Effects of Agricultural Practices on the Physical, Chemical and Biological Properties of Soils: Part III—Chemical Degradation of Soil as the Result of the Use of Mineral Fertilizers and Pesticides: Aspects of Soil Quality Evaluation

Summary

Agricultural crop production is dependent on application of compounds to soil. The purpose may be improvement of the nutrient supply as with fertilization practices, or crop protection and disease control as in the case of pesticide use. Such additions may induce chemical degradation of soil because of compound presence at undesirable level. This may specifically exert itself in long-term effects as the result of compound accumulation. For mineral fertilizers this is amongst other things caused by imbalance between supply and plant uptake or requirements, resulting for example from non-optimal relative presence of elements in the fertilizers. For pesticides the compound degradability plays a major role, in addition to its toxicity and mobility in soil A prerequisite for the establishment of rules and measures for soil protection is a means for soil quality evaluation. With respect to contamination or pollution of soil, behaviour of the compound of interest in the soil system then takes a key position. This behaviour is governed by a large number of variables. As most important in this respect the buffering capacity of soil, compound speciation, heterogeneity of soil systems and bioavailability of compounds are elaborated somewhat further. According to the author’s opinion these present at the same time the problem areas which deserve major attention in research programs directed towards the scientific foundation of soil protection.