The Effect of Sowing Rate and Cultivation Days Under LED Red and Blue Light on Barley Seedlings

LIN Kunming; LIU Wenke

doi:10.3969∕j.issn.1004-440X.2025.03.002

Abstract：This study focuses on barley seedlings(Fudamai No.1)as the research object.The seedlings were cultivated in an LED red-blue light plant factory(light intensity 200 μmol/m2·s-1,light quality R:B=4:1,photoperiod16/8 h).After 3 d of seed germination,the seedlings were subjected to light cultivation(photoperiod 16/8 h).The experiment included 5 treatments:the control group was irrigated with distilled water,with a seeding amount of 340 g/tray(W1.0)and a density of 2.48 kg/m2.The experimental groups were irrigated with nutrient solution,with seeding amount of 340 g/tray(N1.0),510 g/tray(N1.5),680 g/tray(N2.0),and 850 g/tray(N2.5).Harvesting was conducted on 7 d,10 d and 13 d of cultivation,and the biomass indicators such as dry and fresh weight,plant height,as well as quality indicators such as sucrose,soluble sugars,amino acids,and soluble protein content were measured.The results showed that on 7 d,the plant height and dry/fresh weight of barley seedlings were positively correlated with the seeding amount.Compared with W1.0,the seeding amounts of 680 g/tray and 850 g/tray resulted in higher soluble sugar and sucrose content,while the amino acid content was higher at the seeding amounts 340 g/tray and 510 g/tray.The soluble protein content initially increased and then decreased with the seeding amount.The barley seedlings irrigated with distilled water had significantly lower plant height and dry/fresh weight compared to those irrigated with nutrient solution,but had significantly higher soluble sugar,sucrose,and amino acid content.On 10 d and 13 d,the growth rates of plant height and yield in all treatments were lower compared to 7 d.The contents of the four quality indicators in each treatment followed a trend of first increasing and then decreasing with the increase in cultivation days.For most treatments,the content of quality indicators in barley seedlings peaked on 10 d.Based on a comprehensive consideration of yield,economic benefits and quality,it was determined that for hydroponic barley seedlings,irrigating with nutrient solution and using a seeding density of 4.96 kg/m2 was optimal by 7 d of cultivation.