PRECISION AGRICULTURE AS APPLIED TO NORTH AMERICAN HAY AND FORAGE PRODUCTION

Abstract

This research developed systems to measure mass-flow of hay and forage using a self-propelledwindrower, self-propelled forage harvester and large square baler in order to generate yield mapsof hay and forage production.<br><br>The windrower was used to collect mass-flow and yield data in alfalfa using system to measure:(1) impact force at the swath forming shield; (2) crop volumetric flow past the swath formingshield; (3) conditioning roll speed; (4) platform pitch; and (5) pressure of platform drive motor.Some sensors systems were promising but even the most promising will require further evaluationbecause the average absolute mass-flow prediction error and 90th percentile error were 13.4 and26.4%, respectively, above the desired maximum of 5 and 10%.<br><br>The forage harvester was used to collect mass-flow and yield data in wilted alfalfa and wholeplantcorn silage using systems to measure: (1) feedroll displacement; (2) crop impact force in thespout; (3) blower speed; and (4) depth of material in the spout. The accuracy of these sensors wasmuch better in whole-plant corn silage than in wilted alfalfa, primarily because the former fedmuch more uniformly. The average absolute and 90th percentile errors were 12.3 and 24.2%,respectively, for wilted alfalfa, and 4.4 and 7.4%, respectively, for whole-plant corn silage.<br><br>The large square baler was used to collect mass-flow and yield data in dry alfalfa using sensorsystems to measure: (1) bale velocity; and (2) dynamic bale weight on the chute. The balevelocity and weight measurement systems were excellent at predicting mass-flow with typicalabsolute and 90th percentile errors of 1.4 and 3.2%, respectively.<br><br>Multi-parameter regression models were developed to predict mass-flow for each of the threemachines. These models were then used to create yield maps using the output from selectedsensors. The resolution of the yield maps was a function of the width of the harvested strip. Theresolution of the yield maps was the best with the windrower and forage harvester in whole- plantcorn silage because these machines had the narrowest harvesting widths. The map resolution wasless with the forage harvester harvesting wilted alfalfa and with the large square baler becausemultiple windrows were often merged together to meet the capacity needs of the machines. Thedeveloped yield maps were quite capable of showing spatial differences in yield that correspondedvery well to differences in elevation, soil type, traffic patterns and fertility. The hay and foragemass-flow sensor systems and yield mapping systems should become a valuable precision farmingtool.