Effects of Land Use Change and Seasonality of Precipitation on Soil Nitrogen in a Dry Tropical Forest Area in the Western Llanos of VenezuelaReport as inadecuate




Effects of Land Use Change and Seasonality of Precipitation on Soil Nitrogen in a Dry Tropical Forest Area in the Western Llanos of Venezuela - Download this document for free, or read online. Document in PDF available to download.

The Scientific World Journal - Volume 2014 2014, Article ID 514204, 11 pages -

Research Article

Universidad Nacional Experimental Sur del Lago “Jesús María Semprum” UNESUR, Programa Ingeniería de la Producción Agropecuaria, Laboratorio de Suelos, Santa Bárbara, Municipio Colón 5148, Estado Zulia, Venezuela

Instituto Venezolano de Investigaciones Científicas IVIC, Centro de Ecología, Laboratorio de Ecología de Suelos, Km 11, Carretera Panamericana, Altos de Pipe 1020, Estado Miranda, Venezuela

Received 16 July 2014; Revised 4 September 2014; Accepted 1 October 2014; Published 31 December 2014

Academic Editor: Antonio Paz González

Copyright © 2014 Ana Francisca González-Pedraza and Nelda Dezzeo. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We evaluated changes of different soil nitrogen forms total N, available ammonium and nitrate, total N in microbial biomass, and soil N mineralization after conversion of semideciduous dry tropical forest in 5- and 18-year-old pastures YP and OP, resp. in the western Llanos of Venezuela. This evaluation was made at early rainy season, at end rainy season, and during dry season. With few exceptions, no significant differences were detected in the total N in the three study sites. Compared to forest soils, YP showed ammonium losses from 4.2 to 62.9% and nitrate losses from 20.0 to 77.8%, depending on the season of the year. In OP, the ammonium content increased from 50.0 to 69.0% at the end of the rainy season and decreased during the dry season between 25.0 and 55.5%, whereas the nitrate content increased significantly at early rainy season. The net mineralization and the potentially mineralizable N were significantly higher in OP than in forest and YP, which would indicate a better quality of the substrate in OP for mineralization. The mineralization rate constant was higher in YP than in forest and OP. This could be associated with a reduced capacity of these soils to preserve the available nitrogen.





Author: Ana Francisca González-Pedraza and Nelda Dezzeo

Source: https://www.hindawi.com/



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