重庆三峡库区柑橘园土壤酸碱度及有效氮磷钾的含量特征

Characteristics of Soil pH and Available NPK Contents of Citrus Orchards in Chongqing Sanxia Reservoir Area

为了解重庆市柑橘园土壤酸碱度及有效氮磷钾的含量状况及变化特征,对重庆市8个有代表性柑橘种植区县的土壤农化样（树冠周围）和背景样（树间未受施肥影响的对照区）进行采样分析。结果表明：87.6%的植桔土壤pH呈下降趋势,平均降幅为6.9%,51.5%的柑橘园土壤pH〈6.5,与背景样相比,土壤pH5.5~6.5的果园明显增加,占调查总数的27.4%;6.8%的柑橘园土壤pH〈4.8,不适合柑橘的生长。随着pH的降低,土壤碱解氮、有效磷含量增加,且与土壤pH相关性显著;而土壤有效钾含量变化不大且与土壤pH的相关性并不明显,柑橘园土壤有效氮磷钾整体含量不高。应注意采取相应措施培肥土壤,维持柑橘园土壤的持续生产力。

In order to fully understand characteristics of soil acidity and alkalinity,available NPK contents of citrus orchards in Chongqing,soil pH and available nutrition content of agrochemical soil（around trees crown）and background soil（between tree lines）from eight typical areas in Chongqing.The results showed that soil pH decreased by 6.9%in 87.6% citrus orchards and pH value was below 6.5in51.5%.Soil pH was between 5.5and 6.5in 27.4% and 6.8% citrus orchards did not fit to grow citrus.Along with the decrease of soil pH,available N and available P increased,available K changed slightly.Available NPK were deficient in total,some more measures should be taken to maintain a continued productive forces in citrus orchards.