Changes in Soil Organic Matter Under Different Tillage Systems and Crop Rotations in Three Semiarid Areas of Castilla and Leon

摘要

Soil organic matter (SOM) dynamics play a decisive role in soil quality, improving crop production and protecting environment (Bauer and Black, 1994), because it contributes to plant growth and development through its effect on the physical, chemicaland biological properties of soils (Tabatabai, 1996). Conservation tillage improves soil quality. Minimum or no tillage enhances soil structure, increasing organic mater content, present in top layer of the soil (Kay, 1995), but tillage effects on soil organic matter dynamics are complex and often variable. The degree of theses effects depends on soil type, crops, and tillage management systems. Crop rotations and the quality and quantity of crop residues on the soil surface can affect the increase of organic matter content (Wright and Hons, 2005). The objectives of this study are to evaluate the response of soil organic matter to different tillage systems and crop rotations in three semiarid areas of Castilla and Leon, Northern Spain.