مطالعه ارتباط شاخص بيولوژيك قابليت جذب نيتروژن و برخي خصوصيات فيزيكي ، شيميايي و بيوشيميايي خاك در شماري از خاك هاي استان اصفهان

Association of biological index of nitrogen availability with some physical,chemical and biochemical properties of soils in Isfahan Province

This paper addresses the association between biological index of nitrogen availability (N,wa) and some physical, chemical and biochemical properties of soils. For this purpose, twenty soil samples were taken from different soil series of Isfahan province, central Iran. Particle size distribution, organic carbon (OC), Total nitrogen (TN), Cation exchange capacity (CEC), calcium carbonate equivalent (CCE), electrical conductivity of saturation extracts (ECe) and sodium adsorption ratio (SAR) were measured. Nava, L-asparagines and unease activities were also determined. Simple linear correlations revealed that Nava is positively correlated with OC and TN. ECe and SAR were negatively correlated with Nava. There were also positive associations between Nava and L-asparagines and urease activities. Multiple stepwise regressions revealed that 77 percent of Nava variation was only due to OC. It was concluded that the content of soil organic carbon plays a key role in bioavailability of nitrogen to soil organisms.