|Woodson, William - Dave|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/20/1997
Publication Date: N/A
Technical Abstract: Accurate grain measurements at specific field locations are needed for site specific nutrient and pest management recommendations. This study evaluated the accuracy of one, two, and three second duration corn (Zea Mays)yield information derived from an eight-row combine equipped with a yield monitor and global positioning system (GPS). Three different methods swere used to harvest corn from a 30 by 60-m grid in a 65 ha field. Grain was harvested by the following techniques: (i) a 2-row plot combine was used to harvest grain from a 8.7 m**2 area; (ii) grain was hand harvested from 10 plants (1.4 m**2 area); and (iii) a combine-yield monitor system was used to harvest grain from 12 (1 second), 24 (2 seconds), and 36 (3 seconds) m**2 areas. The plot combine, hand collecting, and yield monitor estimates were highly correlated to each other. Spatial variability analysis showed that the eight-row Case 1660 International axial flow combine-Ag Leader 2000 yield monitor-Global Positioning system (GPS) smoothed yield information, which resulted in a yield distribution that was skewed toward larger values. The apparent skewing was caused by underestimating high yields and over estimating low yields. Bias in the yield information should be viewed carefully as misinterpretations could lead to incorrect or faulty management decisions.