Restoring the productivity of marginal soils with organic amendments

Abstract

The mining of sand and gravel deposits and excavation oftopsoil in urban areas have left extensive tracts of exposed subsoils that do not support plant growth because of adverse soil chemical and physical properties. Such degraded and marginal soils, or spoils, are infertile, low in organic matter, often acidic, and subject to severe erosion and surface runoff Many of these lands are owned by small and part-time farmers who wish to restore their aesthetic value and agricultural productivity. Research has shown that with liming and the proper use of organic amendments such as animal manures and sewage sludge compost, these lands can be restored to a high level of productivity in as little as three years. The methods and techniques for improving the productivity of marginal soils described in this paper can be of considerable benefit to some farmers in developed and developing countries where there is no other choice but to farm marginal soils because of the lack of highly productive agricultural lands. With increased efforts to restore the productivity of degraded and marginal soils through the use of organic amendments, conservation tillage, and crop rotations, future research should address the effect of best management practices on crop yields, the nutritional quality of crops, and the bioavailability of plant nutrients to both animals and humans.