Abstract

Of the known essential micro nutrients in higher plants the majority (Fe, Mn, Zn, Cu, B, Co and Ni) become less available to plants with liming and increasing soil pH. Organic fertilizers like cattle manure, green mulch and green manuring crops are reported to increase availability of several trace elements, often by creating reducing soil conditions and decreasing soil pH. However, the effect is often more pronounced at relatively low soil pH, below 6.0. At higher soil pH, acidifying mineral fertilizers usually are more effective. A literature review, together with results from field experiments in northern Sweden, indicate that a relatively low soil pH (about 5.5) is favourable when organic fertilizers are used and that harmful effects of very low soil pH (<5.0), are ameliorated by organic materials but aggravated by mineral fertilizers. In organic growing a reconsideration of traditional pH and lime recommendations which are historically connected to the use of mineral fertilizers is needed

Published in

Publisher: Det Norske Videnskaps-Akademi

Conference

Geomedical Aspects of Organic Farming. Proceedings of a Symposium held at the Norwegian Acdemy of Science and Letters

SLU Authors

• Magnusson, Margareta

  • Department of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Food Science
Horticulture


Permanent link to this page (URI)

https://res.slu.se/id/publ/3980