Evaluation of Soil Quality for Forestry
Researchers at Teagasc, with assistance from UCD Forestry Department, have succeeded in identifying the best sites to plant Sitka spruce in Ireland.
Using a soil quality classification system in use in British Columbia, Canada, Dr Niall Farrelly, a Research Officer in Teagasc’s Crops, Environment and Land Use Programme looked at what measures of soil quality in forest soils (soil classification data and a number of physical and chemical variables such as pH, phosphate, magnesium and ammonium levels, etc.) gave the best indication of soil quality in forest soils and how these measures related to the productivity of Sitka spruce in Ireland.
Having investigated the growth of the species in response to various soil quality measures, the researchers found that soil nutrient regime (a classification that classifies soils into homogenous groups based on the level of nutrients available for plant growth) was the best measure of site quality, as it accounted for over half the variation in the growth of the species. Significant increases in yield were achieved with increasing soil nutrient regime. The study also found that soil nutrient regime was closely related to previous land use, where the residual effect of land management resulted in higher growth rates.
“Thus, soil nutrient regime is a good measure of soil quality for use in forestry in Ireland. Importantly, the study established where forest production can be maximised, which is on fresh to very moist sites with rich to very rich nutrient regimes,” explains Dr Farrelly.
“This study means that significant potential exists to increase yields in our planting programme through adequate site selection,” says Dr Farrelly.
The article ‘Evaluation of soil quality for forestry’ is featured in the spring 2012 issue of TResearch, Teagasc’s research and innovation magazine available online at: TResearch