ARS | Publication request: AGRICULTURAL MANAGEMENT EFFECTS ON CROP PRODUCTION AND N LOSSES TO TILE DRAINAGE IN THE NASHUA STUDY: SIMULATION RESULTS WITH RZWQM

Submitted to: Workshop Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: April 19, 2004
Publication Date: April 20, 2004
Citation: Ma, L., Malone, R.W., Heilman, P., Anapalli, S., Ahuja, L.R., Kanwar, R.S. 2004. Agricultural management effects on crop production and n losses to tile drainage in the nashua study: simulation results with rzwqm. International Workshop on applications, enhancements and collaborations of ARS RZWQM and GPFARM. April 20-22, 2004. Fort Collins. pp. 14-15.

Interpretive Summary: Understanding the effects of agricultural management on crop production and environmental quality is important for sustainable agriculture and conservation planning. The use of system models helps quantify the management effects and develop decision support tools. This study reports simulated management effects using the ARS Root Zone Water Quality Model (RZWQM) after calibrating for a long-term experiment in Nashua, IA. The experiment was conducted at Iowa State University's Northeast Research Center. The site consists of 36 one-acre plots. Tile drains from the center tile were collected from each plot and used for water quality analysis. Three phases of study were conducted from 1977 to 1993, 1993 to 1998, and 1998-2003. Simulation results showed that plowing had no effect on yield and slightly increased N losses in tile flow. LSNT treatment showed some reduction in N loss to tile flow, but no effect on yield. Due to more fertilizer applications for continuous corn (CC) rotation, more N losses to tile flow were simulated for CC than for corn-soybean (CS) rotation. The model simulated less N loss to tile flow when manure-N was applied compared to UAN-N applications. In addition, the model simulated slightly lower yield when manure was applied.

Technical Abstract: Understanding the effects of agricultural management on crop production and environmental quality is important for sustainable agriculture and conservation planning. The use of system models helps quantify the management effects and develop decision support tools. This study reports simulated management effects using the ARS Root Zone Water Quality Model (RZWQM) after calibrating for a long-term experiment in Nashua, IA. The experiment was conducted at Iowa State University's Northeast Research Center. The site consists of 36 one-acre plots. Tile drains from the center tile were collected from each plot and used for water quality analysis. Three phases of study were conducted from 1977 to 1993, 1993 to 1998, and 1998-2003. Simulation results showed that plowing had no effect on yield and slightly increased N losses in tile flow. LSNT treatment showed some reduction in N loss to tile flow, but no effect on yield. Due to more fertilizer applications for continuous corn (CC) rotation, more N losses to tile flow were simulated for CC than for corn-soybean (CS) rotation. The model simulated less N loss to tile flow when manure-N was applied compared to UAN-N applications. In addition, the model simulated slightly lower yield when manure was applied.