Development of a Technique to Reduce Combine Header Losses in Soybeans (Part 4)

A Verification Test for Evaluating Reduction of Header Loss Using an Experimental Cutter Bar

Abstract

We measured header losses under varied experimental conditions to investigate the relationship between the forward motion of stalks during the gathering process and header losses, and optimized the dimensions of the cutter bar and the combine settings. Next, in field tests on farms, we evaluated an experimental cutter bar designed to reduce header losses The results showed header losses, shatter loss and stalk loss to be correlated to the ratio of anti-cut area, lodging angular velocity and stalk motion angle during the displacement process. We determined the conditions needed to reduce the forward motion of the stalk during the gathering process based on the center of gravity speed as calculated from lodging angular velocity, and corrected for deflection during contact between knife and stalk. The results revealed the optimal guard pitch to be 50mm, knife angle 20°, and advance ratio of 1.03. We provisionally named the experimental cutter bar a “narrow-pitch cutter bar.” Header losses during use of the narrow-pitch cutter bar were approximately half those sustained using a conventional cutter bar for soybeans with lower stem heights.