Development of an alternative, reaper/flail based harvesting system for biomass collection and no-till seeding - 2^nd year

A harvesting system is introduced that combines existing technologies in a unique way to simplify harvesting equipment, lower production costs and improve grain quality consistency. The harvesting system is comprised of three machines - one to gather the crop and prepare the residue for no-till seeding, a second to thresh and clean the crop, and a third to separate the grain by density/quality. The crop-gathering machine consists of a power unit equipped with a stripper header to harvest the crop and a flail to chop the standing residue into small pieces. A prototype harvester was fabricated to determine system design criteria and performance characteristics in terms of machine power requirements and bulk density of the material harvested. Trials were conducted in seven wheat fields during 2005 and 2006 that ranged in yield from 3.3 to 6.4 t/ha. In this paper, only power requirements for 2005 are reported. Flail power requirements ranged from 3 to 11 kW/m depending on harvesting speed and concentration of biomass. Flail power requirements were linearly correlated with biomass feed rate (t/h) with an R² of 0.87. Stripper header power requirements ranged from 2.0 kW/m to 2.7 kW/m, only slightly higher than the no-load power requirement of 1.9 kW/m. Total harvester power requirements for harvesting, conveying and flailing ranged from 5.7 kW/m to 13.5 kW/m depending on travel speed, wheat yield and quantity of straw chopped. Total machine power requirements for a harvester with a 7.3 m header would be about 175kW, including 75 kW for propulsion, losses and reserve. The chaff yield in the grain/chaff mixture (graff) harvested ranged from 2.0 to 2.5 t/ha for five of the seven trials. With chaff valued at $23/t, collecting 2 t/h of chaff would increase farm revenues by $46/ha. Realistic graff densities of owned wheat were less than about 1/12 that of clean grain and new, efficient material handling systems would need to be developed to have harvesting capacities comparable to that of a conventional combine based system. Awnless wheat had graff densities that averaged about 1/5 that of clean grain. Equipment is commercially available to handle this volume of material and have harvesting field capacities comparable to that of a conventional combine based system.