نوع مقاله : مقاله پژوهشی
نویسندگان
1 استادیار خاکشناسی دانشگاه شیراز، دانشکده کشاورزی و منابع طبیعی داراب
2 دانشیار خاکشناسی دانشکده کشاورزی دانشگاه شیراز
3 استاد خاکشناسی دانشکده کشاورزی دانشگاه شیراز
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Copper (Cu) deficiency is common in calcareous soils of Fars province. Organic matter (OM) and moisture regime (MR) are among the most influential factors affecting Cu behavior in soils. The present experiment was a 2×2×20 factorial arranged in a completely randomized design with two wheat straw application rates (0 and 2%), two MR levels (20% moisture by weight and waterlogging) and 20 calcareous soils. The soils were incubated under laboratory conditions and chemical forms of Cu were determined after 60 days of incubation. Results showed that the amounts of exchangeable and water soluble Cu were not detectable. Specifically adsorbed Cu was higher in unsaturated soils than saturated treatments. Application of OM under waterlogged condition had no significant effect on the amounts of Cu bounds to carbonate, Mn-oxides, amorphous, and crystalline Fe oxides. Waterlogging increased the carbonate and amorphous Fe oxides Cu but decreased that of crystalline Fe oxides. Organic Cu was more in waterlogged soils compared to unsaturated soils. Addition of OM increased organic Cu but decreased residual Cu under waterlogging. Also, negative correlations were obtained between these two forms under waterlogging. Application of OM to waterlogged soils increased the specifically adsorbed Cu and decreased that of residual. This demonstrates that OM treatment before planting, might be considered as a useful practice for paddy fields. Due to the fact that addition of such a straw rate to soils under field condition is not economically feasible, therefore, evaluation of lower rates of OM is highly recommended.
کلیدواژهها [English]