Tentative integration of new trends and methods in the study of soil/plant relationships

The planning meeting held at the IAEA in Vienna in 1964 under the co-ordinated research programme of 'Plant Nutrient Supply and Movement in Soil Systems' gave the impulse for a joint Scandinavian research programme to co-ordinate research efforts and apply modern techniques in questions relevant to soil/plant relationships. The countries involved work through specialized committees of the N.J.F. (Nordiske Jordbrugsforskeres Forening). These committees consist of three to five scientists from each country and they represent scientific institutions or laboratories. Basically the joint efforts would be those of applying modern ideas and techniques to a limited number of representative Scandinavian soils to gain more information on the availability of soil nutrients than that obtained through conventional soil testing or fertilization experiments. In this context, and with regard to phosphorus, the assessment of P-potentials, E-values, P-adsorption isotherms or diffusion patterns could be mentioned. Thermodynamic as well as kinetic approaches would be investigated in the over-all study of the mechanism by which soil-P is transported from the solid phases and through the soil solution to the root surfaces. Thus isotopic exchange might tell us the rate at which various solid soil-P fractions are dissolved, and the diffusion experiments would elucidate the rates at which dissolved phosphorus migrates through the soil solution as, e.g. a function of the water content. Parallel to this work, fertilization experiments might complete the picture. Yield curves should be established under standardized conditions, and by using labelled fertilizers we would obtain additional information on soil-P availability or capacity parameters. Soil-solution concentrations should be evaluated through activation analysis