Tag Archives: Latvia

094–111 J. Gailis, I. Turka and M. Ausmane
Soil tillage and crop rotation differently affect biodiversity and species assemblage of ground beetles inhabiting winter wheat fields
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Soil tillage and crop rotation differently affect biodiversity and species assemblage of ground beetles inhabiting winter wheat fields

J. Gailis*, I. Turka and M. Ausmane

Latvia University of Agriculture, Faculty of Agriculture, Institute of Soil and Plant Sciences, Liela street 2, LV-3001 Jelgava, Latvia
*Correspondence: janis.gailis@llu.lv

Abstract:

This paper continues studies on ground beetles (Carabidae) in differently managed winter wheat (Triticum aestivum) fields in Latvia. The main task of those studies was to assess how different soil tillage regimes (ploughing and non-inverse tillage) and different pre-crops (winter wheat and spring rapeseed (Brassica napus) affect assemblage and biodiversity of ground beetles in winter wheat fields. The research was carried out in the Latvia University of Agriculture Research and Study Farm ‘Pēterlauki’ (56°30’39.38’’N; 23°41’30.15’’E) during vegetation season of 2013. The results were compared with the results of similar research carried out at the same place during 2012. Totally 57 ground beetle species were observed in studied fields in 2013. Total species assemblage varied between both consecutive vegetation seasons of the research, however these were minor differences not connected with studied agro-ecological factors. Dominance structure of ground beetle species was significantly different between both vegetation seasons – species which were dominant and subdominant in 2012 became subdominant and dominant one year later, accordingly. Annual effects of soil tillage regime and pre-crop on ground beetle dominance structure also were observed, however some differences were recognized between both vegetation seasons. In case, if weed control was successful, higher ground beetle biodiversity might be observed in ploughed fields pre-cropped with spring rapeseed. Otherwise, significantly higher ground beetle biodiversity may be observed in harrowed soil independently from the pre-crop.

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123–133 A. Lēnerts, D. Popluga, K. Naglis-Liepa and P. Rivža
Fertilizer use efficiency impact on GHG emissions in the Latvian crop sector
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Fertilizer use efficiency impact on GHG emissions in the Latvian crop sector

A. Lēnerts¹, D. Popluga¹*, K. Naglis-Liepa¹ and P. Rivža²

¹Latvia University of Agriculture, Faculty of Economics and Social Development,
Institute of Economics and Regional Development, Svetes street 18, LV-3001, Jelgava,
Latvia
²Latvia University of Agriculture, Faculty of Information technologies, Liela street 2,
LV-3001, Jelgava, Latvia
*Correspondence: dina.popluga@llu.lv

Abstract:

Within increasing production activity Latvian agricultural sector has become one of the main sources of greenhouse gas emissions (GHG) in Latvia. In 2013, agricultural sector contributed 21.0% of the total GHG emissions originated in Latvia (2310.1 Gg CO2eq). Analysis of agricultural GHG emissions by sources shows that direct N2O emissions from agricultural soils through the usage of synthetic fertilizers are one of the most significant GHG source in Latvia. The usage of synthetic fertilizers is one of the most common widespread agricultural practices in Latvian cropping systems and according to statistical data usage of synthetic fertilizers is constantly increasing, for example, in 2013 it increased by 6.9% if compared with 2012. Taking into account that over-fertilization can lead to negative economic and environmental consequences, such as high production costs, depletion of energy resources, and increased GHG emissions, this research aims to estimate how effective usage of synthetic fertilizers are in Latvian crop farms. In order to achieve the set aim an N fertilizer usage were estimated in four crop farms by giving insight into N balance and N use efficiency (NUE) rate in these farms. Research results suggest that improved N efficiency can be selected as GHG mitigation measure as it reduces N surpluses and the use and production of mineral fertiliser while maintaining yield levels. It was also concluded that improved N efficiency reduces direct N2O emissions from fertilized soils and indirect N2O emissions that occur by the release of NH3.

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