自从 1 2 0年前首次对草地进行开垦以来 ,加拿大半干旱地区大草原的土壤遭受了彻底退化。土壤侵蚀、土壤有机质损失、作物对营养物质的吸收和盐渍化的后果使土地退化。造成土壤退化的原因包括 :强烈的耕作、种植单一作物以及对夏季休耕地的过度利用。在萨斯喀彻温省西南部进行 The soil of the prairies in semi-arid Canada has undergone complete degradation since the grasslands were first reclaimed in a decade ago. Soil erosion, loss of soil organic matter, crop uptake of nutrients and salinization degrade the land. Reasons for soil degradation include intense farming, single cropping and overuse of summer fallows. In southwestern Saskatchewan