The past use of phosphorus fertilizers has left of legacy of pollution that we must consider if we are to have any success in cleaning up water quality.
Inasmuch as the runoff of nitrogen is an interstate transport problem, managing the application of fertilizer and loss of nitrogen to runoff should be a high priority for the Federal government.
Potassium…. may emerge as problematic…. as large areas of highly weathered tropical soils….are converted to agriculture.