A RAPID CHEMICAL METHOD FOR ESTIMATING POTENTIALLY MINERALIZABLE AND PARTICULATE ORGANIC NITROGEN IN MOLLISOLS

MARTINEZ JUAN MANUEL; GALANTINI J.A

COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS

TAYLOR & FRANCIS INC

Lugar: Londres; Año: 2017 vol. 48 p. 113 - 123

0010-3624

The objective of this study was to obtain an indicator of labile nitrogen (N) through a cost- and time- saving procedure by evaluating the relationships among potentially mineralizable N (N0), particulate organic matter N (POM-N) and soil organic N extracted through partial soil digestion with different concentrations of sulphuric acid (H2SO4). Soil sampling (0-20 cm) was from nine fields under no-tillage. The N0 and POM-N were determined by long-term aerobic incubation and soil physical fractionation, respectively. A simple chemical method was developed by soil digestion at 100°C for 4h with different concentrations of H2SO4 (0.1, 0.5, 1, 6, 12 and 24 mol L-1). All acid concentrations showed significant relationships with N0 as POM-N, however, the best prediction was resulted for 0.5 mol L-1 (R2=0.90-0.94, respectively), thus using this methodology as soil labile N indicator. This method would optimize N0 and POM-N estimation in short term and at a low cost.