Effects of torrefied wood chip and vermicompost application on vegetation growth and nutrient uptake in the Saemangeum reclaimed land

Background In reclaimed land, the growth environment for plants may be unfavorable and the initial establishment and growth of seedlings could be limited because of low nutrient and water availability. Fertilization and control of understory vegetation that competes with seedlings may be of help in ameliorating soil physical and chemical properties, resulting in better seedling growth and reclamation success. However, the amount of nutrients understory vegetation absorbs in this ecological process has been rarely studied. Thus, we aimed to investigate the effect of soil amendment on biomass production and nutrient uptake by weeds in the nutrient-poor reclaimed area. We applied three levels of torrefied wood chip (TWC; 0, 2.5, and 5 Mg ha −1 ) and two levels of vermicompost (VC; 0 and 2.7 Mg ha −1 ) as soil physical improvements and organic soil amendments in reclaimed land in the Republic of Korea, with Populus euramericana used as the crop tree. Results TWC did not influence weed biomass, but 2.7 Mg ha −1 VC significantly increased weed biomass by 21% compared to 0 Mg ha −1 VC treatments. Nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sodium (Na) concentrations in weeds were the highest in control, but there was no statistical difference among treatments. However, VC treatment did marginally increase nutrient uptake in weeds, especially P, K, Ca, and Na. No treatments influenced crop tree height. Conclusion We conclude that VC can be used as an organic source of nutrients in reclaimed soil and that weed management is necessary to increase treatment effects on crop trees in this salt-affected reclaimed land.