Abstract

DAMIANO, Francisco  and  MOSCHINI, Ricardo Carlos. Least limiting water range in argiudoll soils under eucalyptus dunnii maiden. Cienc. suelo [online]. 2011, vol.29, n.1, pp.1-11. ISSN 1850-2067.

The Least Limiting Water Range (LLWR) integrates water potential, aeration and mechanical resistance conditions that can be limiting to plant growth. The LLWR was often determined in field crops, but studies performed under tree plantations are scarce. In this study, soil LLWR was determined in young and mature Eucalyptus dunnii plantations using pedo-transfer functions. Frequency of soil moisture values falling outside the LLWR (p_out) was statistically evaluated using the PROC CATMOD model. LLWR increased from 0.009 cm³ cm^{-3 in silty clay Bt horizons to 0.207 cm3} cm^{-3 in silty loam C horizons. The p}_out was negatively related to LLWR (R² = 0.83***). The slope of the fitted model (b₁ = - 30.5475) was not altered by climatic conditions, but its intercept varied from dry (b_o = 5.0083) to wet (b_o = 3.5207) years. From this empirical-fundamental model, it can be concluded that LLWR is a suitable index to indicate the best soil physical conditions for the growth of eucalyptus plantations.

Keywords : Water retention curve; Soil resistance; Pedo-transfer functions; Logistic regression.

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