Evaluation of six phosphorus extraction methods for compliance testing of recycled P fertilizers Hernandez-Mora, Al. Duboc, O. Bünemann, E. K. Ylivainio, K. Lombi, E. Symanczik, S. Horn, D. Delgado, A. Abu Zahra, N. Zuin, L. Doolette, C. L. Eigner, H. Santner, J. other https://orgprints.org/id/eprint/56653/ /id/eprint/56653/1/2025_Hernandez-Mora%20P%20fertilizer%20extractions.pdf open access 2025 Recycled fertilizer Compliance testing Phosphorus extraction Neutral ammonium citrate Fertilization efficiency Nutrient availability Abacus FiBL1012803 Lex4Bio