements in the rural landscape, related as they are with lotting out.

For each subject (session) two invited papers were presented in combination with a varying number of posters. All these papers were encompassed by the opening and closing lectures, which sketch the societal framework within which a more ecological approach of agriculture has to be worked out.

In this overview the different elements are rearranged and assessed according to four major groups of problems: lotting out, nutrient management, soil treatment, and weed and arthropod control. It is concluded with some comments on the possibilities to realize more ecological approaches in the framework of farming-practice and EC-politics.

H. Eijsackers and A. Quispel are the authors of Ecological Bulletins, Bulletin 39, Ecological Implications of Contemporary Agriculture: Proceedings of a Symposium held 7-12 September, 1986, at Wageningen, published by Wiley.