Increasing the range of legume crops for Finnish crop rotations

Abstract

Europe depends on synthetic N fertilizer for crops, and on imports for 70% of its plant protein requirements, and has little influence on the prices of these commodities. Since 2007, we have screened over 50 accessions of 10 grain legume species for adaptation to Finnish growing conditions, initially at Viikki and subsequently also at Mikkeli and Jokioinen. The trials are in randomized complete blocks with 4 replicates and are generally managed with appropriate herbicides, fungicides and pesticides as required to demonstrate yield potential. No imported cultivar of faba bean (Vicia faba) has been significantly earlier than cv Kontu, but some have matured at much the same time and have shown higher yield combined with greater resistance to drought and chocolate spot disease (Botrytis fabae), while sources of earliness have been identified in larger germplasm screens. This species is best adapted to heavy clay soils with a neutral to alkaline pH. With a protein content around 30% and average yields over 3.5 t/ha, faba bean yields more protein per hectare than any other crop in Finland. The narrow-leaf lupin (Lupinus angustifolius) cvs Sonet and Haags Blaue have been shown to be suitable for growing in Finland, with growing seasons of about 100 days or 1000 growing degree-days above 5°C (GDD). The species is particularly adapted to acid sandy soils and in 2011, 91 ha of these cultivars were grown, mostly in Pohjanmaa and Satakunta. Expected seed yields are about 2 t/ha, with protein content around 34-36%. While primarily a feed crop, it is also of interest for food ingredients. Several Canadian lentil (Lens culinaris) cultivars are also suitable, with growing seasons of 90-100 days from May sowing. Lentil needs free-draining soils with low organic-matter content and can yield about 1.5 t/ha of food-quality seeds. Autumn-sown lentil overwintered successfully in 2010-2011 under the heavy snow blanket and was resistant to snow mould (Microdochium spp.). White lupin (Lupinus albus) has shown potential as a biomass or forage crop, including in crop mixtures with cereals. Certain modern cultivars produce more biomass than any other annual legume in our trialsand cover the ground well, suppressing weed growth. Most white lupin cultivars are well adapted to mildly acid soils and need good drainage. Seedlings of all 4 species are tolerant of spring frosts. Frost-sensitive species have also been tested but so far have not shown sufficient yield or adaptation. The trials have shown that there is potential to produce legumes in crop rotations in most parts of the Finnish arable zone.