Jelly spring oats and sorghum (Poaceae) are the family with the largest biomass of all plants because of their high carbon fixation capacity and deep roots. Hairy vetch (Leguminosae) The symbiotic rhizobia in its roots fix nitrogen and create fertilizer for the next crop. Radish (Brassicaceae) has a high ability to relieve soil compaction and produces a large amount of biomass. Buckwheat (Polygonaceae) grows quickly, absorbs phosphorus fixed in the soil, and supplies phosphorus to the next crop. Sunflower (Asteraceae) attracts beneficial insects such as honeybees. Their extended roots penetrate into the tillage pan. They are also suitable for absorbing nutrients such as phosphorus from the soil and for the proliferation of mycorrhizal fungi. Flax (Linum family) is a plant that mycorrhizal fungi prefer to live in symbiosis with, and they extend their roots deep even in winter.