Effects of wood ash and nitrogen fertilization on fine root biomass and soil and foliage nutrients in a Norway spruce stand in Finland

Abstract

We determined the effects of wood ash fertilization, given together with nitrogen (WAN), and nitrogen given together with P, B and Cu (SSF), on soil and foliage nutrients and fine root biomass in a 45-year-old Norway spruce stand in southern Finland. Fine roots were sampled 9 years, and the soil 10 years after ash (3 t/ha) and nitrogen (150 kg/ha) application. Fine root biomass tended to be lower, the necromass higher, and the fine root distribution relatively deeper on the WAN than on the control and SSF plots. The response of fine root biomass to WAN was probably related to changes in soil acidity. pH, base saturation, total and extractable concentrations of Ca, K, Mg and P, and total B, Cd, Mn, Ni and Zn concentrations in the organic layer were significantly higher on the WAN plots than on the SSF and the control plots with no ash and nutrient addition. On the WAN plots, the pH was 1.2 pH-units higher, the exchangeable Ca concentrations fourfold and those of Mg over twofold compared to the control plots. WAN increased the concentrations of K but decreased those of Mn and Ni in the needles compared to the control and SSF treatment. Even though ash and nitrogen fertilisation tended to decrease the fine root biomass, this decrease was not likely to affect tree growth during a 10-year period.

Combined effects of loose wood ash and carbon on inorganic N and P, key organisms, and the growth of Norway spruce seedlings and grasses in a pot experiment

“…Thus the increasing root/shoot ratio at high C availability to decomposer fungi provides evidence for below-ground competition. Also in accordance with the theory, combined wood ash and nitrogen fertilization increased the fine root biomass in a 45-yr old Norway spruce stand (Helmisaari et al 2008).…”

“…The humus was collected in May from an 85-year old Myrtillus-type Norway spruce forest. The forest floor C/N ratio is ∼30 irrespective of felling history (SiiraPietikäinen et al 2001;Helmisaari et al 2008). The organic layer harboured diverse soil micro-and mesofauna.…”

“…), is known to be sensitive to disturbance such as changing pH especially in conifer microcosms (Liiri et al 2001). Loose ash increased humus pH in a Norway spruce stand ten years after application (Helmisaari et al 2008). Decreasing abundance of fungal-feeding nematodes (Liiri et al 2002a) and enchytraeids (Liiri et al 2001(Liiri et al , 2002a in nonamended microcosms on one hand, and increasing biomass of decomposer fungi and fungal-feeders after C amendment on the other hand (e.g.…”

Effect of wood ash and nitrogen fertilization on soil chemical properties, soil microbial processes, and stand growth in two coniferous stands in Finland

“…A decrease in soil acidity and an increase in base saturation following the application of loose wood ash to forested mineral soils have been widely reported (Khanna et al 1994;Bramryd and Fransman 1995;Kahl et al 1996;Saarsalmi et al 2001Saarsalmi et al , 2004Saarsalmi et al , 2005Ludwig et al 2002;Brunner et al 2004;Helmisaari et al 2009). The effect of wood ash on the acidity of the organic layer can be of long duration (Saarsalmi et al 2001).…”

Short-term responses of soil chemistry, needle macronutrients and tree growth to clinker dust and fertiliser in a stand of Scots pine

“…Liming and base cation fertilisation of acidic forest soils did not cause significant reduction in the currentyear needle Mn concentration in 33-year-old Scots pine stand after 4 years (Grønflaten et al 2005). Over a longer period, after 10-12 years, the improvement in Mn nutrition as indicated by reduced Mn concentrations are reported in needles of Scots pine and Norway spruce affected by wood ash or the wood ash with N treatments (Saarsalmi et al 2005;Helmisaari et al 2009). …”