Effects of combined application of biochar and sludge compost on seeds germination of oil sunflower (Helianthus annuus L.) and water retention capacity in two different soils

Institute of Coastal Environmental Pollution Control, Key Laboratory of Marine Environment and Ecology, Ministry of Education, College of Environmental Science and Engineering, Ocean University of China, Qingdao, Shandong, 266100, China

^* *Corresponding author’s e-mail: 17852023772@163.com

Abstract

Biochar (BC) and sludge compost (SC) have attracted extensive attention because of their multiple benefits in improving soil quality and functionality. However, the effects of combined application of BC and SC on plant growth and soil properties in different soils are unclear. In this study, a woody waste derived BC and a sludge compost from a commercial factory were applied into an agricultural soil and a salt-affected soil collected from the Yellow River Delta to investigate their effects on the germination of oil sunflower seeds (Helianthus annuus L.) and water retention capacity in the two soils using pot experiments. The results showed that the combined application of BC and SC increased the germination potential of oil sunflower seedlings in the farmland soil and salt-affected soil by 2.00–11.00 times and 0.50–5.00 times, respectively. This is because the BC and SC can collaboratively improve soil physical and chemical properties and increased nutrient availability. Additionally, BC and SC increased the maximum water holding capacity (WHC) of two soils by 3.72–18.80%. These results will provide theoretical basis and technical support for the development of biochar technology to remediate degraded and agricultural soil, thus to ensure the sustainable development of agriculture.