Author
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Lenssen, Andrew |
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Submitted to: Agronomy Society of America, Crop Science Society of America, Soil Science Society of America Meeting
Publication Type: Abstract Only Publication Acceptance Date: 8/8/2007 Publication Date: 11/1/2007 Citation: Lenssen, A.W. 2007. Land rolling increases broadleaf weed emergence. In: Proceedings of Agronomy Society of America, Crop Science Society of America, Soil Science Society of America Meeting, November 4-8, 2007, New Orleans, Louisiana. Paper no. 152-4. Interpretive Summary: Annual forage and pulse crops typically are land rolled in the northern Great Plains to push exposed rocks back into the soil to prevent damage to harvest equipment. Commercial grain drills are routinely equipped with packer wheels to enhance soil-crop seed contact, resulting in more uniform crop emergence and maturity. A field trial was conducted to determine if land rolling results in increased weed emergence due to improved soil-weed seed contact. The experiment was conducted with two planting dates of pea and barley each of two years. Summer fallow plots also were included, and all treatments followed preplant tillage with a field cultivator. Land rolling doubled early season emergence and densities at harvest of tumble mustard, Russian thistle, kochia, and redroot pigweed. Total weed biomass also was doubled by rolling. However, density of wild oat was not influenced by rolling. Rolling decreased pea yield by 4.5 bushels acre-1, but did not influence soil water or water use. Land rolling is a nonchemical, cultural technique that can be used to decrease broadleaf weed seed bank in an annual forage crop such as hay barley, but in field pea, rolling may increase density of broadleaf weeds. Technical Abstract: In the northern Great Plains, annual forage and pulse crops typically are land rolled after planting to push rocks back into the soil to prevent damage to harvest equipment. Packer wheels commonly are used at planting to improve soil-seed contact for more uniform crop emergence and subsequent maturity. A field trial was conducted to determine if land rolling, analogous to using a large packer wheel, influenced density or biomass of weeds associated with field pea, forage barley, or summer fallow. The experiment included two planting dates each of two years of barley, and pea. Preplant tillage was done with a field cultivator for all treatments. Across years, crops, and planting dates, land rolling approximately doubled early season emergence and densities at harvest of tumble mustard, Russian thistle, kochia, and redroot pigweed. At harvest, rolling resulted in a doubling of total weed biomass. Wild oat densities were not influenced by rolling. Rolling decreased pea yield by 300 kg ha-1, but did not influence soil water or water use. Land rolling can be used to decrease broadleaf weed seed bank in an annual forage crop, but may increase problematic broadleaf weeds in pea. |
