撒施复合肥柑橘园土层剖面中氮磷钾分布特征

【目的】为了探明柑橘园连续多年撒施复合肥后土层中氮、磷、钾的分布特征,【方法】2009年对重庆忠县30个紫色土柑橘园和江西省赣南地区3个县(市)24个红壤柑橘园不同土层的碱解氮、有效磷和有效钾含量进行了分析。【结果】柑橘园连续多年撒施复合肥后,不同土壤剖面中碱解氮、有效磷和有效钾含量从上往下逐渐降低。在紫色土柑橘园,碱解氮主要累积在5～25 cm土层,占累积总量的55.76%;有效磷主要累积在0～15 cm土层,占累积总量的79.41%;有效钾主要累积在5～25 cm土层,占累积总量的54.18%。在红壤柑橘园,碱解氮主要累积在10～30 cm土层,占累积总量的46.12%;有效磷主要累积在0～10 cm土层内,占累积总量的76.78%;有效钾主要累积在3～20 cm土层,占累积总量的50.56%。【结论】氮肥撒施后在土壤中移动能力较强,而磷肥在土壤中难于移动,钾肥介于氮肥和磷肥之间。

Distribution of nitrogen,phosphorus and potassium in citrus orchard soil profile after long-term application of compound fertilizer

【Objective】The study was carried out to investigate the distribution of nitrogen(N),phosphorus(P) and potassium(K) in citrus orchard soil after long-term broadcasting application of compound fertilizer.【Method】 The contents of alkali hydrolyzable-N,available P and available K were analyzed in the samples collected from different profiles of soil in many citrus orchards including thirty purplish soil orchards in Zhongxian county of Chongqing and twenty four red soil orchards in southern Jiangxi province in 2009.【Result】The results showed that the contents of the alkali hydrolyzable-N,available P and available K gradually decline from surface layer of soil to deep layer.The 55.76% and 46.12% of alkali hydrolazable-N distributed in 5 to 25 cm depth of purplish and 10 to 30 cm of red soil,respectively.79.41% of available P was observed in 0 to 15 cm depth of purplish soil and 76.78% in 0 to 10 cm depth of red soil;54.18% and 50.56% of available K was accumulated in 5 to 25 cm depth of purplish soil and 3 to 20 cm depth of red soil,respectively.【Conclusion】The results indicated that by broadcasting application of compound fertilizer,the N had the highest mobility in the soil,followed by K,while the P was the lowest.