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Short-term inventory of GHG fluxes in sSemi-natural and anthropogenized grassland

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Balezentiene L., Bleizgys R.
Polish Journal of Environmental Studies
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2011
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tom 20
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nr 2
Climate change accelerates global warming and has thus become an increasing concern with need for prompt solutions. This process occurs due to increased atmospheric green house gas (GHG) emissions. The agro sector (crop and livestock agriculture) contributes 10 to 12% per year of the total global anthropogenic emission and tends to increase. Most agricultural GHG emissions are generated by intensively fertilized soils, enteric fermentation, and manure management. Remarkable GHG fluxes occurred from grasslands which occupy 69% of global agricultural land. The aim of this investigation was to evaluate and estimate GHG emissions in natural and abandoned grassland improved by managed fertilizing. Experimental data sets cover grassland (clay loam topsoil over silt loam, Calc(ar)i-Endohypogleyic Luvisol) abandoned more than 20 years, which has subsequently been fertilized with different rates of N and multiple NPK. Direct CO₂, N₂O, and CH₄ emissions were measured in differently studied treatments (semi-natural sward: Control (0), N⁶⁰, N¹²⁰, N¹⁸⁰, N²⁴⁰, N¹⁸⁰P¹²⁰, N¹⁸⁰K¹⁵⁰, N⁶⁰P⁴⁰K⁵⁰, and N¹⁸⁰P¹²⁰K¹⁵⁰; cultural pasture: N¹⁸⁰P¹²⁰K¹⁵⁰) during vegetation period (2009). Decreasing tendency of emission fluxes was determined during vegetation period and employing lower fertilizer rates. Therefore, appropriate fertilizing rate (N⁶⁰P⁴⁰K⁵⁰) of extensive grassland should be considered for its mitigating impact on climate change.
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Effect of 5 years long cessation of grazing on methane uptake in a semi-arid grassland

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Zhou X., Hao Y.
Polish Journal of Ecology
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2010
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tom 58
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nr 4
Grazing exerts a key role in nutrient cycling in grassland ecosystems, however, little is known about the effe cts of short-term enclosure on methane (CH₄) fluxes in a semi-arid steppe biome like this of Inner Mongolia. CH₄ fluxes were measured in the Leymus chinensis (Trin) Tzvel. grassland using static chamber and gas chromatography (GC). Measurements were carried out twice per month over a growing season in 2004 at the two sites (one fenced since 1999 (UG99) and the other subjected to freely grazing (FG)). All CH₄ fluxes were positive, indicating that this grassland functioned as the active atmospheric CH₄ uptakes. During this period, the UG99 site (57.6 ± 6.7 μg C m⁻² h⁻¹) had significantly higher mean CH₄ uptake in comparison to the FG site (37.0 ± 6.3 μg C m⁻² h⁻¹). A significant liner negative correlations between CH₄ uptake and soil moisture (0–5 cm) at the both sites were found (P <0.05). The results indicated that short-term enclosure was helpful to improve CH₄ uptake in this area.
3
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Habitat occurrence and nutrition value of Achillea millefolium L. in grasslands

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Alberski J., Grzegorczyk S., Kozikowski A., Olszewska M.
Journal of Elementology
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2009
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tom 14
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nr 3
429-436
In 1998-2000, in the area of Olsztyn Lake District, 33 plant communities on seminatural grasslands with a high percentage of Achillea millefolium L. were analyzed. The analyzed objects were located on very light, light, medium and heavy mineral soils. The species composition was evaluated with Braun-Blanquet method. Soil samples were collected for chemicals analyses. In dry matter of Achillea millefolium L. the content of crude protein, crude fibre, crude ash and macroelements was determined. Meadow-pasture communities with high percentage of Achillea millefolium L. in sward are floristically very valuable, particularly those located on light and medium soils. Irrespective of soil type, Achillea millefolium L. was accompanied by Poa pratensis, Dactylis glomerata, Festuca rubra, Trifolium repens, Vicia cracca, Heracleum sibiricum and Taraxacum officinale. The heavy soils had a higher content of P, K, Mg, Ca and Na, whereas very light soils contained more humus. Achillea millefolium L. contained 110-121 g⋅kg-1 crude protein, 249- -309 g⋅kg-1 crude fibre and 97-123 g⋅kg-1crude ash, much P, K and Ca irrespective of soil type and much Mg (3.1 g⋅kg-1) on very light soils.
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