Application of compost in spruce forests: Effects on soil respiration, basal respiration and soil microbial biomass : Forest Ecosystem Restoration. Ecological and Economical Impacts of Restoration Processes in Secondary Coniferous Forests

2000

S. 61-69

2 Abb., 2 Tab., 29 Lit.

Unselbständiges Werk

200072862

Our objective was to assess the effect of compost application on soil respiration, soil basal respiration and soil microbial biomass of two mature Norway spruce plantations at a silty soil in Solling (SL) and at a sandy soil in Unterlüß (UL), Lower Saxony, Germany. In late summer 1997, 11.4 kg m®¬ of mature compost from separated organic household waste was applied to the soil over two-year-period. Application of compost significantly (p<0.05) increased soil respiration rates by 24$ from 5.1 to 6.3 Mg C ha®Ü (SL) and by 65% from 4.2 to 7.0 Mg C ha®Ü (UL) in 1998. The effect of compost on soil respiration rates was weaker at both sites in 1999. Soil respiration rates increased by 20% from 5.0 to 6.0 Mg C ha®Ü (p=0.06) in SL and by 46% from 4.0 to 5.8 Mg C ha®Ü (p<0.05) in UL. Twenty-one month after the application of compost the basal respiration at 22°C and microbial biomass C were measured from the sieved upper organic layers >2mm and <2mm and from the mineral soils from 0-5 cm, 5-10 cm and 10 to 20 cm depth. Basal respiration rates of the compost plots decreased in the upper organic layer by 1 to 44% and increased with one exception in the mineral soils by 2 to 29%, but the change was only significantly (p<0.05) different in the organic layer fraction <2mm of SL. Basal respiration rates and microbial biomass C showed the same pattern and were positively correlated in the control plots (R¬=0.96) and the compost plots (R¬=0.96). The effect of compost on microbial biomass C was stronger in the upper organic layers and the mineral soils. Microbial biomass C significantly (p<0.05) increased in the mineral soils by 22% (SL, 0-5 cm depth) and 50% (UL, 0-5 cm and 10-20 cm depth). This study suggests that superficial application of compost may improve the nutrient availability and microbial activity in the mineral soil of spruce plantations.