Soil matric potential effects on gross rates of nitrogen mineralization in an orthic ferralsol from Kenya

• Published in: Soil biology & biochemistry Vol. 25; no. 10; pp. 1409 - 1413
• Main Authors: Pilbeam, C.J., Mahapatra, B.S., Wood, M.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.10.1993; New York, NY Elsevier Science
• Subjects: Agronomy. Soil science and plant productions; ammonification; biogeochemical cycles; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; Fundamental and applied biological sciences. Psychology; nitrification; nitrogen; nutrient availability; Organic matter; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Soil science; soil water content; soil water regimes; Kenya; Africa; Isotope labelling; Tropical zone; Nitrogen; Matric potential; Soils; Nitrogen cycle; Dry season; Ammonification; Moisture content; Mineralization; Humidity; Nitrification; Rainy season
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/0038-0717(93)90055-G

Gross rates of ammonification were measured over 9 days by 15N isotope dilution techniques allied to a mathematical model in an Orthic Ferralsol from Kenya. Rates of mineralization in soils conditioned for 24 days at different constant gravimetric moisture contents increased from 0.08 μg −1 Ng −1 d −1 for both ammonification and nitrification at −5.91 MPa to 2.12μg Ng −1d −1 ammonification at −0.063 MPa. In soil which had been conditioned constantly at −5.91 MPa then wetted to −0.42 MPa, gross mineralization rates were immediately stimulated. Wetting a soil conditioned at −0.42 MPa had no effect on rates of gross mineralization over 9 days.