UNIVERSIDAD AUSTRAL DE CHILE - Ipef

8 SUMMARY
With the objective to evaluating options of nutritional management in Eucalyptus
nitens, at the canopy closure (45 months old) in a red clay soils (serie Crucero, X Region,
Chile), the yield (DAP, basal area and volume) of eleven fertilization treatments that
combined sources of phosphorous of different solubility and lime, were compared.
Whereas, in the treatment with more P application and in the control (unfertilized), the
basic wood density, biomass accumulation (leaves, live branches, dead branches, bark,
wood and roots), litter accumulation and the annual litterfall, were determined. In the
biomass components, in the litterfall and in the litter, the concentration and the quantity of
N, P, K Ca, Mg, Fe, Mn, Cu, Zn and B were determined. Likewise, in the fertilized and in
the control treatments, the concentration and nutrients content of soil exchangeable
fraction and soil reserve fraction, until the 30 cm of depth, were determined. In both
treatments, the nutritious balance and the Reservation Vegetation Index were
determined.
The biggest response in yield was detected in the treatment with soluble phosphorous
applied to the beginning of the plantation and the beginning of the second year of growth.
In turn, the drop response to the less soluble phosphorous would be attributed to the
magnitude of the dose, regarding the capacity of fixation of phosphorus of the soil. The
lime didn't produce effects in the yield. The wood basic density increased significantly for
effect of the fertilization. The above-ground biomass in the fertilized treatment (90,4 t ha -1 )
it was 55 % bigger than the control (58,1 t ha -1 ). The litterfall evidenced a fall maxim in
summer and minimum in winter. The nutrient levels in the soil exchange fraction went
similar to those evaluated to the beginning of the plantation. The sequence of nutrients
concentration was leaves > fine roots > bark > branches > coarse roots > wood, and in
the part of the tree, upper > middle > low that which pointed out the efficiency of E. nitens
to transfer nutrients toward more active tissues. Until forty five months old, E. nitens
accumulated in the above-ground biomass and litter of the fertilized treatment 30 % more
than Ca and Mg and 10% more than N, P and K regarding the control. The average
accumulated in both treatments was (kg ha -1 ): 485 N, 26 P, 300 K, 450 kg Ca and 38 Mg.
The nutritious balance and the Vegetation Reserve Index identified that the soil is
unstable in K, P and Ca contents, conversely, the soil is stable in the Mg content.
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