|Gascho, G - UNIVERSITY OF GEORGIA|
|Davis, J - COLORADO STATE UNIV.|
|Hook, J - UNIVERSITY OF GEORGIA|
Submitted to: Fluid Journal
Publication Type: Trade Journal
Publication Acceptance Date: July 19, 1999
Publication Date: July 19, 1999
Citation: GASCHO, G.J., WAUCHOPE, R.D., DAVIS, J.G., TRUMAN, C.C., DOWLER, C.C., HOOK, J.E., JOHNSON, A.W., SUMNER, H.R. SIMULATED RAIN EXPERIMENTS MEASURE RUNOFF OF N AND P.. FLUID JOURNAL. 7(3):Issue #26, 16-19(1999), Official Journal of the Fluid Fertilizer Foundation.1999. Technical Abstract: Runoff from agricultural fields is a nonpoint source of nitrogen (N) and phosphorus (P) pollution. Such nutrient losses from runoff can accelerate eutrophication of streams and lakes and enhance hypoxia. Attempts have been made to experimentally determine conditions that contribute to runoff losses. Simulated rain experiments were used to measure runoff of N and P. .Runoff was equal for two scales of plots. There were greater losses of soluble-P from the larger (6,692 sq. ft.) plots (1.25 lbs./A) than from the smaller (60 sq. ft.) plots (0.9 lbs./A). Nitrate-N losses averaged 2.4 lbs./A and bioavailable-P losses were 2.05 lbs./A. Greatest NO3-N and soluble-P losses occurred the day after application of granular fertilizer, whereas bioavailable-P loss was greatest at days 14 and 19. No increase in NO3-N losses was found one day after application of urea-anhydrous ammonia, possibly indicating that liquid fertilizers are not as susceptible to runoff losses as granular fertilizers. Results of this study should encourage the use of small plots, thereby saving research time and expense, plus provide useful data for estimating losses at similar sites.