“…For example, while a lumped hydrologic and nitrogen model that provides continuous estimate of pathway loading is robust (Hartmann et al, 2016; Husic, Fox, Adams, Ford, et al, 2019; Sullivan et al, 2019), there are less model‐intensive alternatives such as loadograph separation (Fenton et al, 2017; Mellander et al, 2012; Miller et al, 2017). Loadograph separation only requires nitrate concentration and discharge, which are commonly becoming ubiquitous, particularly with the widespread use of aquatic nitrate sensors that provide continuous estimates of nitrate concentration (Burns et al, 2019). Further, with regard to nitrate sourcing, stable isotopes are commonly employed (Lutz et al, 2019; H. Zhang, Kang, et al, 2020; Wang et al, 2020; Z. Zhang, Chen, Cheng, Li, et al, 2020; Z. Zhang, Chen, Cheng, & Soulsby, 2020) but sources have also been unmixed with elemental concentration data alone (Katz et al, 2011; Yue et al, 2017).…”