Contribution of nitrogen mineralization indices, labile organic matter and soil properties in predicting nitrogen mineralization

MARTÍNEZ, JUAN MANUEL; GALANTINI, JUAN ALBERTO; DUVAL, MATIAS EZEQUIEL

Journal of Soil Science and Plant Nutrition

Sociedad Chilena de la Ciencia del Suelo

Año: 2018 vol. 18 p. 73 - 89

0718-9516

The objectives of this study were i) to measure the nitrogen (N) mineralization potential; ii) to evaluate N mineralization indices and labile soil organic matter (SOM) fractions, and iii) to analyze their interrelationship with soil properties for predicting the potential N mineralization in Mollisols under no-tillage of the Argentine Pampas. Potential N mineralization pool was determined by aerobic incubation of soil samples from 0-20 cm depth at 25°C for six drying and rewetting cycles over 21-24 weeks. The data were fitted to a first-order exponential equation to determine the potentially mineralizable N at a variable (N0) and at a fixed constant rate (N0kf). Several N mineralization indices, labile organic fractions and soil properties were determined. A broad range of values were found for N0 (29.9-220.7 mg kg-1) and N0kf (26.9-172.4 mg kg-1). A close relationship (P