Precision Agriculture: Zone Delineation and Water Quality Benefits. (S04-derby397585-poster)
Authors:
N.E. Derby* - North Dakota State Univ.
F.X.M. Casey - North Dakota State Univ.
D.P.V. Ralston - North Dakota State Univ.
D.W. Franzen - North Dakota State Univ.
Abstract:
Two different methods for delineation of management zones for precision agriculture were used on a 17-ha randomized complete block (RCB) plot area located within a 64-ha irrigated corn field in southeastern North Dakota in 2001. Zones were determined by 1) visual inspection of a bare soil aerial image and 2) cluster analysis of soil EC, topography, and historical yield map data. Two-thirds of the plots received nitrogen (urea) using variable rate, based on soil N variability and variable corn yield goals for the two zoning methods. One-third of the plots received uniform N application without regard to zones. The remainder of the 64-ha field was managed by the farmer-cooperator with N application based on a 12.5 Mg ha-1 yield goal. In 2002, the average N application rate and yield was 9 and 17 percent higher for the farmer-managed area versus the variable rate plot area, respectively. Lysimeters and wells were used to compare leachate and groundwater quality under precision agriculture and farmer-managed practices. The average groundwater nitrate-N concentration in the study area for 2001-2002 was 5.0 mg L-1 versus 12.6 mg L-1 under farmer management. Average lysimeter leachate nitrate-N concentrations were 7.5 mg L-1 and 50.8 mg L-1, and the mass of N lost due to leaching was 26.2 mg-1 and 99.2 mg L-1 for study versus farmer managed, respectively.
Speaker Information: Nathan Derby, North Dakota State Univ., Dept. of Soil Science 114 Walster Hall PO Box 56, Fargo, ND 58105-5638; Phone: 701-231-7555; E-mail: [email protected]
Session Information: Tuesday, November 4, 2003, 2:00 PM-4:00 PM Presentation Start: 2:00 PM (Poster Board Number: 1031)