Soil quality in organic farming

This project will address basic functions of soil that are of importance for organic farming. The aim is to improve the understanding of the managed soil ecosystem, and derive results that are applicable to the practical development of organic farming. The project includes two research topics, labelled A and B. Dissemination of results to consultants and farmers has a high priority.

Research topic A is concerned with the effects of subsoil compaction and loosening upon soil conditions and crop performance. It is the aim to elucidate how subsoiling of a compacted soil layer affects the growth of roots and shoots, and eventually crop yields as well as nutrient uptake. The effects of weed growth will be included in the studies too. It will be evaluated if re-compaction of loosened soil can be avoided by using on-land ploughing and by controlling axle loads and tyre pressures of vehicles trafficking the soil.

Research topic B is concerned with the topsoil tilth. A stable but yet friable soil is a major concern in order to obtain optimal growing conditions for plants. The soil tilth further determines the living conditions for soil biota. Earlier results indicated long-term influence of crop rotation and application of animal manure. Results also indicated a negative influence of tillage and traffic intensity. Further studies will be performed to increase knowledge of the importance of these basic management tools. The resulting tilth will be quantified in terms of structural strength/friability and characteristics of soil pores as a habitat for microorganisms.

Publications

Project title
I.7 Soil quality in organic farming: Effects of crop rotations, animal manure and soil compaction (ROMAPAC)

Project leader
Senior Scientist Per Schjønning
Danish Institute for Agricultural Sciences, Department of Crop Physiology and Soil Science
P.O. Box 50, DK-8830 Tjele
Phone: +45 89 99 17 66, Fax: +45 89 99 16 19
E-mail: Per.Schjonning@agrsci.dk

Project participants
Jørgen E. Olesen, Lars J. Munkholm, Susanne Elmholt and Torben S. Madsen, DIAS