Abstract

GARCIA, M. de los Á.  and  DE LA PENA, C.. Response to Autumn Fertilization by Eucalyptus plantations in Entre Rios. Quebracho (Santiago del Estero) [online]. 2013, vol.21, n.1, pp.16-25. ISSN 1851-3026.

In the study area, fertilization of eucalypt plantations is adopted to promote early site occupation, significantly increasing initial growth and obtaining the highest growths when N, P and in less proportion K fertilizers are used. On the other hand, frost resistance can be affected by nutrient level, although N, P and K fertilization effects on some forest species cold hardiness are confuse. In this region the repeated frosts that occurred the past years encouraged foresters to implement potassium fertilization during autumn, to prevent young plantations from severe frost damage. Unfortunately, those tests have not been documented nor evaluated; consequently, there are no regional records about fertilizers, doses or effects on eucalypts behavior related to low temperatures. To evaluate autumn fertilization with potassium and nitrogen effects on frost hardiness and growth of Eucalyptus grandis, two trials were set with 9 fertilization treatments. Frost damage and growth were measured, and ANAVA, Fisher's LSD and contingency tables were applied. In 2010 no visible frost damage was registered but height was significantly higher in plots with Nitrofull 60 g/tree than plants from KCl 34 g/tree and Nitrofull 120 g/tree. In 2011 frost damage was not correlated with fertilization but was significantly correlated with height classes, showing higher proportion of plants with medium, severe and total damage grades when trees were 100 or less cm tall. Trees with 134 g Triple 15 and 60g Nitrofoska showed the highest heights.

Keywords : Cold resistance; Forest plantations; Potassium fertilization; Frost damage.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )