Modification of a Self - Propelled Rotary Mower for Wheat Forage Harvest

Many field experiments require the collection of forage yields in addition to grain yield (small grains). ln smal! plot research, mechanized grain harvest is common. However, forage harvest is often accomplished by hand which is time consuming and labor intensive. Sample heterogeneity increases when forage harvest is obtained by hand. The objectives of this study were to construct a mechanized forage harvester that would simplify the harvesting process while providing a homogenous sample and to determine forage yield reduction associated with using the harvester compared to hand clipping at the soil surface. A John Deere GT262 self propelled rotary mower was modified to be used for small plot wheat forage harvesting. Field trials were established at two locations to determine the yield reduction associated with using the forage harvester versus hand clipping at the soil surface. Significant differences in yield were found at both locations. The mean dry matter yield averaged over two years and two Iocations obtained using the harvester was 63.1% of that obtained by hand clipping at the soil surface during growth stages Feekes 6 and Feekes 10. Total N in wheat forage collected was significantly different using the harvester versus hand clipping. This is partially explained by decreased N in the lower stems at later stages of reproductive growth. The design of the harvester makes it possible to harvest several plots in a short amount of time while also allowing a larger area to be harvested which increases experimental accuracy and sample homogeneity. When the efficiency of the forage harvester (0.631) is used as a correction factor, the difference between the estimated and actual amounts of forage present is S 4o/" of the total forage present (Feekes 6 through Feekes 10).