| Few studies have comprehensively examined nutrient losses in runoff from furrow-irrigated fields, but the rising cost of fertilizer and finite nature of the resource encourages further research. A 2-yr experiment measured runoff losses of sediment, particulate P and N, and dissolved NO3-N, NH4-N, K, and reactive P (DRP) from fertilized, manured, or non-amended fields. Average nutrient losses were substantial, including 15.6 lbs ac/yr dissolved N, P, and K and 73.6 lbs ac/yr particulate N and P. The cost or replacing these nutrients with inorganic fertilizers was not trivial, at $54.69 ac/yr. Relative to non-amended soil, manure increased dissolved K, NO3-N, and DRP in runoff by 2.1x, 1.5x, and 2.7x, respectively. Other experiments evaluated the... |
