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Ash spreading on peatlands. Regular Recycling of Wood Ash to Prevent Waste Production – RECASH A Life Environment Demonstration Project LIFE03 ENV/S/000598. Contents. Lack of nutrients on peatlands Deficiency symptoms Nutrient deficiency on different bogs Needle sampling Peat sampling
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Ash spreading on peatlands Regular Recycling of Wood Ash to Prevent Waste Production – RECASH A Life Environment Demonstration Project LIFE03 ENV/S/000598
Contents • Lack of nutrients on peatlands • Deficiency symptoms • Nutrient deficiency on different bogs • Needle sampling • Peat sampling • Effects of ash spreading on peatland • Comparison of nutrient amounts in PK fertilizer and ash • Effects of wood ash spreading on forest growth • Peatland forests and drained peatlands in Finland • Preconditions for ash spreading
Lack of nutrients on peatlands • On nutrient-rich peatlands there is usually enough nitrogen (N). • There may occur deficiency of phosphorus (P), potassium (K), boron (B) or other mineral nutrients. • Nutrient deficiency causes colour symptoms and growth disorders: • yellow-tipped needles or premature shedding of needles (P) • chlorosis of needles (K) • multi-leadered bushy crowns (B) • resistancy decreases • Forest growth is weak inspite of good draining. • Symptoms are easiest to identify on small trees.
Deficiency symptoms (1) Deficiency of phosphorus (P) on pine Deficiency of potassium (K) on pine Photos: Metla, MTT 688 Deficiency of boron (B) on pine
Deficiency symptoms(2) Deficiency of nitrogen (N) on pine Photo: Metla, MTT 688 Deficiency of many nutrients Photo: Kemira 2002
Needle sampling • The need of fertilization on peatland forests can be defined by needle analysis. • The needles are collected during the dormancy of the tree. • A sample contains 1-2 shoots from the south side of the top of 5-10 trees, choosing the biggest and healthiest trees, not growing by a ditch. • The samples with their site information are analyzed. south the shoots are sent for the analysis Picture: Viljavuuspalvelu 1991
Peat sampling • Manual squeezing test (von Post scale): • Colourless water squeezed from peat indicates nitrogen-poor soil. • A more detailed definition of the nutritional status can be done by soil analysis: • A sample is taken from a peat layer in the depth of 5-15 cm. • The final sample of 0,5 litre to be analyzed is combined of several smaller samples. a sample from the depth of 5-15 cm Picture: Viljavuuspalvelu 1991
Effects of ash spreading on peatland • There is no nitrogen (N) in ash, but phosphorus (P), potassium (K) and micronutrients in a balanced combination for trees. • Fertilization effect begins slowly but is long-termed (20-50 years). • Wood ash is alkaline; lower acidity stimulates micro-organism activity, increases the nitrogen intake of trees and decreases the toxic character of other elements. • No phosphorus (P) leaching. • Cadmium does not increase in fungi and berries. • Ash spreading increases undervegetation and breeds the small game stock population.
Comparison of nutrient amounts in PK fertilizer and ash The amounts of nutrients in peat ash are highly dependant on the peat used in ash production. Source: Forestry Centre of Central Finland
Effects of wood ash spreading on forest growth • According to Finnish Forest Research Institute the addition to the volume increment reached by ash spreading is 2-4 m3 /ha/year Ash fertilization in 2001 in Central Finland. Photo in August 2004. The age of the forest is about 100 years. A nutrient-poor mire. Photos: Forestry Centre of Central Finland
Dwarf shrub pine bog. Ash fertilization in 2001. Photo in 2004: Forestry Centre of Central Finland.
Dwarf shrub pine bog. Ash fertilization in 2001. Photo in 2004: Forestry Centre of Central Finland.
Peatland forests and drained peatlands in Finland Proportion of peatlands of forest land Proportion of drained areas of peatlands
Preconditions for ash spreading • Ashspreading, for example 7 tonnes / ha, in Finland costs appr. 210 €/ha + VAT. • Following conditions are required for the state-supported (40-55 % of the costs) ash spreading in Finland: • Needle analysis nutrient imbalance adequate fertility; no need for nitrogen (N) • No need for silvicultural measures • Well drained wetlands • Young development stages of peatland forest • An accepted plan for repairing fertilization