Abstract
Determination of barley (Hordeum vulgare L.) nutrient uptake in residue biomass is important for agronomic, economic, and environmental decisions. Improved understanding of grain yield, residue biomass, nutrient uptake, and their relationships are needed. Research determined these factors in 2018 and 2019 from trials of four barley classes (spring animal feed, human food, and malt, as well as winter malt), using three common cultivars of each, at five locations in southern Idaho. Production environment created the largest difference in residue biomass and nutrient uptake. Barley harvest index ranged from 0.46 to 0.52 Mg Mg-1 across feed, food, and malt classes. Compared to previous estimates, nutrient concentrations from the combined dataset were greater than for N, less than for P, and greater than for K. Correlation of grain yields to nutrient uptake (excluding Cu and Fe) had r2 ranging from 0.68 to 0.89. At current prices, economic analysis indicated that fertilizer replacement costs for total residue biomass nutrients were greater than previous estimates and could greatly exceed current sale value. These relationships and value estimates can be used to improve prediction of barley residue biomass production and nutrient uptake to guide best management practices. The decision of how to utilize these metrics (on-farm, regional, etc.) should be considered based on known variation in measured nutrient and residue data and considered in relation to the proposed task.
Limited research has focused on nutrient uptake and economic value of barley residue biomass (straw + chaff). Production environment created the largest differences in residue biomass and nutrient uptake across barley classes. Average harvest indices (HI) were 0.51, 0.47, 0.52, and 0.46 Mg Mg-1 for feed, food, spring malt, and winter malt barley. N uptake combined across classes was greater than previous estimates, P was less, and K was greater. Fertilizer replacement cost of nutrients removed in residue may far exceed the sale value.