method for improving soil quality, soil quality improvement agent, and soil quality improvement agent composition

摘要

The present invention is a method for improving soil quality, wherein a lignin decomposition product having a nitrobenzene alkaline oxidation aldehyde yield of 5% by weight or more, an average molecular weight of 300 or more and 100,000 or less, and a water contact angle of 15 ° or more is provided to the ground.