A Simple and Rapid Method to Evaluate Potentially Mineralizable Nitrogen in Sewage Sludge Amended Calcareous Soils

Abstract

Potentially mineralizable nitrogen (PMN) can be usually considered as labile nitrogen. Measurement of PMN is expensive and time consuming; therefore, a simpler and more rapid alternative may facilitate routine laboratory analysis. The objective of this study was to determine the relationship between PMN and biological index of nitrogen availability (BINA). The studied soil was previously treated with 0, 25, and 100 tons ha-1 of sewage sludge with 0, 1, 2 and 3 consecutive years of application. Soil samples were taken 6 months after the latest application. PMN was measured according to Stanford and Smith procedure (20 weeks of aerobic incubation with 2 weeks leaching intervals) and BINA measured as described by Bundy and Meisinger (7 days of anaerobic incubation at 40˚ C followed by extraction of NH4+). Results showed that PMN was significantly correlated with BINA (r = 0.938, P

Keywords

• Nitrogen Mineralization Potential
• Biological Index of Nitrogen Availability
• sewage sludge