玉米苗期(第1～6片展开叶)根系发育比较快,茎叶生长比较缓慢。此期田间管理的中心任务是:促进根系发育,培育壮苗,达到苗全、苗匀、苗壮、苗齐,为玉米丰收奠定良好的基础。根据我们的经验,要重点抓好“四早二防”。即早查苗补种移栽,早中耕灭茬,早间定苗,早施苗肥,防治杂草、病 Maize seedling stage (1 ~ 6 leaf expansion) faster root development, stem and leaf growth more slowly. The key task of field management in this period is to promote root development, nurture strong seedlings, and achieve complete seedling, uniform seedling, strong seedling and mature seedling, and lay a good foundation for corn harvest. According to our experience, we must focus on the “four early second defense.” That early check seedlings replanting transplanting, early mid-tillage stubble, morning Dingmiao, early Shi Mushi, weeds control, disease