Influence of liming and pH-value in soil on yield and protein content of <em>Lupinus angustifolius</em> L.

Abstract

Grain yield and protein content of 12 different narrow-leafed lupins were compared in field studies at different soils. Two year trials were carried out in contrasting soil types, acid soils with a pH of 5.8 and calcareous soils with a pH of 7.1. Plants grown in the calcareous soils showed leaf yellowing, whereas the yellowness index (chlorosis score) did not negatively correlate with the plant high and the final grain yield (Spearman, P ≥ 0,05). In 2004, the mean yield of lupin grains on the acid soil was 3.1 t/ha and on the calcareous soil 2.0 t/ha. The following year the level of the yield was lower with 2.9 t/ha or 0.7 t/ha, respectively. The differences in yield between the locations with high and low pH were significant and varied between 0.1 t/ha and 3.1 t/ha.

In the year 2004 and 2005, the mean protein content of the lupin assortment was always higher on the acid soils (30.8% and 30.9%) in comparison with calcareous soils (20.7% and 20.2%). High pH decreased significantly the protein content.

The influence of liming of acid soils in comparison to an unlimed soil on grain yield and protein content of 10 narrow-leafed lupins was studied in a further field experiment. The pH of the unlimed soil (5.8) could be decreased with a lime-application of 3 t/ha and 6 t/ha to a pH of 6.1 or 6.4, respectively. Liming of acid soils did not effected significantly the mean values of grain yield and the protein content of investigated lupins, neither in the single year 2007 and 2008, nor in the mean of the years.