Effects of different row distances and seed densities on yield and quality of blue lupins (L. angustifolius) in organic farming

Summary

Blue lupins have become more important in animal feeding due to increasing organic animal husbandry. The high protein content of blue lupins shows the best protein quality of the home-grown grain legumes combined with low starch content. The feed quality of blue lupins can be analysed very quickly and cost-effi ciently with NIRS. Weed infestation in pure stands of blue lupin is often a problem. Mixed cropping systems are a good alternative for weed suppression, but the yield percentage of blue lupins in mixed cultivation is low.
Weed infestation can be reduced by hoeing. For this, blue lupins were cultivated in wider row distances (25.0 cm, 37.5 cm) with the possibility of hoeing, and compared with the cultivation to 12.5 cm row distance (only harrowing). Field experiments were conducted in the years 2006 to 2008 in combination with two different cultivars [Boruta (determined type), Bora (branched type)] and two seed densities (normal: 100%, reduced: 75% of the seed rate).
The results show a signifi cant effect on grain yield for all tested factors, but also an interaction between year and cultivar, and year and seed rate. Yields of the row distance 12.5 cm and 25.0 cm were on the same level, with 2.39 and 2.47 t ha-1 DM,; but yield of the row distance 37.5 cm was signifi cantly lower (2.19 t ha-1). The protein content was not affected by row distance, but yield of protein was the lowest in the variant with 37.5 cm row distance.