Contamination of the soil environment mostly is identified with industry, especially mining and road transport. Unfortunately, also in the commercial horticulture, there are numerous problems concerning the contamination of soils and substrates. Sources of contamination can be fertilizers and waste materials polluted by heavy metals, particularly by cadmium. In the greenhouses where traditional methods of cultivation are used, the soil pollution due to the application of excessively high doses of fertilizers constitutes an environmental hazard. Much faster similar effect occurs in greenhouses where an open system of fertigation is used. In addition to mineral impurities, organic compounds emitted by the plant or that are formed during decomposition of organic matter are the problem. This phenomenon is called allelopathy. In practice, it concerns the monoculture and perennial crops and especially is observed in nurseries, orchards, plantations of berries and asparagus. For this reason, in the later section, the soil sickness, replantation problem and toxicity of mulches in green areas are also discussed.
Part of the book: Soil Contamination