Growth, Yield, and Grain Quality of Barley (Hordeum vulgare L.) Grown across South Korean Farmlands with Different Temperature Distributions

Abstract

Climate change has disrupted several aspects of food systems, but perhaps one of the most alarming effects on global nutrition is the decrease in grain production as well as the reduction in the protein content and quality of the grain. Over the last several decades, due to climate change, suitable areas in Korea for barley cultivation have been moving northward compared to the past. Thus, the objective of this study was to determine how different climatic factors such as temperature impact barley growth at different stages (December, February, and April) and the yield at harvest in four group areas (G1, G2, G3, and G4) with different climates. Differences in the temperatures between areas during the growing season and the variability in growth and yields were noted. Additionally, the chemical composition of the soils and the mineral content of the leaves at the heading stage as well as the main constituents and amino acid composition of the barley seeds grown in different areas were considered. On average, the tiller number/m2, plant height, and dry aboveground plant parts/m2 in G1 areas were lower than in other group areas when measured before overwintering (December), after overwintering (February), and at the heading stage (April). However, there was no difference in these parameters between G2 and G3 areas. In 2020, the order of yield levels was G4 > G2 = G3 > G1. The yield in G1 areas was 37% less than in G4 areas. In 2021, yield levels were similar with the order of yield being G4 = G3 > G1 = G2. Also similar to the prior year, yield in G1 areas was 39% less than in G4 areas. The minimum and daily average temperatures during the growing season (October to June) were in the order of G4 > G3 > G2 > G1. Growth parameters in the colder G1 areas were lower than in other group areas, which suggests that the minimum and daily average temperatures in December, February, and April may be responsible for the lower crop growth and yield. Crude protein, lipid, and ash contents in the G1 and G2 areas were higher than in G3 and G4 areas. There was no variation in most kinds of amino acids between the group areas. Organic matter, available phosphoric acid, potassium (K), calcium (Ca), and zinc (Zn) contents in the soil of G1 areas were higher than in soils elsewhere. In addition, there was no consistency among most other mineral contents in the plants between the group areas. Overall, the growth and yield in G1 areas were lower than in other areas. Thus, it was concluded that these areas were still not suitable for barley cultivation regardless of climate change.