Daikon's and chinese cabbage's outer leaves which I cut off can be good compost in a soil in a few month and the process can make the soil fertile.
Daikon's leaves can be pickled with salt and delicious but the soil in my garden is still less nutritious so there is worth "investing" the leaves.
You can see difference in colors of Daikon's leaves which had been buried a few month ago and new leaves. The old ones have turned yellow in a soil.
-- from iPad