Biochar Extract Compounds Alter Germination and Growth of Crop Seed

Positive or negative plant growth effects due to soluble organic biochar compounds are not well understood. Increasing quantities (0 g, 0.5 g, 2.5 g, and 5 g) of four different biochars were extracted with 0.1 M HCl, which were separated and marked as W, X, Y, and Z. Corn and rice seeds were treated with biochar extract solution. The rice straw Y and Z solutions positively affected corn germination, while the cotton straw Z solution negatively affected it. When differences were present, the biochar extract solutions always caused reduction in rice seed germination. The rice straw and cotton straw solutions tended to increase, the wheat straw Y and Z solutions tended to decrease, while little differences were evident in terms of the effects of the Spartina alterniflora solution on corn bud and root length when compared to the control. Increasing the biochar solution extract treatments reduced the rice bud and root length when compared to the control, especially with solution Z. Organic compounds, e.g., triethyl phosphate, 2,4-bisphenol, were present in the solutions, which likely promoted seed growth at lower concentrations. Determining the presence of biochar organic moieties helped with designing biochars for enhanced seed germination, growth, and crop productivity.

Automated summary

The effects of soluble organic biochar compounds on plant growth are not well understood. The extracted biochar solutions had different effects on the germination of corn and rice seeds, with rice straw and cotton straw solutions promoting corn germination, while cotton straw solution negatively affected it. The biochar extract solutions generally caused reduction in rice seed germination. Organic compounds present in the solutions likely promoted seed growth at lower concentrations. Determining the presence of organic moieties in biochar can help design biochars for enhanced seed germination, growth, and crop productivity.