Net nitrogen mineralization in soils under six indigenous tree species, an abandoned pasture and a secondary forest in the atlantic lowlands of costa rica

Abstract

Nitrogen mineralization, nitrification potentials, pH, total N, C, extractable P and cations were measured in soils under 4-year-old, mono-specific stands of six fast-growing, native tree species, an abandoned pasture, and a 20-year-old secondary forest, as part of a study on the use of indigenous tree species for rehabilitation of soil fertility' on degraded pastures at the La Selva Biological Station in the Atlantic humid lowlands of Costa Rica. Soil net nitrification potential rates were higher under two N-fixing, leguminous species, Stryphnodendron microstachyum Poepp. et Endl. (1.1-1.9 mg kg -1 day -1) and Dalbergia tucurensis Donn. Smith (0.7-1.5 mg kg-lday-1), than under the non-N-fixing trees in the plantation, Vochysia guatemalesis Don. Sm., Vochysiaferruginea Mart, Dipteryx panamensis (Pittier) Record and Mell and Hyeronima alchorneoides Fr. Allemao (0.2-0.8 mg kg-1 day-1). Values under the N-fixing trees were comparable to those found in secondary forest. There were no statistically significant: differences in soil total N or in other nurtients between the species. Results of pH measurements done before and after incubation did not show any clear evidence of a pH drop attributable to nitrification.

Five native tree species and manioc under slash-and-mulch agroforestry in the eastern Amazon of Brazil: plant growth and soil responses

“…Response in soil-N to the presence of N 2 -fixers has been reported previously (Montagnini and Sancho 1994). Fertilization with P plus K also did not create consistent patterns in soil concentrations of these or other nutrients.…”

Integrated evaluation of soil fertility in Ginkgo (Ginkgo biloba L.) agroforestry systems in Jiangsu, China

“…The lower soil pH in G?M may be due to increased soil nitrification (Binkley and Sollins 1990). Szott et al (1991) and Montagnini and Sancho (1994) also reported that incorporation of N 2 -fixing trees, such as Dalbergia, in the production system often results in increased soil N mineralization and nitrification, which leads to lower soil pH. Therefore, these results suggest that these systems of G?M, G?R?S and G?W?S significantly improved the organic matter and pH, especially in the upper soil layer, which may help in sustaining soil productivity.…”

Conocimientos y prácticas ancestrales y tradicionales fortalecen la sustentabilidad de los sistemas hortícolas de la parroquia de San Joaquín

“…However, after the bioassay, NO − 3 -N was considerably increased and NH + 4 -N decreased, suggesting that nitrification had occurred, perhaps caused by some form of incubation process in the bioassay pots. N mineralization experiments with volcanic soils in Costa Rica (Montagnini and Sancho, 1994) also revealed enhanced nitrification in incubations.…”