high humus content causes the soil to be brown
brown_root_rot_fungus is not fungus. humic_shale is humate. brown_rot is plant_disease. if plow occurs then dig occurs. brown_rot_gummosis is not brown_rot. humus is soil. brown_rot_gummosis is brown_rot. brown_root_rot_fungus is fungus. humic_shale is not humate. humus is not soil.