Selected activities in the Environmental Science and Technology Department during 1991 are presented. The research approach in the department is predominantly experimental. The research topics emphasized are introduced and reviewed in chapters one to seven: 1. Introduction, 2. The Atmosphere, 3. Plant Genetics and Resistance Biology, 4. Plant Nutrition, 5. Geochemistry, 6. Ecology, 7. Other activities. The Department`s contribution to national and international collaborative research programmes is presented together with information about large facilities managed and used by the department. Information about the department`s education and training activities are included in the annual report along with lists of publications, publications in press, lectures and poster presentations. Further, names of the scientific and technical staff members, Ph.D. students and visiting scientists are listed. (au) (23 ills., 58 refs.).