Spatial variability of soil CO2 emission in a sugarcane area characterized by secondary information
Carregando...
Data
2013-06-01
Autores
Teixeira, Daniel de Bortoli [UNESP]
Bicalho, Elton da Silva [UNESP]
Panosso, Alan Rodrigo [UNESP]
Cerri, Carlos Eduardo Pellegrino
Pereira, Gener Tadeu [UNESP]
Scala Júnior, Newton La [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade de São Paulo (USP), Escola Superior de Agricultura Luiz de Queiroz (ESALQ)
Resumo
Soil CO2 emission (FCO2) is governed by the inherent properties of the soil, such as bulk density (BD). Mapping of FCO2 allows the evaluation and identification of areas with different accumulation potential of carbon. However, FCO2 mapping over larger areas is not feasible due to the period required for evaluation. This study aimed to assess the quality of FCO2 spatial estimates using values of BD as secondary information. FCO2 and BD were evaluated on a regular sampling grid of 60 m × 60 m comprising 141 points, which was established on a sugarcane area. Four scenarios were defined according to the proportion of the number of sampling points of FCO2 to those of BD. For these scenarios, 67 (F67), 87 (F87), 107 (F107) and 127 (F127) FCO2 sampling points were used in addition to 127 BD sampling points used as supplementary information. The use of additional information from the BD provided an increase in the accuracy of the estimates only in the F107, F67 and F87 scenarios, respectively. The F87 scenario, with the approximate ratio between the FCO2 and BD of 1.00:1.50, presented the best relative improvement in the quality of estimates, thereby indicating that the BD should be sampled at a density 1.5 time greater than that applied for the FCO2. This procedure avoided problems related to the high temporal variability associated with FCO2, which enabled the mapping of this variable to be elaborated in large areas.
Descrição
Palavras-chave
Geostatistics, cokriging, ordinary kriging, cross-variogram
Como citar
Scientia Agricola. São Paulo - Escola Superior de Agricultura Luiz de Queiroz, v. 70, n. 3, p. 195-203, 2013.