Edge-Of-Field Evaluation of the Ohio Phosphorus Risk Index.

摘要: The Phosphorus Index (PI) has been the cornerstone for phosphorus (P)-based management and planning over past twenty years, yet field-scale evaluation of many state PIs limited. In this study, P loads measured in surface runoff tile discharge from 40 agricultural fields Ohio with prevailing practices were used to evaluate PI. Annual highly variable among (dissolved reactive P: 0.03-4.51 kg ha, total 0.03-6.88 ha). Both annual dissolved ( = 0.36, < 0.001) 0.25, significantly related PI score. relationship between load score substantially improved when averaged field values 0.71, 0.73), indicating that should be utilized average risk loss, rather than as an tool. Comparison other established local national metrics resulted large differences potential recommendations monitored fields. near term, revision categories using loading thresholds is needed. To meet minimum criteria tools, future research efforts focus on data (i) incorporate new input factors (i.e., application timing leaching potential) into PI, (ii) calibrate validate provide better assessments recommendations.