Model-based assessment of organic fertilization as alternative to mineral P under future climate change

Summary

Sustainable agriculture depends on reliable phosphorus (P) supplies, yet global reserves of mineral P fertilizers are finite. Here, we explored whether organic fertilization could serve as a viable substitute for mineral P while sustaining crop yields and soil P under changing climate conditions. Using the calibrated and validated AgroC model with decades of field data from the Bad Lauchstädt long-term experiment site in Germany (with a four-crop rotation of sugar beet, spring barley, potato, and winter wheat), we simulated crop performance and soil P dynamics from 2019 to 2100 under the RCP4.5 and RCP8.5 climate scenarios. The analysis compared five fertilization strategies: mineral fertilization (MIN), two farmyard manure rates (FYM_20 and FYM_30), and two optimized manure regimes (FYM_3