Tag Archives: winter cover crops

1934–1943 J. Kuht, V. Eremeev, L. Talgre, H. Madsen, M. Toom, E. Mäeorg, E. Loit and A. Luik
The content of weed seeds in the soil based on the management system
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The content of weed seeds in the soil based on the management system

J. Kuht¹*, V. Eremeev¹, L. Talgre¹, H. Madsen¹, M. Toom¹², E. Mäeorg¹, E. Loit¹ and A. Luik¹

¹Estonian University of Life Sciences, Kreutzwaldi 1, EE51014 Tartu, Estonia
²Estonian Crop Research Institute, J. Aamisepa 1, EE48309 Jõgeva, Jõgeva Vald, Estonia
*Correspondence: jaan.kuht@emu.ee

Abstract:

In 2008 an experiment was set up on the field in Eerika experimental station (Estonian University of Life Sciences) as a 5-field crop rotation: barley (Hordeum vulgare L.) with undersown red clover, red clover (Trifolium pratense L.), winter wheat (Triticum aestivum L.), pea (Pisum sativum L.), potato (Solanum tuberosum L.). The objective of the study was to measure the content of weed seeds in the soil and to evaluate the diversity of the species at the beginning of the period of organic production in 2011. In conventional farming systems without fertilizer (Con I) and conventional farming with mineral fertilizer (Con II) herbicides were used for weed control. All the crops in Con II system received P 25 kg ha-1 and K 95 kg ha-1, but the application rates of mineral nitrogen fertilizer differed. In organic systems (Org I – organic farming based on winter cover crop and Org II – organic farming based on winter cover crop and manure), the winter cover crops (ryegrass after winter wheat, winter oilseed rape after pea, winter rye after potato) were sown after the harvest and were ploughed into the soil as green manure in spring. Organic farming systems (Org II) had a negative effect on the content of weed seeds in the soil (2.0–22.7% less seeds than in other variants). The seeds of Chenopodium album were the most abundant among summer annual weeds and the seeds of Viola arvensis among winter weeds in the soil. Organic farming measures increased the domination of Chenopodium album – the dominance index D’ was increased by 0.09–0.14 compared to conventional variants. The content of seeds of winter weed Viola arvensis in Org II variant was decreased by 82%. The index of species evenness J’ and Shannon Wiener diversity index H’ were lower in organic plots by 0.10–0.18 and 0.60–0.19, respectively. Org II variants showed the best results based on the decrease of soil weed seed bank and distribution of the weed species.

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1372-1379 J. Kuht, V. Eremeev, L. Talgre, H. Madsen, M. Toom, E. Mäeorg and A. Luik
Soil weed seed bank and factors influencing the number of weeds at the end of conversion period to organic production
Abstract |
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Soil weed seed bank and factors influencing the number of weeds at the end of conversion period to organic production

J. Kuht*, V. Eremeev, L. Talgre, H. Madsen, M. Toom, E. Mäeorg and A. Luik

Estonian University of Life Sciences, Kreutzwaldi 1, EE51014 Tartu, Estonia *Correspondence: jaan.kuht@emu.ee

Abstract:

In 2008 an experiment was set up on the field in Eerika experimental station (Estonian University of Life Sciences) as a 5-field crop rotation: red clover, winter wheat, pea, potato and barley undersown with red clover. The objective of the study was to measure the content of weed seeds in the soil and to evaluate the diversity of the species at the end of the period of converting to organic production. In conventional farming systems without fertilizer (Conv I) and conventional farming with mineral fertilizer (Conv II) herbicides were used for weed control. All the crops in Conv II system received P 25 kg ha-1 and K 95 kg ha-1, but the application rates of mineral nitrogen fertilizer differed. In organic systems (Org I – organic farming based on winter cover crop and Org II – organic farming based on winter cover crop and manure), the winter cover crops (ryegrass after winter wheat, winter oilseed rape after pea, winter rye after potato) were sown after the harvest and were ploughed into the soil as green manure in spring. The content of annual weed seeds was the lowest in red clover that had 17.7% less weed seeds in the soil of Org II system compared to control (Conv I). In winter wheat the content of winter annual weed seeds was 50–76% higher compared to other crops. By the end of 2009 the content of organic carbon (Corg %) in the soil had increased significantly in both organic systems which results in higher activity of organisms that decrease the viability of weed seeds.

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