Dr. John O’Donovan, a malt barley researcher with Agriculture and Agri-Food Canada (AAFC), recently conducted a study investigating the impact of seeding rate, seeding date, fertility rate (nitrogen rate), stubble type and fungicide use on malt barley quality. O’Donovan worked closely with Dr. Michael Edney of the Canadian Grain Commission’s Grain Research Laboratory to determine that seeding barley at 300 seeds per square metre resulted in higher overall malt quality than lower seeding rates. While there was a slight reduction in plump, higher seeding rates were associated with lower protein and beta-glucan content, and higher friability, due to the positive impact of seeding rate on seed uniformity.
O’Donovan’s best practices for malting barley:
- In general, seeding malting barley relatively early reduces excessive protein
- In most cases, seeding barley at 300 seeds/metre2—generating about 200 to 250 plants/metre2, or 20 to 25 plants/foot2—optimizes overall yield and quality, improves kernel uniformity and reduces protein and beta-glucan levels
- Seeding rates of more than 330 seeds/metre2, however, increase the risk of reduced yield, reduce plumpness and show no great advantage in reducing protein or increasing seed uniformity
- Increasing nitrogen increases yield and kernel weight, but also increases protein and negatively affects nearly all other aspects of malting barley quality, including reductions in fine extract levels—which are very important to maltsters
- Planting barley on barley generally reduces yield and quality, and increases disease as compared to planting barley on canola or field peas
- Barley yields are highest (without significantly increasing the protein levels) when planted on field pea residue