Н. Н. Новиков Field experiments with brewing barley carried out on sod-podzolic medium-loamy soil found that the raising doses of nitrogen application increase the grain yield of barley (by 18- 44%), total protein content and hordein concentration in grain, a-amylase and catalase activity. On the other hand, there was a decrease in the grain unit, globulins, the content of water soluble and non-extractable proteins, and fi-amylase activity resulting in negative effect on brewing qualities of barley grain. Sufficient nitrogen nutrition acoompanied by increased rates of phosphorus and potassium increased the grain productivity of barley, seed germinating ability, a-amylase activity, but decreased fi-amylase and catalase activity and grain protein content ensuring the normative level (less than 12%) that resulted in improved brewing qualities of grain. Basing on experimental data the authors advocate the feasibility of applying novosil phytoregulators for raising the grain productivity of brewing barley and reducing its grain protein content on the backgreound of nitrogen fertilizer application. The authors determined correlations between the concentration of tyrosine in the leafjuice in the phase of the first stem node formation, nitrogen application rates, crop productivity and technological parameters of grain. This indicates the effectiveness of using this indicator to diagnose nitrogen nutrition and forecast the grain quality of brewing barley.
Научная статья 
amylase and catalase activity