Effect of land use and topography on soil properties and agronomic productivity on calcareous soils of a semiarid region, Iran

摘要

In this research, the effects of land use and slope position on soil properties and its agronomic productivity were studied in a greenhouse experiment. The study also covered the effects of water stress, fertilizer treatment and their interactions. Eight soil samples were collected from four slope positions along hill slopes from two adjacent land use types of rangeland and dry farmland in a semiarid region of Iran. Soil samples were analyzed for their physical and chemical properties and yield and yield components of wheat were measured as indices of soil agronomic productivity in a replicated pot experiment. Soils of the dry farmland showed higher fertility and better quality than the soils from the adjacent degraded rangeland, especially at the upper slope positions. The results indicated that yield components of wheat were all higher for the dry farming land compared to the degraded rangeland, and at the bottom of slopes compared to the top. The effect of land use and slope position on agronomic productivity of soil was influenced by water supply. The actual impact on soil productivity of soil degradation, induced by land use and slope position, was overshadowed by the dominating effect of water stress. While both chemical fertilizer and fertilizer + manure treatments enhanced the agronomic productivity of all soils, their effects were much more pronounced on the degraded soils of the rangeland. Water stress reduced fertilizer efficiency on all the soils used in this study.