Artikkelit kirjoittajalta Leila Urvas
Uuttoajan ja EDTA:n vaikutus metsitettyjen peltomaiden ravinteiden uuttumiseen happamaan ammoniumasetaattiin.
English title: Effect of extraction time and EDTA on acid ammonium extractable nutrient concentrations of afforested agricultural soils.
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The effect of extraction time on the extraction of P, K, Ca, Mg and the effect of EDTA on the extraction of Mn, Fe and Zn with acid ammonium acetate was studied in 196 soil samples collected from afforested agricultural soils. Extraction time (1 hour or ca. 20 hours) did not significantly affect gravimetrically expressed mean concentrations of K, Ca and Mg in mineral soil samples. In peat samples the mean concentration of Ca and Mg with the shorter extraction time was 73% and 81% respectively of the mean concentration obtained with longer extraction time. The mean concentration of P with the extraction time of 1 hour was about 50% of the mean concentration obtained with the longer extraction time in peat and mineral soil samples. Extraction with acid ammonium acetate/EDTA extracted Fe sevenfold and Zn almost threefold compared with acid ammonium acetate alone. Regression models for converting gravimetric and volumetric nutrient values obtained with methods used in agriculture to gravimetric and volumetric nutrient values obtained with methods used in forestry are presented.
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Wall,
The Finnish Forest Research Institute, Kannus Research Station, P.O.Box 44, FIN-69101 Kannus, Finland
Sähköposti:
ei.tietoa@nn.oo
- Urvas, Sähköposti: ei.tietoa@nn.oo
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
Uuttuva kupari viljellyissä eloperäisissä maissa.
English title: Extractable copper in cultivated organic soils.
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The content of acid (pH 4.65) ammonium acetate-EDTA (AAAc-EDTA) extractable Cu was in mould soils (9.6 ±5.7 mg/1 soil) about one and a half times that in peat soils (6.6 ± 4.4 mg/1). There was a close positive dependence between extractable Cu and the total Cu in both soil types. The proportion of extractable Cu on the total Cu was in mould soils (wet combustion 40.0 ± 13.3%; dry ashing 40.9 ± 11.3%) somewhat lower than in peat soils (wet combustion 47.4 ± 13.6%; dry ashing 53.4 ± 19.5%). In mould soils the decrease in soil acidity had an increasing effect on both extractable Cu and total Cu contents of soil. In peat soils the extractable Cu and total Cu contents were lowest between pH(H20) values 5.0 and 5.5, and increased with both increasing and decreasing the soil acidity. The extractable Cu and total Cu contents were highest in mould soils of low humus content and in peat soils having humus content between 60 and 70%.
Keywords: Humus, mould soil, peat soil, pH, total copper
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Jokinen,
Agricultural Research Centre of Finland, Institute of Soils and Environment, FIN-31600 Jokioinen, Finland
Sähköposti:
ei.tietoa@nn.oo
- Urvas, Sähköposti: ei.tietoa@nn.oo
- Hyvärinen, Sähköposti: ei.tietoa@nn.oo
Uuttuva sinkki viljellyissä eloperaisissa maissa.
English title: Extractability of zinc in cultivated organic soils.
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The AAAc-EDTA extractable Zn content in mould soils (2,3±2,0 mg/ l soil) was not dependent on the total Zn content. In peat soils the extractable Zn content (2,0±1,9 mg/l soil) increased with the increase in total Zn content. The proportion of extractable Zn to the total Zn was less than 8% in Zn deficient mould soils but about 40% in Zn sufficient mould soils. In peat soils the corresponding proportions were 30% and 60%. In mould soils the increases in humus content and acidity caused an increase of AAAc-EDTA extractable Zn. In peat soils extractable Zn content increased with increasing humus content up to 65%. The extractable Zn content was highest between pH values 5,0 and 5,5.
Keywords: Extractable zinc, humus content, mould soil, peat soil, pH, total zinc
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Urvas,
Agricultural Research Centre of Finland, Institute of Soils and Environment, SF-31600 Jokioinen, Finland
Sähköposti:
ei.tietoa@nn.oo
- Jokinen, Sähköposti: ei.tietoa@nn.oo
- Hyvärinen, Sähköposti: ei.tietoa@nn.oo
Timotein (Phleum pratense) sinkkipitoisuus turvemaalla.
English title: The zinc content of timothy (Phleum pratense) grown on peat soil.
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The zinc contents of timothy grown on peat soils generally low in zinc were considerably raised by zinc fertilization, even when applied at the low rate of 550 g Zn/ha, in combination with other micronutrients. On peat soil groups with average extrac-table zinc contents of 0,60, 1,40 and 7,22 mg/1 the mean zinc contents of timothy before fertilization were 25,6, 27,1 and 28,9 and after fertilization 28,6, 34,8 and 36,4 mg/kg D.M., respectively. The corresponding increases were 11, 28 and 26 per cent. In general, the zinc contents of timothy in this study did not differ essentially from those measured elsewhere in Finland.
Key words: Phleum pratense, zinc content, agriculture, peat soil, P/Zn.
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Urvas,
Agricultural Research Centre, Department of Soil Science, SF-3J600 Jokioinen, Finland
Sähköposti:
ei.tietoa@nn.oo
Viljelyn vaikutus turpeen ravinnepitoisuuteen.
English title: Effect of cultivation on the nutrient status of peat soils.
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Various effects of cultivation on the properties of peat soils included an increase in the bulk density of top soil. Rises of pH and exchangeable Ca and Mg were attributed to liming. Increases in the available contents of other macro- and micronutrients due to fertilization and other cultivation practices were most substantial in the topsoil but also reached the deeper soil horizons.
In the cases of most nutrients the original trophy of the peat was still distinguishable after several years of cultivation.
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Urvas,
Sähköposti:
ei.tietoa@nn.oo
Etelä- ja Pohjois-Suomen luonnontilaisten turpeiden viljavuuserot.
English title: Comparison of the chemical prperties of virgin peat soils in Southern and Northern Finland.
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Due to climatic differences, vegetational variation occurs even within the same mire types from southern to northern parts of Finland. Accordingly, geographical differences in fertility can be expected.
This material was collected from 338 sites in South Finland and 468 sites in North Finland during the 1960s (Fig. 1). When sampling virgin peat soils in routine soil survey work, three samples were collected from each site; depths 0—20, 20—40 and 40—60 cm. The pH (H2O) and acid ammonium acetate extractable Ca, K, and P were determined from all samples. In addition, N and humus percentages were determined from surface soil samples.
The average pH (H2O) in different layers of Carex dominated peat soils was 0,1— 0,4 pH-units lower in South than in North Finland and the corresponding differences in Sphagnum dominated peat soils were 0,2—0,3 pH-units (Table 2).
Average contents of ammonium acetate extractable potassium and especially calcium and phosphorus were higher in South than in North Finland. One reason for higher soluble nutrient contents in the South may be the lower pH in southern peat soils. Also the mineral subsoil underlaying the peat may have an effect on the fertility properties of the peats. In general, northern mineral soils are coarser in texture and poorer in nutrients than those in the South. The total nitrogen contents of Carex dominated peat soils were 21 per cent higher in northern than in southern peat soils and those of Sphagnum dominated peat soils 17 per cent higher. This may be partly due to the fact that within both peat types (Carex and Sphagnum) the composition of plant species responsible for peat formation varies from south to north. According to the differences in nitrogen contents, the C/N ratios, an index indicating the quality of peat, were smaller in the northern peat soils.
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Urvas,
Sähköposti:
ei.tietoa@nn.oo
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