Tese
Dinâmica do carbono e nitrogênio em argissolos com plantação de Eucalyptus sp.
Fecha
2013-03-04Registro en:
WINK, Charlote. Dynamics of carbon and nitrogen in alfisol/ultisol of Eucalyptus sp. plantations. 2013. 212 f. Tese (Doutorado em Recursos Florestais e Engenharia Florestal) - Universidade Federal de Santa Maria, Santa Maria, 2013.
Autor
Wink, Charlote
Institución
Resumen
Understanding the dynamics of carbon and nitrogen associated with the physical and chemical
properties of the soil are important for conscious planning the use and management of land under
cultivation of eucalyptus in order to act positively on the quality of the environment. The aim of this
study was to evaluate the dynamics of carbon and nitrogen in surface and depth in soils cultivated with
Eucalyptus sp., of different ages, in Central Depression and Southeast, Rio Grande do Sul. For this,
was evaluated: a) a) through nonparametric and multivariate analyzes, the ratio of total organic carbon
and total nitrogen with the physical and chemical properties at the surface and at depth in soils
cultivated with Eucalyptus sp., replacing the native grassland; b) the accuracy of the employment
Century 4.5 model in simulating the content of total organic carbon and total nitrogen in the 0.0-0.2 m
layer of soils cultivated with Eucalyptus sp.; c) the distribution of total organic carbon and of total
nitrogen in depth through the negative exponential mathematical model in soils cultivated with
Eucalyptus sp. The dynamics of total organic carbon and total nitrogen in Eucalyptus plantations,
replacing native grass, is related to the physical and chemical properties, and the use and soil
management, recognized by the test nonparametric univariate and multivariate analysis. In surface
soil that relationship is expressed by the variables already required at start of the simulation model of
the dynamics of soil organic matter (Century Model 4.5). Depth in the profile, this association is more
expressive with other properties, such as phosphorus, potassium, pHwater, calcium, magnesium, as
well as fine sand, the SMP index and macroporosity. One can also consider, in the background, the
coarse sand and clay. In a way this is important in the qualitative assessment of soil, since it makes
inferences about the degradation process and the productivity of these soils. The native grassland had
the highest similarities in the variations of soil properties in the surface layers, unlike Eucalyptus
plantations in that homogeneity is more pronounced in the deeper layers of the profile. The Century
Model 4.5 showed a good fit in the simulation of the stock of total organic carbon in the soil and can be
used in the simulation of organic matter dynamics in native grassland and Eucalyptus plantations in
the different districts. For the stocks of soil total nitrogen, even with the changes of parameters, the
Century Model 4.5 could not simulate with acceptable statistical accuracy when compared to the
observed data. The content of total organic carbon and total nitrogen in the soil depth of native
grassland and Eucalyptus plantations has negative exponential distribution, indicating that the model
was able to represent rated this dynamic. However, it should evaluate the quality of the method
employed in estimating the rate of decay of these contents, since differences were estimated in the
content of total organic carbon and nitrogen along the entire soil profile. Therefore, we suggest the
development of new long-term experiments in Eucalyptus plantations of different ages in different soil
depths in order to infer the temporal behavior of carbon and nitrogen in soil, based on the processes
of migration, degradation, stability and fractions of these elements.