Changes in the soil organic matter supply in topsoil and subsoil caused by cereals grown in crop rotations
2007
Vlcek, V.,Mendelova Zemedelska a Lesnicka Univ., Brno (Czech Republic). Ustav Agrochemie, Pudoznalstvi, Mikrobiologie a Vyzivy Rostlin | Stralkova, R.,Agrotest Fyto, Kromeriz (Czech Republic) | Podesvova, J.,Agrotest Fyto, Kromeriz (Czech Republic) | Pokorny, E.,Mendelova Zemedelska a Lesnicka Univ., Brno (Czech Republic). Ustav Agrochemie, Pudoznalstvi, Mikrobiologie a Vyzivy Rostlin
Soil organic matter (SOM) supply was monitored in field trials from 1993 to 1999 (mean annual temperature 8.9 deg C, total annual precipitation 599 mm, medium Luvi-Haplic Chernozem). The studied plots were a part of nine-crop rotation: alfalfa the 1st and 2nd year, winter wheat, spring barley, sugar beet, spring barley, winter wheat, silage maize and spring barley. SOM supply was measured on four plots as follows: winter wheat after spring barley, winter wheat after alfalfa, spring barley after winter wheat and spring barley after sugar beet. Topsoil (0-30 cm) and subsoil (30-60 cm) samples were taken in 14-d intervals from April to July and SOM content was determined by wet oxidation. Using bulk density, the C content was converted to C supply. The values of SOM differed significantly between the plots and between the two soil layers. The highest ones were found in barley after sugar beet (118 t/ha), the lowest ones in wheat after alfalfa (111 t/ha). In subsoil, there were significant differences between wheat after alfalfa (111 t/ha) and barley after wheat (104 t/ha) plots. When comparing the two cereals, SOM supplies values were higher under barley than under winter wheat in topsoils, whereas this effect was opposite in subsoils. Generally (topsoil and subsoil), the highest supply of SOM was in barley after sugar beet (224 t/ha) and in wheat after alfalfa (222 t/ha). The smallest one was in the variant of wheat after barley (217 t/ha).
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