Variabilidade espacial de atributos químicos de um Latosso vermelho-amarelo e de produção de laranja Var. folha murcha no sul do estado do Espírito Santo / Spatial variability of chemical attributes oxisol and production of a Folha Murcha orange orchard in South of the Espírito Santo

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

26/06/2008

RESUMO

The orange is among the agricultural crops of greatest importance to the Brazilian economy, bringing guarantee of income and subsistence, especially for small and medium rural producers. In view of the current state of nutritional management of culture adopted in the region, coupled to the low natural fertility of the soil and high nutritional exigency of the culture, there is need of new technologies to be aggregated to the production system and made available to the productive sector. This work had as objective the use of the geostatistics for the study of spatial variability of the chemical attributes of soil and the production of a Folha Murcha orange orchard. The work was conducted in an experimental area located in commercial farming in the district of Rive, municipality of Alegre-ES. The experimental area formed by a regular grid of approximately 0.2 hectares, totaling 80 points sample, spacialized 5 x 5 m. For each sampling point, four simple samples of soil in each depths (0-0,20 m and 0,20-0,40 m) were removed and homogenized resulting in a composite sample for determining of the chemical attributes of soil: pH in water, P, K, Ca, Mg, Al, H + Al, SB, T, V, t, m and total organic carbon. The production of the orchard was evaluated by the total number of fruit per plant, total mass of fruit per plant and fruit weight. For the evaluations, initially, was made an exploratory descriptive analysis without to consider the spatial position of the samples, making the identification of measures of position, dispersion and outliers and, subsequently, an exploratory spatial analysis, considering the position of the samples in the area to identify possible trends. The analysis of the spatial variability of the attributes studied was determined by standardized semivariograms. Through the adjustment of theoretical semivariograms values were estimated for the chemical attributes of soil studied in positions not sampled in the field, using the method of interpolation by ordinary kriging for making the maps that allowed the distinction of regions with lower and higher variability of attributes evaluated. With the results is possible to conclude that: using techniques of geostatistics is possible to identify different areas of management of the soil fertility; all attributes present structure of spatial dependence with degree of dependence varying between strong and moderate, with the most of the attributes adjusting to the spherical model, with exception of the chemical attribute of soil pH (0-0,20 m) and the attribute of production (fruit weight) that show pure nugget effect; the chemical attributes of soil Mg (0-0,20 m ) and SB (0-0,20 m) show linear model without landing; it is possible by the ordinary kriging, estimate the values of the chemical attributes of soil and of the production that present spatial dependence in the two depths; and the total organic carbon shows the same spatial distribution pattern with adjust in the spherical model and with the same ranges in the two depths

ASSUNTO(S)

manejo e conservacao do solo citrus sinensis l. osbeck fertilidade do solo krigagem geoestatística soil fertility kriging geostatistics

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