米ヌカ除草 herbicide effect of rice bran

田植えの直後に、水田に米ヌカを撒くと、雑草の成長を抑えることができるそうです。
その理由は次の二つです。
・米ヌカが太陽光を遮る
・米ヌカが腐敗し、土壌表面が酸欠状態になる
なお、肥料としての効果は期待できないそうです。

It is said that scattering rice bran into paddy field right after rice transplanting inhibits the growth of weed.
There are two reasons for that.
・Rice bran blocks the light of the sun.
・Decaying of rice bran make topsoil oxygen-deprived.
In addition, it does not seem to be able to expect effect as manure.