【摘要】 为明确不同施肥措施对土壤酸化的驱动作用，以双季稻田和蜜柚果园为研究对象，探究了常用的氮肥、磷肥以及与有机肥配施方案对土壤酸化速率的影响。结果表明，双季稻田中硫铵+钙镁磷肥、尿素+过磷酸钙、尿素+钙镁磷肥、尿素+钙镁磷肥+有机肥替代20%化肥氮处理的土壤酸化速率分别为24.55、7.42、4.32和–0.81 keq/(hm~2·a)；蜜柚园中有机肥替代20%化肥基础上配施硫酸铵+钙镁磷肥、尿素+过磷酸钙、尿素+钙镁磷肥处理的酸化速率分别为16.96、9.09和6.48 keq/(hm~2·a)，而尿素+有机肥替代40%化学氮肥和全部磷肥+减施20%氮肥处理酸化速率为0.51 keq/(hm~2·a)。硫酸铵处理的氮转化过程、作物养分吸收以及过磷酸钙的酸度是土壤的主要质子源，有机肥或钙镁磷肥的碱性物质可大量消耗质子。稻田中碱性水灌溉和有机氮肥驱动的氮转化过程是重要的质子消耗过程。因此，稻田采用尿素+钙镁磷肥+有机肥替代20%化学氮肥，蜜柚园采用尿素+有机肥替代40%化学氮肥和全部磷肥+减施20%氮肥是抑制土壤酸化的优选施肥配方。更多还原

【Abstract】 To elucidate the driving mechanisms of different fertilization practices on soil acidification, a case study was conducted using double-cropping rice fields and pomelo orchards as experimental systems. The effects of conventional nitrogen and phosphorus fertilizers, along with their co-application with organic fertilizers, on acidification rates were examined. Results demonstrated that in double-cropping rice fields, acidification rates were 24.55, 7.42, 4.32, and –0.81 keq/(hm~2·a), respectively when applying ammonium sulfate+calcium-magnesium phosphate, urea+superphosphate, urea+calcium-magnesium phosphate, and urea+calcium-magnesium phosphate with 20% chemical nitrogen replaced by organic fertilizer. In pomelo orchards, acidification rates were 16.96 keq/(hm~2·a)(ammonium sulfate+calcium-magnesium phosphate), 9.09 keq/(hm~2·a)(urea+ superphosphate), and 6.48 keq/(hm~2·a)(urea+calcium-magnesium phosphate) when combining 20% chemical fertilizer substitution with organic fertilizer, whereas it was 0.51 keq/(hm~2·a) in treatment with urea+organic fertilizer with 40% chemical nitrogen and total phosphorus replacement+20% nitrogen reduction. The nitrogen transformation processes associated with ammonium sulfate application, nutrient uptake by plants, and the acidity of superphosphate constitute were major sources of protons contributing to soil acidification. Conversely, alkaline substances in organic fertilizer or calcium-magnesium phosphate could consume significant protons. In paddy fields, alkaline water irrigation and nitrogen transformation processes driven by organic nitrogen fertilizer were important proton consumption processes. Therefore, the optimal fertilization mitigations strategies are: for paddy fields, replacement of 20% chemical nitrogen with organic fertilizer combined with urea and calcium-magnesium phosphate; for pomelo orchards, replacement of 40% chemical nitrogen and all phosphate fertilizer with urea and organic fertilizer alongside 20% nitrogen reduction.更多还原