Soil Physical Properties and Moisture Content Affected by Site Preparation in the Afforestation of a Semiarid Rangeland

摘要

Revegetation of arid regions is primarily water-limited. To test the impact of several afforestation site preparation methods on the physical properties and the moisture content of the soil, a factorial experiment was conducted in a degraded semiarid rangeland of southeastern Spain. The land preparation treatments evaluated were terracing (mechanical or manual) and organic amendment (with or without urban solid refuse, USR). Terracing negatively affected some of the physical characteristics of the surface soil, such as the proportion of stable aggregates (21–33% decrease). Mechanical terracing increased soil water storage up to 40% more than manual terracing. The addition of USR counteracted many of the negative effects of terracing on soil physical properties and significantly increased soil moisture, particularly in the mechanical terraces (up to 40% increase compared with the nonamended treatment). The beneficial effects of the organic amendment on soil water content in the mechanical terraces persisted 4 yr after the single addition of the USR. The combination of mechanical terracing and USR addition significantly enhanced soil water availability, which is the most likely factor for the enhanced plant survival and growth seen in this study.