Wyniki wyszukiwania - Biblioteka Nauki

1

Wheat yield response and seasonal salt profile evolution under irrigation with saline waters in a semi-arid region

100%

Cheraghi S. A. M. , Cheraghi S. A. M.

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2

Effect of Salinity on Soil Respiration and Nitrogen Dynamics

84%

Zeng W.-Z. , Xu C. , Wu J.-W. , Huang J.-S. , Ma T.

Ecological Chemistry and Engineering S

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2013

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tom 20

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nr 3

519-530

EN

A facility of BaPS (Barometric Process Separation) and indoor incubation experiments were used to determine the effect of soil salinity on soil respiration and nitrogen transformation. The rates of soil respiration, gross nitrification, denitrification, ammonium and nitrate nitrogen concentrations and relevant soil parameters were measured. Results showed that soil respiration and nitrification and denitrification rates were all affected by soil salinity. Furthermore, the effect of soil salinity level on nitrification and denitrification rates had a threshold value (EC1:5 = 1.13 dS/m). When soil salinity level was smaller to this threshold value, the rates of nitrification and denitrification increased with soil salinity while they were reduced when soil salinity level was larger than the threshold value. Moreover, the changing law of soil respiration rate with soil salinity was similar with the nitrification and denitrification rates while the variation tendency was opposite. In addition, the transformation form urea to ammonium and nitrate nitrogen was also reduced with the increase of soil salinity and the reduced effect could be expressed by exponential functions.

PL

Proces BaPS (Ciśnieniowy Proces Separacji) oraz inkubacja pokojowa zostały wykorzystane do określenia wpływu zasolenia gleby na jej oddychanie i transformację azotu. Mierzono szybkości: respiracji gleby, całkowitej nitryfikacji i denitryfikacji, a także stężenie azotu amonowego i azotanowego oraz wartości odpowiednich parametrów gleby. Wyniki wykazały, że respiracja glebowa oraz szybkości nitryfikacji i denitryfikacji były uzależnione od zasolenia gleby. Ponadto stwierdzono, że wpływ poziomu zasolenia gleby na szybkość nitryfikacji i denitryfikacji miał wartość progową (EC1:5 = 1,13 dS/m). Gdy poziom zasolenia gleby był mniejszy od tej wartości progowej, szybkości nitryfikacji i denitryfikacji rosły wraz ze wzrostem zasolenia gleby. Jeżeli zasolenie gleby był większe od progowego, to szybkości te malały. Co więcej, zmiany charakteru zależności szybkości respiracji gleby od jej zasolenia były porównywalne z szybkością nitryfikacji i denitryfikacji, podczas gdy tendencja zmian była odwrotna. Ponadto, transformacja mocznika do amoniaku i azotu azotanowego również zmniejszała się przy wzroście zasolenia gleby, a efekt takiego zmniejszania może być wyrażony funkcją wykładniczą.

3

Relationship between vegetation zonation and edaphic factors in a salt-marsh community (Black Sea Coast)

67%

Apaydin Z. , Kutbay H. , Ozbucak T. , Yalcin E. , Bilgin A.

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2009

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tom Vol. 57, nr 1

99-112

EN

The effects of pH, electrical conductivity (EC), soluble cations (Na[^+], K[^+], Ca[^2+], Mg[^2+]), and soluble anions (HCO[3^-], Cl[^-], SO[4^2-]) on vegetation zonation in a salt-marsh community (Black Sea coast) were investigated on two localities at Black Sea Coast differing as to the altitude, community composition and zonation. Three zones (25-80 m wide) - lower, middle and upper were distinguished in each locality along 150 m transect and according to the vegetation types which were analysed with Braun-Blanquet method. The dominant species were following: Juncus acutus L., Salicornia prostrata Pall., Spergularia marina (L.) Gris, Hordeum geniculatum All., Plantago coronopus L. subsp. coronopus, Carex capitellata Boiss. and Bal, Artemisia santonicum L. and Juncus littoralis C. A. Mey. Soil samples were taken down to 50 cm. The results of soil analysis were evaluated by using Canonical Correspondence Analysis (CCA) from winter 1999 to autumn 2000. HCO[3^-] concentration and inundation depth (2.22.21-44 cm) are the environmental variables that correlate the best with axis 1, whereas K[^+] concentration and inundation depth (2.22-21.44 cm) correlate the best with axis 2 during the study period. During winter 1999, HCO[3^-] concentration showed the highest correlation with the canonical axis 1 and associated zone was H. geniculatum. In spring, summer and autumn 2000, inundation depth (3.44-19.11 cm) was the most prominent factor correlated with the first and second axes, respectively, with associated zone of C. capitellata. EC, Na[^+] and Cl[^-] concentrations were decreased during autumn in all vegetation zones except for C. capitellata and Artemisia santonicum zones in which Na[^+] and Cl[^-] concentrations and EC, respectively were increased during autumn. The C. capitellata (Cyperaceae) zone was located on the positive site of axis 1 during autumn 2000 and followed the gradient of inundation depth. S. prostrata, S. marina, H. geniculatum and P. coronopus subsp. coronopus seems to be adapted to the most saline soils, whereas C.capitellata indicates the wettest soils in the studied salt marsh. The Juncus littoralis zone followed the gradient of maximum salinity during autumn of the year 2000, but the zone was not related to the measured increase in soil salinity during winter, summer and spring. In both localities EC, Na[^+] and Cl[^-] concentrations were tended to decrease at upper zones. Inundation regime, K[^+] concentration, and HCO[3^-] concentration are key factors affecting vegetation zonation in studied salt marshes.