Plant nutrient supply and movement. Report of a panel

Despite the emphasis given by the Agency to the more practical field experimentation in agriculture like soil fertility and fertilizer utilization, it is obvious that any long-term programme of soil fertility research must also take into account the fundamentals of plant nutrient supply and movement. Thus a large gap exists between the present methods used for predicting the response of a crop to fertilizer on any given soil and fundamental knowledge in soil physics, chemistry and biology. Only when precise determinations can be made of the quantity of ions in the soil solution, the adsorption complex, and the rate at which the exchange processes occur, will it be possible to develop a scientific basis for the evaluation of the nutrient status of soils and to make efficient fertilizer recommendations. Study of these processes, and others, such as ion movement as affected by water flow and diffusion phenomena, have been carried out on a very limited scale by individual scientists in widely separated institutes. Comparative lack of progress in this field is, at least in part, due to the absence of co-ordinated planning and exchange of information among scientists working on these problems, and it is for this reason that this meeting has been organized by the Agency. From the research point of view a co-ordinated research contract programme on plant nutrient supply and movement has already been initiated and at present there are six contractors. An essential feature of the programme is co-ordination, and this Panel partly represents the second planning meeting of these contractors. The discussions will, however, have wider scope, as other acknowledged specialists in the subject are participating in this Panel