Tag Archives: Triticum aestivum

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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489-498 Z. Kriauciuniene, R. Velicka, S. Raudonius and M. Rimkeviciene
Changes of lignin concentration and C:N in oilseed rape, wheat and clover residues during their decomposition in the soil
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Changes of lignin concentration and C:N in oilseed rape, wheat and clover residues during their decomposition in the soil

Z. Kriauciuniene², R. Velicka¹, S. Raudonius¹ and M. Rimkeviciene²

¹Department of Soil Management, Lithuanian University of Agriculture, Studentu 11,Akademija, LT-53361 Kaunas dist., Lithuania, e-mail: rimantas.velicka@lzuu.lt
²Experimental Station of Lithuanian University of Agriculture, Noreikiskės,LT-53363 Kaunas dist., Lithuania, e-mail: zita.kriauciuniene@lzuu.lt

Abstract:

Field experiments were conducted in 2003–2005 at the Experimental Station of the Lithuanian University of Agriculture to study the changes of lignin concentration and C:N in roots and top residues of winter and spring oilseed rape (Brassica napus L.), winter wheat (Triticum aestivum L.) and red clover (Trifolium pratense L.) after 14, 33, 63, 85 and 116 weeks of decomposition in the soil. Correlation between lignin concentration and amount of dry matter as well as the ratio of carbon and nitrogen in investigated crop residues were estimated.Investigation of crop residue decomposition during the period of 116 weeks showed thatstubble and roots of winter and spring oilseed rape decompose more slowly than their threshing remains, or stubble, and roots of winter wheat and red clover. Dry matter and lignin decomposed and the ratio of carbon and nitrogen in winter oilseed rape residues decreased more slowly than that of spring oilseed rape residues.The ratio of carbon and nitrogen in the decomposing crop residues decreased mostintensively during the 33–63 week period. After that, the concentration of lignin started to decrease, but its significant decline in all investigated crop residues was estimated after 116 weeks of decomposition. Lignin was most decomposed from its concentration peak in the stubble of red clover (37.9%) and least in winter oilseed rape roots (12.8%).Negative correlation between lignin concentration and dry matter amount and betweenlignin concentration and C:N was established in winter and spring oilseed rape, winter wheat and red clover top and root residues decomposing in the soil.

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