%0 Research article
%T Effects of soil scarification and previous N fertilisation on pools of inorganic N in soil after clear-felling of a Pinus sylvestris (L.) stand
%A Nohrstedt, Hans-Örjan
%D 2000
%J Silva Fennica
%V 34
%N 3
%R doi:10.14214/sf.625
%U https://silvafennica.fi/article/625
%X Previous analyses of soil water beneath mounds resulting from  scarification have implied that this forestry measure increases leaching  of inorganic N. However, more recent soil-water studies have not  confirmed this assumption. The soil study presented here examined the  pools of inorganic N in different microsites emanating from a simulated  disc trenching, i. e. the mound with underlying soil, the furrow bottom  and the undisturbed soil. The study was made five years after  scarification. The mound itself with underlying soil had a larger pool  of inorganic N than the undisturbed soil. This was mainly because of an  increase in the embedded humus layer, thus implying a larger net N  mineralisation and/or lower losses. However, when pools of inorganic N  per hectare were calculated, taking into consideration that a scarified  area comprises 25% mounds, 25% furrows and 50% undisturbed soil, there  was no increase in pools of inorganic N when compared with an area not  subjected to scarification. This observation supports the finding of the  more recent soil-water studies mentioned, i. e., that leaching seems  not to be influenced by soil scarification. The scarification was made  as a split-plot treatment on main-plots in an old experiment with  different N doses. Thus, the effect of the previous N fertilisation  could also be evaluated. Two N doses were tested beside the unfertilised  control: 720N (3 x 240 kg N ha–1 yr–1) and 1800N (3 x 600 kg N ha–1  yr–1). The last fertiliser application was made six years before the  clearcutting and 13 years before the soil sampling. The previously  fertilised main-plots had larger pools of inorganic N than the control  plots.