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United States Department of Agriculture

Agricultural Research Service

Title: A New Grain Harvesting System for Single Pass Grain Harvest, Biomass Collection, Crop Residue Sizing and Grain Segregation

Authors
item Siemens, Mark
item Hulick, Donald - FORMER ARS EMPLOYEE

Submitted to: Direct Seed Cropping Systems Conference
Publication Type: Proceedings
Publication Acceptance Date: December 27, 2007
Publication Date: January 23, 2008
Citation: Citation: Siemens, M.C. and D.E. Hulick. 2008. A new grain harvesting system for single pass grain harvest, biomass collection, crop residue sizing and grain segregation. In Proc. 11th Annual Direct Seed Cropping Systems Conf., pp. 12. Moscow, Idaho: Pacific Northwest Direct Seed Association.

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 quantity and rate of material harvested and biomass chopped. The regression equation generated can be used to predict power requirements for harvesting in conditions different than those used in this study. Total machine power requirements for a harvester with a 30’ header would be about 265 HP and could be supplied by readily available, low cost diesel engines. The chaff yield in the grain/chaff mixture harvested exceeded .9 ton/ac which would increase farm revenue by $18.90/ac with chaff valued at $21/ton. Certain varieties of wheat had graff densities that were 1/5 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 50 to 95 bu/ac. 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 1.1 HP/ft and only slightly higher than no-load power requirement of 0.8 HP/ft. Power requirements for harvesting, conveying and flailing ranged from a low of 2.1 to high of 5.5 HP/ft depending on travel speed, crop yield, biomass concentration, and chop height. Values were linearly correlated with the combined grain, chaff and biomass feed rate (t/h) with an R2 of 0.88. Total machine power requirements for a harvester with a 30 ft header would be about 265 HP, including 100 HP for propulsion, losses and reserve. Chaff yield in the grain/chaff (graff) mixture harvested exceeded 0.9 t/ac in six of the seven trials. With chaff valued at $21/t, collecting 0.9 t/h of chaff would increase farm revenues by about $19/ac. 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.

Last Modified: 12/20/2014
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