一、早衰原因 (一)土肥水管理不当。脐橙园土壤有机质含量低,肥力低,土质差,粘重板结,土层浅薄,PH值高达8.2。1993年在果园中沿果树滴水线挖深100厘米、长100厘米的壕穴进行根群调查的结果是:从60～100厘米处无须根,10～60厘米处须根数为12,20～40厘米处须根数是38,0～20厘米处须根数是18。由此可见,须根主要分布在上层土壤中。在施催芽肥、保果肥和壮果肥时,由于主要 First, the causes of premature aging (a) soil and fertilizer water management is not appropriate. Umbilical orange orchard soil organic matter content is low, low fertility, poor soil quality, sticky weight board, shallow soil, PH value of up to 8.2.2 Orchard in the fruit drip line dug deep 100 cm, 100 cm long root ditch investigation The result is: from 60 to 100 cm without roots, 10 to 60 cm at a fibrous root number of 12,20 ~ 40 cm at the number of fibrous roots is 38,0 ~ 20 cm at 18 fibrous roots. This shows that the fibrous roots are mainly distributed in the upper soil. In the budding budding fertilizer, fruit and fertilizer to protect fat, due to the main