Chemical Soil Degradation Research Articles

Proposed assessment of the vulnerability of European soils to pollution using a soter shell approach

AbstractAfter recent unanticipated occurrences of environmental pollution caused by the time‐delayed and sudden release of contaminants previously believed to be held firmly in soils, awareness has increased that the vulnerability of soils to chemical degradation needs to be assessed and mapped. Although some soils appear to be capable of receiving and holding chemical compounds while at the same time retaining their ecological functions, others are readily damaged. Procedures for identifying areas where vulnerable soils occur are presented, with special reference to the minimum soil data sets that would be required in a small scale study at the European level using geographical information systems. These data can readily be compiled, stored and processed with the relational database management system developed for SOTER, The 1:1 million world soil and terrain digital database project of the International Society of Soil Science, which is co‐ordinated by the International Soil Reference and Information Centre. the proposed initial soil vulnerability programme would essentially serve to increase awareness about areas prone to chemical soil degradation, and will form the basis for implementing soil pollution assessment programmes at larger scales (1:1 M to 1:250 000). the latter national or regional programmes would include the identification of the major sources of soil pollution, and measurement of the accumulated load and the rate of loading according to uniform and standardized procedures, providing the conceptual basis for developing process based models to assess where particular types of soil degradation are likely to occur.

Expert Evaluation System for Assessing Field Vulnerability to Agrochemical Compounds in Mediterranean Regions

An expert evaluation system (named ARENAL) has been developed using a knowledge-based approach that allows estimation of the relative vulnerability of soil and groundwater to diffuse agrochemical contamination. ARENAL interprets groundwater vulnerability at the field scale especially from nitrate and pesticide leaching. Soil properties and related agricultural land-features are combined with management system criteria for Mediterranean regions. The Automated Land Evaluation System (ALES) was used to acquire this computer-captured expert knowledge and allied data. The ARENAL expert system uses basic input data or "key" parameters from existing soil and land survey information. Such an evaluation approach can be the basis for estimation of the environmental impact of agricultural activities, with reference to chemical degradation of soil and water resources.

Land-use Changes and Resource Degradation in South–West Masailand, Tanzania

This study uses sequential aerial photography to identify environmental changes. The interpreted aerial photos constitute a data-bank of past and present land cover/uses.* Substantial changes have been observed in the areas of cultivation, woody cover, and bare ground.An increased 449.9% of the surveyed area has been cleared for cultivation during the last 30 years, while 77.2% of the former woodland has been destroyed during the same period, contributing to a 15.6% increase in grassland. Bare ground increased by 33.1%. Increased cultivation is caused by increase in the population of subsistence farmers and mechanization. Expansion of cultivation and overexploitation of woody resources (fuel-wood and building materials) are the causes of decline in the woody vegetation. As consumption of woody resources exceeds natural regeneration, woody cover is gradually replaced by grasslands.Diminution of the woody vegetation results in shortage of fuel-wood and building materials and consequent misery to the local people. Expansion of cultivation reduces grazing-land, leading to overstocking and overgrazing. Extensive cultivation, based on soil ‘mining’, subjects more and more land to physical and chemical soil degradation, leading in turn to decline in soil fertility and crop yields. Both overgrazing and extensive cultivation accelerate soil erosion in the area, reducing available cropland, while siltation and flooding cause serious damage to property and infrastructure.Lack of effective land-use planning, uncontrolled population growth, and introduction of the Tanzanian village agricultural production system in a semi-arid area, have contributed to the present deplorable state of affairs. In general, the area shows increasing environmental degradation and resource depletion, while very little conservation effort is being made to reverse the trend. These results indicate that a sustainable resource management plan is urgently needed for the area.