Optimal phosphorus (P) management is essential in order to achieve sustainable crop production under ley farming system. Manure-based fertilizer represents an alternative to mineral fertilizer to produce forage across tillage systems. Our objective was to investigate the effects of mineral fertilizer [MIN] vs. liquid dairy manure [LDM]) and chisel plough [CP] vs. moldboard plough [MP] on soil P dynamics under a long-term ley farming system. Cumulative P inputs, P offtake and P budget were determined by summing cyclic values across eight 3-yr cycles (1993–2016). Soil test P was determined across six 3-yr cycles (1999–2016) by the Mehlich3 method. Crop P offtake was similar between CP and MP or between LDM and MIN. Phosphorus inputs accumulated across cycles were higher under LDM (65–610 kg P ha⁻¹) than under MIN (54–446 kg P ha⁻¹). The cumulative P budget ranged from − 20 to + 150 kg P ha⁻¹ with LDM and from − 33 to + 3 kg P ha⁻¹ with MIN. Despite a tend of decrease of Mehlich3P in upper layers, a higher accumulation in the 0–0.15 m soil depth under MIN than LDM, and under CP than MP was observed. Discrepancies between P budget and soil test P highlighted the complex mechanisms regulating P cycling. Our findings suggest the importance of complete assessment of soil P reserves in soil profile to sustain P management. Long-term experiment is a useful tool for monitoring effects of agricultural practices on soil P dynamics.

最佳的磷（P）管理对于在ley耕作制度下实现可持续的作物生产至关重要。基于肥料的肥料是矿物肥料的替代品，可在整个耕作系统中产生草料。我们的目标是研究长期耕作制度下矿物肥料（MIN）与液态奶肥（LDM）和凿犁[CP]与mold土犁[MP]对土壤磷动态的影响。通过累计八个三年周期（1993-2016年）的循环值，可以确定累积的P输入量，P吸收量和P预算。土壤测试P是通过Mehlich3方法在六个3年周期（1999-2016年）中确定的。CP和MP之间或LDM和MIN之间的作物P吸收相似。在LDM条件下，整个循环积累的磷输入量更高（65–610 kg P ha ^-1）低于最低（54-446 kg P ha ^-1）。累积P预算范围为- 20〜+ 150公斤P公顷^-1用LDM和从- 33到+ 3公斤P公顷^-1与MIN。尽管上层Mehlich3P有降低的趋势，但在MIN下0-0.15 m的土壤深度中的累积量高于LDM，而在CP下则大于MP。磷预算与土壤试验磷之间的差异突出了调节磷循环的复杂机制。我们的发现表明，全面评估土壤剖面中土壤磷储量对维持磷管理的重要性。长期实验是监测农业实践对土壤磷动力学影响的有用工具。