Significance of the soil in environmental quality improvement--a review

The broad outlines of plant and animal ecology are indicated and ecosystems are defined. The impact of agriculture and industry on these systems is indicated. The major forces bringing about instability of the soil are pointed out. Wind erosion, water erosion, nutrient and oxygen balances are described in principle. Intensification and specialization of agriculture are described in some detail. These intensive practices are compared to the older “normal” agriculture. Hence, the courses of the modern agricultural problems in environmental pollution and waste management are indicated. The magnitude of the pesticide problem is defined and the need for regulation is emphasized. Special consideration is given to chlorinated hydrocarbons and mercury compounds. The process of eutrophication is defined and is described as a natural process. Sources of artificial enrichment of the water are described as well as city and rural waste water.The remedial measures that need to be taken to maintain and/or improve the environment are discussed. Systems of handling animal wastes are described in some detail. Dry, slurry, and wet systems are described in regard to management. The control of excessive fertilizer nutrients, pesticides, and agricultural chemicals including heavy metals is outlined in some detail. Animal manure management as a part of the soil fertility system is described. Nitrogen and phosphorus management is discussed in some detail. Utilization of city waste water and sewage treatment plant sludges are indicated. Solid waste disposal on the land as a means of environmental improvement is considered from the point of view of disposing of raw sewage, sewage sludge, and solid wastes generally. Fruit and vegetable processing wastes can be treated by a process of overland flow in order to bring about adequate oxidation of these wastes. Wastes from packing plants for animal processing are much stronger wastes and require more complex treatment than fruit and vegetable processing wastes. Oil-spills as a pollutant on land are described in more or less quantitative terms. Remedial measures are given.