Monitoring and predicting manure application rates using precision conservation technology

ABSTRACT:

A side-discharge manure spreader was retrofitted with precision conservation technology. Lateral patterns and swath widths remained relatively constant with peaks in lateral application rates (kg ha⁻¹) at 4 to 6 m (13 to 20 ft) (liquid manure) and at 2 to 7 m (7 to 23 ft) and 20 to 25 m (66 to 82 ft) (solid manure) from the spreader. A “dump zone” of thicker manure application occurred for the initial 0 to 6 m of travel (liquid manure). The minimum scale of precision that can be achieved realistically with this type of equipment depends on the swath width. Results suggest that nitrogen (N) is less manageable than soil phosphorus levels and organic matter by simply retrofitting side-discharge spreaders with precision technology. Lateral pattern of measured application rate was fitted to a three-parameter function using the gamma (1) distribution. Regression of measured liquid manure application rates samples against predicted rates was significant (R² > 0.80; p < 0.01). The average accuracy of predicted values was ±10 percent, excluding one outlier.