Soil Degradation and Land Use

Abstract

The main aspects of environmental degradation that involve soil(erosion, soil compaction, soil crusting, deterioration of soilstructure, flooding, losses of organic matter, salinization, onsite andoffsite damages, etc.) result from human activities. Since conventionalagricultural production systems have resulted in excessive erosion andsoil degradation, change is needed that will control such ruin.Scientific results have clearly shown that agricultural managementsystems can play an important role in preventing soil degradationprovided that appropriate management practices are adopted. Long-termfield experiments in different types of soils have shown thatalternative tillage systems, such as minimum tillage, ripper subsoiling,etc., improve the soil structural quality. Continuous conventionaltillage causes a decrease in soil organic matter content associated witha decrease in aggregate stability, leading, as a consequence, to theformation of surface crusts, with an increase in runoff and erosionrisk.In hilly environments, land leveling and scraping are dangers to soil,causing its erosion.. After leveling, slopes being prepared for planting(particularly vineyards) are almost always characterized by the presenceof large amounts of jumbled earth materials accumulated by the scraper.In this vulnerable condition, a few summer storms can easily cause soillosses exceeding 500 Mg ha(-1)year(-1). Moreover, land leveling and theresulting soil loss cause drastic alteration of the landscape and lossof the cultural value of the soil.Subsoil compaction is strongly underevaluated, even though the presenceof a ploughpan at the lower limit of cultivation is largely widespreadin the alluvial soils of the plains cultivated by monoculture. It isresponsible for the frequent flooding of such plains when heavy rainsconcentrate in a short time (rainstorm), since the presence of thisploughpan strongly reduces drainage. Alternative tillage practices, likeripper subsoiling, are able to avoid the formation of this compactlayer.