A.出苗40%時(shí),要揭開薄膜 B.幼苗剛出土?xí)r,要保持濕潤(rùn) C.淺鋤除草 D.幼苗長(zhǎng)出3-5個(gè)真葉時(shí)進(jìn)行間苗移苗
A.1倍 B.2~3倍 C.4-5倍
A.1-2 B.1-3 C.3-5 D.5-10