Inconsistencies undermine the conclusion that agriculture is a dominant source of NO in California.

Almaraz . reported that agricultural soils are a dominant source of NO pollution in California (20 to 32% of total statewide NO emissions). However, this conclusion may be undermined by the lack of agreement between their modeled estimates and previously reported empirical measurements, the extrapolation of NO fluxes during hot moments to derive annual estimates, and the overestimation of nitrogen fertilizer consumption in California.

Phosphorus indices: why we need to take stock of how we are doing.

Many states have invested significant resources to identify components of their Phosphorus (P) Index that reliably estimate the relative risk of P loss and incentivize conservation management. However, differences in management recommendations and manure application guidelines for similar field conditions among state P Indices, coupled with minimal reductions in the extent of P-impaired surface waters and soil test P (STP) levels, led the U.S.