CALIBRATION OF ADAPT AND SWAT MODELS FOR FIELD-SCALEWATER QUALITY RESPONSE TO MANAGEMENT PRACTICES

摘要

Field losses of sediment, nutrients, and pesticides can be reduced through careful management of land cover,tillage, and application practices. This study will present calibrations of ADAPT (Agricultural Drainage And PesticideTransport) and SWAT (Soil and Water Assessment Tool) using field scale runoff, sediment, nutrient, and pesticide data.Models were applied to a 12-ha field site with 15 separate terraces having 3 replications of 5 integrated agriculturalmanagement system (IAMS) treatments. Each terrace was monitored for runoff and runoff water quality during 1999, 2000and 2001. The five IAMS treatments included two full-width tillage treatments: (1) surface-broadcast N and P, shallowpreplant incorporated (PP/I) herbicides; (2) deep-banded N and P, preemergence broadcast (PE/B) herbicides; and three no till treatments: (3) early spring broadcast N and P, PE/B herbicide; (4) deep-banded N and P, PE/B herbicide; and (5) starterfertilizer application at planting time with surface broadcast N, PE/B herbicide. ADAPT is a field scale model that allowsmanagement of timing and placement of nutrient and pesticide, whereas SWAT consists of sub-basin and routingcomponents; however many model features are common to both. Predicted concentrations of runoff, sediment, N, P, atrazineand S-metolachlor will be compared to measured concentration from multiple site-years of data. The highest losses generallywere recorded in 1999 and 2000 when fertilizers or pesticides were surface applied to a tilled soil. However, losses werereduced considerably with PP/I. These models are expected to predict similar trends when actual field level conditions areused for simulation.