References
- Burwell , R. E. , Schuman , G. E. , Piest , R. F. , Spomer , R. G. and McCalla , T. M. 1974 . Quality of water discharged from two agricultural watersheds in S.W. . Iowa. Water Resources Research , 10 : 359 – 365 .
- Environmental Protection Agency . 1971 . “Methods for Chemical Analysis of Water and Wastes” , 312 – 312 . Washington, D.C. : U.S. Government Printing Office .
- Fish , G. R. 1969 . Lakes: Value of recent research of measure eutrophication and to indicate possible causes . Journal of Hydrology , 8 : 77 – 85 .
- Gburek , W. J. and Heald , W. R. 1974 . Soluble phosphate output of an agricultural watershed in Pennsylvania . Water Resources Research , 10 : 113 – 118 .
- Kilmer , V. J. , Gilliam , J. W. , Lutz , J. F. , Joyce , R. T. and Ekland , C. D. 1974 . Nutrient losses from a fertilized grassed watershed in western North Carolina . Journal of Environmental Quality , 3 : 214 – 219 .
- McColl , R. H. S. , White , E. and Waugh , J. R. 1975 . Chemical runoff in a catchment converted to agricultural use . N.Z. Journal of Science , 18 : 67 – 84 .
- Menzel , R. G. , Rhoades , E. D. , Olness , A. E. and Smith , S. J. 1978 . Variability of annual nutrient and sediment discharges in runoff from Oklahoma cropland and rangeland . Journal of Environmental Quality , 7 : 401 – 405 .
- Mitchell , S. F. 1971 . Phytoplankton productivity in Tomahawk Lagoon, Lake Waipori, and Lake Mahinerangi . Fisheries Research Bulletin , 3
- Murphy , J. and Riley , J. P. 1962 . A modified single solution method for the determination of phosphate in natural waters . Analytica Chimica Acta , 27 : 31 – 36 .
- O'Connor , P. W. and Syers , J. K. 1975 . Comparison of methods for the determination of total phosphorus in waters containing particulate material . Journal of Environmental Quality , 4 : 347 – 350 .
- Schuman , G. E. , Spomer , R. G. and Piest , R. F. 1973 . Phosphorus losses from four agricultural watersheds on Missouri Valley loess . Soil Science Society of America Proceedings , 32 : 424 – 427 .
- Sharpley , A. N. and Syers , J. K. 1979 . Phosphorus inputs into a stream draining an agricultural watershed. II. Amounts and relative significance of runoff types . Water, Air, and Soil Pollution , 9 (in press)
- Sharpley , A. N. , Syers , J. K. and O'Connor , P. W. 1976 . Phosphorus inputs into a stream draining an agricultural watershed. I. Sampling . Water, Air, and Soil Pollution , 6 : 39 – 52 .
- Vollenweider , R. A. 1968 . Scientific fundamentals of the eutrophication of lakes and flowing waters with particular reference to nitrogen and phosphorus . O.E.C.D. Report OAS/CSI/68.27, Paris ,