Author
Siemens, Mark | |
Hulick, Donald |
Submitted to: Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE)
Publication Type: Proceedings Publication Acceptance Date: 2/2/2007 Publication Date: 2/11/2007 Citation: Siemens, M.C., Hulick, D.E. 2007. Development of an alternative, reaper/flail based harvesting system for no-till farming - 2nd year. In Electronic-only Proceedings International Conference on Crop Harvesting and Processing. ASABE Publ. Number 701P0307e, 12pp. St. Joseph, MI:ASABE. 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 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 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 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 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 (graff) harvested averaged about 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 and increase the adoption of sustainable agricultural systems by optimally sizing crop residue for no-till seeding. Technical Abstract: 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 the 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 that ranged in yield from 3.3 to 6.4 t/ha. 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 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 spend, 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 awned wheat were less 1/12 that of clean grain and efficient material handling systems would need to be developed. Awnless wheat had graff densities that were 1/5 that of clean grain and therefore could be handled with commercially available equipment. |