Resumo

PACHECO-ESCALONA, F. Clemencia et al. Nitrogen uptake and growth of Pinus greggii Engelm. Six years after chemical root pruning. Agrociencia [online]. 2007, vol.41, n.6, pp.675-685. ISSN 2521-9766.

Chemical root pruning is a cultural practice in nurseries to improve fibrousness of the root system, among other purposes. In this study nitrogen uptake was quantified in Pinus greggii Engelm. six years after chemical root pruning was applied in a nursery. The treatments were: bag and carpet impregnated with copper (T1); bag impregnated with copper (T2); carpet impregnated with copper (T3); bag without impregnated copper (T4, control). N uptake was determined using a sample of 20 trees after soil application of a 15N marked source (15NH4)2 SO4 and enriched to 49.2%. It was found that T2 caused better N recovery from the marked source in young foliage (p≤0.01). There were no statistical differences among treatments for water status, tree growth, and dry aerial matter production. The analyses of young foliage indicated that chemical root pruning had positive effects in N uptake six years after planting in the field. It is thus inferred that this practices is beneficial during the few first years of establishment in forest plantations.

Palavras-chave : Pinus greggii; fine roots; ¹⁵N.