Skip to main content
ARS Home » Pacific West Area » Pendleton, Oregon » Columbia Plateau Conservation Research Center » Research » Publications at this Location » Publication #220579
Title: A New Grain Harvesting System for Single-Pass Grain Harvest, Biomass Collection, Crop Residue Sizing, and Grain Segregation

Author
item Siemens, Mark
item HULICK, DONALD - FORMER ARS EMPLOYEE

Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/16/2008
Publication Date: 9/30/2008
Citation: Siemens, M.C., Hulick, D.E. 2008. A New Grain Harvesting System for Single-Pass Grain Harvest, Biomass Collection, Crop Residue Sizing, and Grain Segregation. Trans. ASABE 51(5): 1519-1527.

Interpretive Summary: Although modern combines are tremendous machines that harvest the crop and separate grain from crop residues, they are expensive ($250,000) and not ideally suited for collection of biomass or for conservation tillage systems where crop residue is left on the soil surface. To overcome these limitations, a harvesting system is introduced that combines existing technologies in a unique way to improve cereal grain harvest performance, profitability and flexibility. 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 header to harvest the crop and a flail to chop the standing residue into small pieces. A prototype harvester was fabricated to determine performance characteristics in terms of machine power requirements, quantity of biomass collected and bulk density of the material harvested. Machine power requirements were linearly correlated with harvesting speed and concentration of biomass. Total machine power requirements for a harvester with a 24’ header would be about 240 HP and could be supplied by readily available, low cost diesel engines. The chaff yield in the grain/chaff mixture harvested exceeded 2 ton/ac which would increase farm revenue by $18.62/ac with chaff valued at $9.31/ton. Certain varieties of wheat had graff densities that were 1/4 that of clean grain and therefore could be handled with commercially available equipment. This research showed that the simpler, lower cost harvesting system introduced is technically feasible and has the potential to lower production cost, increase farm revenues, sustainably collect biomass and increase the adoption of sustainable agricultural systems by optimally sizing crop residue for no-till seeding.

Technical Abstract: A cereal grain harvesting system is introduced that combines existing technologies in a unique way to improve cereal grain harvest performance, profitability and efficiently collect biomass. 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 winnow the grain, 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 reaper/flail harvester was fabricated to determine system design criteria and performance characteristics in terms of machine power requirements, quantity of biomass collected and bulk density of the material harvested. Trials were conducted in seven wheat (Triticum aestivum L.) fields in Oregon during 2005 and 2006 that ranged in yield from 3.3 to 6.4 t/ha. Harvester performance was evaluated at various travel speeds, straw chop heights and with different types of wheat. Flail power requirements were linearly correlated with quantity and rate of biomass chopped with an R2 of 0.91. Maximum stripper header requirement was 2.7 kW/m and only slightly higher than no-load power requirement of 1.9 kW/m. Power requirements for harvesting, conveying and flailing ranged from a low of 5.0 to high of 13.5 kW/m depending on travel speed, crop yield, biomass concentration, and chop height. 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. Chaff yield in the grain/chaff (graff) mixture harvested exceeded 2.0 t/ha in six 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 awned wheat were less than about 1/11 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.