Soil mechanical penetration resistance exerts a strong influence on plant development since the root growth as well as crop yield are inversely related to this variable. On the other hand, soil organic matter and pH are also relevant for plant development, for being directly linked to soil nutrient availability. In the 2005/2006 growing season, the following dendrometric parameters of Eucalyptus camaldulensis were analyzed: (a) wood volume (WV), (b) perimeter at breast height (PBH) and c) plant height (PH), and the soil attributes: a) mechanical penetration resistance (MP), b) gravimetric moisture (GR), (c) organic matters (OM) and (d) and pH in a Dystrophic Red Latosol of the Cerrado (savanna-like vegetation). The purpose was to study the linear and spatial correlations among these variables, and to obtain soil quality indices for eucalyptus. A geostatistical grid was installed to collect soil and plant data, with 122 sample points, in an area of 1.98 ha. The variability of the plant data was medium and high, while the variability of the soil data was low, medium and high. The attributes WV, PB, PH, MP, GR, OM, and pH did not change randomly. Rather, they followed well-defined spatial patterns, with ranges between 17 and 169 m. The simple linear correlations among the attributes (plant and soil) were low, however significant for the attribute pairs WV vs MP1, WV vs MP5, WV vs OM2 and WV vs pH1. From the spatial correlation viewpoint WV varied significantly, inversely proportional to MP5 and pH1. The soil pH, sampled from the 0-0.15 m layer (pH1), turned out to be the best quality indicator of the studied soil toward estimating eucalyptus wood yield.
mechanical penetration resistance; soil physical properties; soil chemical properties; soil quality indicators; Eucalyptus camaldulensis
