Is Bere barley specifically adapted to fertilisation with seaweed as a nutrient source?

Abstract

Traditional crofting in Scotland used Bere barley fertilised with seaweed. Bere has known abilities to cope with the marginal, high pH soils without inorganic fertiliser addition. The objective of this study was to assess whether Bere productivity is specifically enhanced when fertilised with seaweed. We grew Bere genotypes in field and glasshouse studies and measured growth, yield, and plant nutrition compared with NPK fertilised plants. It is clear that seaweed was an effective fertiliser for Bere, increasing yield from 2.0 to 4.6 t ha−1 with the addition of 50 t ha−1 seaweed in the year of application. This was dependent on soil type. In pot trials the response was different in alkaline compared to acidic soil, with Bere increasing biomass (from 3.1 to 8.1 g) by > 2.5-fold in NPK treatments only in the former. While seaweed addition improved the availability of micronutrients (Mn from 8 to 36 µg g−1; Cu from 12 to 37 µg g−1; Zn from 40 to 140 µg g−1) for both Bere and commercial cultivars, this only improved biomass production (from 0.2 to 1.9 g) in alkaline soils for the commercial cultivar. It is clear that seaweed is a useful fertiliser for Bere, and under certain conditions the adaptations of some Beres to cope with Mn-deficiency allowed them to take full advantage of the addition of NPK fertiliser. This highlights the need for understanding interactions between alternative fertilisers and genetic adaptation in crops to cope with stresses of marginal environments and help achieve agricultural sustainability.