Zeolitized tuffs as pedogenic substrate for soil re-building. Early evolution of zeolite/organic matter proto-horizons

摘要

An investigation was undertaken aiming to evaluate the suitability of zeolitized tuffs as an anthropogeomorphic material for soil re-building in degraded and desertified areas. Four artificial soil proto-horizons were prepared utilizing fine limestone gravel or Neapolitan yellow tuff as inorganic components, and sewage sludge or pellet manure as organic parent materials. The proto-horizons evolution was followed by analyzing leachates periodically collected over 80 days. After 80 days, the body of proto-horizons was also analyzed. Our results showed that the release of C- and N-compounds in the leachates was strictly dependent on the nature of the parent organic material. The presence of Neapolitan yellow tuff in the proto-horizon bodies clearly favored an advantageous evolution and stabilization of parent organic matrices, in optimizing the carbon to nitrogen ratios by increasing the C/N values, and by protecting the organic matter against a disproportionate degradation. Our findings led to conclude that the zeolitized tuff is a promising material in pedotechnique strategies for soil reconstruction and fight against desertification; on the contrary, the organic matter appeared to be excessively demolished in the presence of limestone gravel.