Tag Archives: carbon

559–573 M. Latati, N.Y. Rebouh, A. Aouiche and M. Laouar
Modeling the functional role of the microorganisms in the daily exchanges of carbon and nitrogen in intercropping system under Mediterranean conditions
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Modeling the functional role of the microorganisms in the daily exchanges of carbon and nitrogen in intercropping system under Mediterranean conditions

M. Latati¹*, N.Y. Rebouh², A. Aouiche³ and M. Laouar¹

¹Ecole Nationale Supérieure Agronomique, Département de Productions Végétales. Laboratoire d’Amélioration Intégrative des Productions Végétales (C2711100). Rue Hassen Badi, El Harrach DZ16200 Alger, Algérie
²University of Russia (RUDN University) Department of AgroBiotechnology, Institute of Agriculture,Peoples' Friendship, 6 Miklukho-Maklaya street, RU117198 Moscow, Russia
³Ecole Supérieure des Sciences de l'Aliment et des Industries Agroalimentaires (ESSAIA), Avennue Ahmed Hamidouch Route de Beaulieu, El Harrach, DZ16200 Alger, Algérie
*Correspondence: m.latati@yahoo.com

Abstract:

Carbon (C) and nitrogen (N) sequestration in plants and soil micro-organisms is considered as a major phenomenon against global warming. The modeling of this phenomenon aims at highlighting the role that the legumes-cereals mixed crop can play in the reduction of greenhouse gases. It is based on field experiments in maize (Zea mays L.)-common bean (Phaseolus vulgaris L.) intercropped system of the cereal agroecosystem in Setif region of Algeria. For this purpose, the MOMOS model was selected and validated in a calcareous soil and low phosphorus (P) conditions. It revealed some mechanisms that control the C and N sequestration in the compartments of the complex soil-plant-atmosphere-microorganism system. CN modeling results show that the daily growth of intercropped maize with common beans is positively correlated with the microbial CN transformation during the cropping cycle, under limited P and N conditions. Thus, this approach revealed the functional role of rhizobial symbiosis in maintaining the balance between the different C and N exchanges from soil to atmosphere and from atmosphere to soil.

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445-454 K. Balina,, M. Balode, L. Muzikante and D. Blumberga
Impact of synthetic hormone 17α-ethinylestradiol on growth of microalgae Desmodesmus communis
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Impact of synthetic hormone 17α-ethinylestradiol on growth of microalgae Desmodesmus communis

K. Balina¹,*, M. Balode²⋅³, L. Muzikante² and D. Blumberga¹

¹Riga Technical University, Institute of Energy Systems and Environment, Azenes Str. 12/1, LV1048 Riga, Latvia; *Correspondence: karina.balina@rtu.lv
²Latvian Institute of Aquatic Ecology, Daugavgrivas 8, LV1048 Riga, Latvia
³University of Latvia, Faculty of Biology, Department of Hydrobiology, Kronvalda Boulevard 4, LV1010 Riga, Latvia

Abstract:

Microalgae has recently attracted much attention as a feedstock for biogas. Using wastewater as microalgae nutrition is a way how to produce algal biomass with low cost and minimum impact on environment. However, wastewater often is polluted with chemicals like pharmaceuticals which are among the commonly used chemicals in everyday life. The present study was aimed at the toxicity evaluation of a commonly used synthetic hormone, 17α-ethinylestradiol, using freshwater green algae Desmodesmus communis as a biotest organism. Parameters like healthy cell number and photosynthetic activity were determined and used to assess the toxicity. Lowest Observed Effect Concentration (LOEC) and 50% Effective Concentration (EC50) values were calculated for the parameters at different incubation times. It was found out that 17α-ethinylestradiol affects algal cell ability to grow, inhibits cell division and reduce photosynthetic processes in algal cells. Our research shows that inhibitory effect on growth of green algae D. communis start on concentration below 10 µg L-1 (4–8 µg L-1). Concentrations in the range of concentration 80–100 reduce growth by 50%, but concentrations 100–500 µg L-1 induce 100% reduction of growth rate and even calls initial algal cell destruction. Presence of EE2 in wastewater used for algal growth can affect productivity of a microalgae aquaculture.

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487-492 L. Talgre, E. Lauringson, A, Makke
Amounts of nitrogen and carbon returned to soil depending on green manure and the effect on winter wheat yield
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Amounts of nitrogen and carbon returned to soil depending on green manure and the effect on winter wheat yield

L. Talgre, E. Lauringson, A, Makke

Institute of Agricultural and Environmental Sciences, Estonian University of LifeSciences, Kreutzwaldi St. 1, Tartu, Estonia, e-mail: liina.talgre@emu.ee

Abstract:

The trials were carried out during the 2006–08 growing seasons at the Department of Field Crop Husbandry in the Estonian University of Life Sciences. A field experiment was conducted to investigate the effect of green manure treatments on the yield and yield quality of winter wheat. The total phytomass of leguminous green manures ploughed into soil in 2007 varied from 10.3 Mg ha–1 with the bird’s foot trefoil to 13.9 Mg ha–1 with the white sweet clover. The root mass of legumes comprised 37–54% of the total biomass. The amount of carbon applied into the soil with the green material and roots of legumes varied from 4.43 Mg ha-1 to 5.98 Mg ha–1. The amounts of nitrogen were up to 274 kg of N ha–1. The highest wheat yields were attained in treatments with lucerne and red clover as preceding crops. Compared to the N0 treatment, the extra yield reached 3.26 Mg ha–1 with green manures. Both green manures and mineral fertilizers enhanced the quality of the winter wheat yield, but the results did not vary among different green manures.

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517-521 L. Talgre, E. Lauringson, H. Roostalu, A. Astover and A. Makke
Phytomass formation and carbon amount returned to soil depending on green manure crop
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Phytomass formation and carbon amount returned to soil depending on green manure crop

L. Talgre¹, E. Lauringson¹, H. Roostalu², A. Astover² and A. Makke¹

¹ Department of Field Crops and Grasslands, Institute of Agricultural and EnvironmentalSciences, Estonian University of Life Sciences, Tartu, Estonia; e-mail: liina.talgre@emu.ee
² Department of Soil Science and Agrochemistry, Institute of Agricultural and EnvironmentalSciences, Estonian University of Life Sciences, Tartu, Estonia

Abstract:

The trials were carried out during the 2004–2006 growing seasons at the Department of Field Crop and Grassland Husbandry of the Estonian University of Life Sciences. Various green manures and ensuing cereals were studied in respect of phytomass formation and quantity of C returned to soil. The highest amount of organic matter was applied by red clover (8.91 Mg ha–1) and lucerne (8.41 Mg ha–1), and the lowest by unfertilized barley. The total phytomass of pure sowings of barley ranged, depending on the nitrogen fertilizer norm, from 6.55 to 11.54 Mg of dry matter per hectare, of which the grain yield constituted 37.3–43.2%. Sowings of lucerne and red clover added 3.44–3.82 Mg C ha–1 to soil, while sowing of bird’s-foot trefoil supplemented 1.99 Mg C ha–1. Preceding crop determined the phytomass of ensuing crops and the amount of C returned to soil. The amount of C of the oats grown after clover was 5.32 Mg C ha–1, whereas 3.28 Mg C ha–1 was returned to soil. Lucerne pure sowing resulted in 3.17 Mg C ha–1 returned to soil. When oats were preceded by barley (without manure), 2.53 Mg C ha–1 was returned to soil.

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