Resumen de Influence of fertilizer placement on yield and protein composition in spring malting barley

E. Johansson, L Haby, M. L Prieto-Linde, S.-E. Svensson

• Soil type and starter fertilizer treatments are known to influence yield, grain protein concentration and grain protein composition in malting barley (Hordeum vulgare L.). Combi drilling of spring sown cereal crops has become more popular recently. Depending on the type of combi drill coulter, the fertilizers are placed differently in relation to the seed (e.g. below or beside) and the placement might influence the nitrogen availability. Thus, the aim was to evaluate if and how fertilizer placement by using different coulter types, influenced grain yield, protein concentration and protein composition in spring malting barley. Fertilizer placement beside and deeper than the sown seed (Vaderstad Rapid Combi coulter) resulted in increased emergence (15%) 20 days after sowing, and increased yield at normal seed rate compared to when the fertilizer was placed just below the sown seed (Tume Nova Combi coulter). Fertilizer placement just below the sown seed led to an increased protein polymerisation compared to fertilizer placement beside and deeper than the sown seed. Nitrogen fertilization led to an increased yield, grain protein concentration, amount of SDS-extractable and -unextractable proteins and small monomeric proteins compared to no nitrogen fertilization. To conclude, nitrogen rate correlated positively with amount of most protein types, while close placement/ availability of nitrogen correlated with protein polymerisation. For grain yield, fertilizer placement just below the sown seeds was negative. Thus, placement of nitrogen might influence the quality of the barley grain for malting purposes.