Suo - Mires and peat vol. 45 no. 2 | 1994
Rikki viljellyissä eloperäisissä maissa.
English title: Sulphur in cultivated organic soils.
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In mould soils the concentration of acid ammonium acetate extractable sulphur (SAAAc) was 33 mg/l on average and total sulphur (Stot) was 833 mg/l. Corresponding contents in peat soils were 45 and 1209 mg/l, respectively. Average extractability of sulphur was 4.2 % in mould soils and 3.7 % in peat soils. In both soil types the extractability was highest when pH was lowest. Increasing humus contents decreased slightly the extractability of sulphur.
Key words: humus, mould soil, peat soil, pH, extractable and total sulphur
L. Urvas, Agricultural Research Centre of Finland, Institute of Soils and Environment, FIN-3J600 Jokioinen, Finland
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Urvas,
Agricultural Research Centre of Finland, Institute of Soils and Environment, FIN-3J600 Jokioinen, Finland
Sähköposti:
ei.tietoa@nn.oo
Neulasten ravinnepitoisuuksien vaihtelu männyn latvuksessa.
English title: Variation in Scots pine needle nutrient concentrations in relation to position in crown and needle age.
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Variation in nutrient concentrations in Scots pine needles in relation to crown position and needle age was examined at two drained peatland fertilization experiments. Samples were taken from plots which had received NPK fertilizer and from sites which had received only P fertilizer and are now suffering from potassium and phosphorus deficiency. In the NPK fertilized plots, potassium concentrations were the lowest in the needles of the uppermost branchlet and increased down the crown. On plots showing potassium deficiency the situation was the opposite. In both experiments phophorus, magnesium, iron, zinc, and boron concentrations decreased and calcium concentrations increased down the crown but in potassium and phosphorus deficient trees calcium and manganese concentrations decreased down the crown. In both experiments phosphorus, potassium, magnesium and boron concentrations decreased with needle age while calcium, iron and manganese concentrations increased. Zinc concentrations increased in NPK fertilized trees but decreased in potassium and phosphorus deficiency trees.
Keywords: Crown position, needle analysis, nutrient variation, Pinus sylvestris
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Kolari,
The Finnish Forest Research Institute, Box 18, FIN-0I301 Vantaa
Sähköposti:
ei.tietoa@nn.oo
Kaivukaluston aiheuttamat puustovauriot kunnostusojituksessa.
English title: Tree damage caused by excavating machines in ditch network maintenance.
Avainsanat:
forest drainage;
excavator;
ditch cleaning;
work studies;
backhoe;
ditch digging;
environmental protection
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An inventory of tree damage caused by five excavators, four backhoes and one small-size single-track backhoe was carried out in western Finland during the frost free season. The proportion of damaged trees was 1.1-2.4 % in tree stands ditched using backhoes and excavators, if the ditch lines had been opened in advance. The corresponding proportion caused by the single-track backhoe was 0.9%, if the ditch lines had not been opened in advance. The damage to tree stands was affected by the machine type, the work type and the width of the opened ditch line. Excavators caused more stem damage in the ditch cleaning than backhoes did (p<0.02). The mean distances of the damaged trees from the center line of the ditch were 226-264 cm on the work sites ditched using backhoes and excavators. The mean DBH of the damaged trees was 8-10 cm depending on work and machine type. The optimum width of the ditch line for the different machine types was assumed to be 400-500 cm when considering the growth losses of tree stand, the tree damage and the work productivity.
Keywords: backhoe, ditch cleaning, ditch digging, environmental protection, excavator, forest drainage, work studies
R. Lauhanen, The Finnish Forest Research Institute, Kannus Research Station, FIN-69101 Kannus, Finland
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Lauhanen,
The Finnish Forest Research Institute, Kannus Research Station, FIN-69101 Kannus, Finland
Sähköposti:
ei.tietoa@nn.oo
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