Physiological Responses and Nitrogen Use Efficiency of Cereal Crops, Barley and Oat, in the Reclaimed Soil

Soil salinization, particularly agricultural lands, is a significant limiting factor to threat the growth and production of economically important cereal crops. The reclaimed agricultural lands in South Korea accounts for approximately 7.1% (112,464 ha), and, of those, the Saemangeum reclaimed land is under construction as a scale of 8,570 ha. The goal of this study is to extend our knowledge through understanding the interactions among growth and production, osmo-protectants and NUE from selected barley and oats varieties. Barley (Hordeum vulgare cv. Jaeanchal, Sogang) and oat (Avena sativa cv. Daeyang, Joyang) with RDA crop cultivation manual were tested in the reclaimed experiment field of National Institute of Crop Sciences (NICS), Gimje, Jeonbuk province from late March to late June, 2023. In barley, biomass production, mineral nutrients and soluble sugars were not different, while spike yield was 1.4 times-higher in Sogang compared to Jaeanchal. Total proline was significant higher in Jaeanchal, however, its level revealed tissue-specific difference; higher in root and spike (Jaeanchal) and in shoot (Sogang). Nitrogen use efficiency (NUE) was positively affected by spike yield, indicating that Sogang was greater NUE than Jaeanchal. In oat, biomass production and spike yield were 1.4 times-higher in Joyang compared to Daeyang, whereas proline and soluble sugars were abundantly accumulated in Joyang. NUE also was higher in Joyang due to greater biomass production including spike yield. Overall, it was concluded that greater spike yield-producing variety revealed higher NUE and lower osmo-protectants levels, and these results imply that the reclaimed soil condition ‘Saemangeum’ might be not a big limitation for barley and oat cultivation with an employment of an appropriate nutrient management if soil physical properties could be amended.