Ermittlung der Vorfruchtwirkung unterschiedlicher Wintererbsengenotypen in Rein- und Gemengesaat
2007
Urbatzka, Peer | Graß, Rüdiger | Schüler, Christian | Heß, J.
In organic farming the cultivation of leguminous crops is one of the most important sources of nitrogen (N). However, in the case of winter field peas, the amount of N fixed, N supply to the subsequent crop and N balance there are hardly any published data. Therefore, the pre-crop effect of six genotypes of winter pea (five regular leaf type, one semi-leafless cultivar) and one semi-leafless spring pea cultivar in single and mixed cropping (with rye spring barley respectively) was examined in three suc-cesive growing seasons (2003/04-2005/06). Immediately after harvest, a catch crop was sown and sampled during the first half of October to determine biomass dry matter and N uptake. In single cropping, N uptake by the catch crop was usually significantly higher after regular leaf type peas in two years, whereas in mixed cropping it was only in one (p<0.05). It is suggested that response of N uptake was - among other possible factors (like e.g. soil tillage after harvest) – due to the mineralized N content in soil at harvest as both correlated significantly (R² between 0.53* and 0.79***, with exception of semi-leafless winter pea (R²=0,19)). It is very important to protect the large N quantities after conventional leafed winter pea cultivars as a sole crop against leaching. Results for the third experimental season will be presented at the conference.
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