Phosphorus runoff risk assessment in karstic regions of the United States

Risk assessment policy in the United States.

Colloidal phosphorus in surface runoff and water extracts from semiarid soils of the western United States.

Colloidal particles in runoff may have an important role in P transfer from soils to waterbodies, but remain poorly understood. We investigated colloidal molybdate-reactive phosphorus (MRP) in surface runoff and water extracts of calcareous arable soils from the semiarid western United States. Colloidal MRP was determined by ultrafiltration and operationally defined as MRP associated with parti...

Phosphorus in surface runoff from calcareous arable soils of the semiarid Western United States.

Management strategies that minimize P transfer from agricultural land to water bodies are based on relationships between P concentrations in soil and runoff. This study evaluated such relationships for surface runoff generated by simulated sprinkler irrigation onto calcareous arable soils of the semiarid western United States. Irrigation was applied at 70 mm h(-1) to plots on four soils contain...

Phosphorus Risk Assessment Index Evaluation Using Runoff Measurements

An index to evaluate the phosphorus (P) pollution potential of agricultural fields was proposed by Lemunyon and Gilbert in 1993. Data .from three rainfall simulation studies were used to evaluate the relative importance of the variables in the P index. These studies included plots containing sorghum (Sorghum bicolor L.), winter wheat (Triticum aestivum L), and corn (Zea mays L) residues on whic...

Health System Reform in the United States

In 2010, the United States adopted its first-ever comprehensive set of health system reforms in the Affordable Care Act (ACA). Implementation of the law, though politically contentious and controversial, has now reached a stage where reversal of most elements of the law is no longer feasible. The controversial portions of the law that expand affordable health insurance coverage to most U.S. cit...