Author
LIEBMAN, MATT - Iowa State University | |
MILLER, ZACHARIAH - Montana State University | |
WILLIAMS, CAROL - University Of Wisconsin | |
WESTERMAN, PAULA - University Of Rostock | |
DIXON, PHILIP - Iowa State University | |
HEGGENSTALLER, ANDREW - Dupont Pioneer Hi-Bred | |
Davis, Adam | |
MENALLED, FABIAN - Montana State University | |
SUNDBERG, DAVID - Iowa State University |
Submitted to: Weed Research
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/6/2013 Publication Date: 1/3/2014 Citation: Liebman, M., Miller, Z., Williams, C., Westerman, P., Dixon, P., Heggenstaller, A., Davis, A.S., Menalled, F., Sundberg, D. 2014. Fates of Setaria faberi and Abutilon theophrasti seeds in three crop rotation systems. Weed Research. DOI: 10.1111/wre.12069. Interpretive Summary: Understanding the fate of weed seeds in and on the soil may aid the development of weed management strategies that are less reliant upon herbicides. Previous studies have shown reductions in weed seedbanks due to crop rotation, but the impacts of different rotation systems on weed seedbank population dynamics remain poorly understood. We conducted an experiment in Iowa, USA, to determine the fates of giant foxtail and velvetleaf seeds in 2-year, 3-year, and 4-year crop rotation systems when seed additions to the soil seedbank were restricted to a single pulse at the initiation of the study. After 41 months, seed densities dropped >85% for giant foxtail and >65% for velvetleaf, but no effect of crop rotation on seedbank decline was detected. Most of the reductions in seedbank densities took place from autumn through early spring in the first five months following seed deposition, before seedling emergence occurred, suggesting that seed predation and/or seed decay were important. For giant foxtail, total cumulative seedling emergence and total seed mortality did not differ among rotation systems. In contrast, for velvetleaf, seedling emergence was 71% lower and seed mortality was 83% greater in the 3-year and 4-year rotation systems than in the 2-year system. Results of this study indicate that diversification of cropping systems through extended rotations can contribute to the management of certain weed species, such as velvetleaf, through the regulation of life history processes associated with soil seedbanks. Technical Abstract: Weed seeds in and on the soil are the primary cause of weed infestations in arable fields. Previous studies have documented reductions in weed seedbanks due to cropping system diversification through extended rotation sequences, but the impacts of different rotation systems on additions to and losses from weed seedbanks remain poorly understood. We conducted an experiment in Iowa, USA, to determine the fates of Setaria faberi and Abutilon theophrasti seeds in 2-year, 3-year, and 4-year crop rotation systems when seed additions to the soil seedbank were restricted to a single pulse at the initiation of the study. After 41 months, seed densities dropped >85% for S. faberi and >65% for A. theophrasti, but differences among rotation systems in the magnitude of seedbank reductions were not detected. Most of the reductions in seedbank densities took place from autumn through early spring in the first five months following seed deposition, before seedling emergence occurred, suggesting that seed predation and/or seed decay were important. For S. faberi, total cumulative seedling emergence and total seed mortality did not differ among rotation systems. In contrast, for A. theophrasti, seedling emergence was 71% lower and seed mortality was 83% greater in the 3-year and 4-year rotation systems than in the 2-year system. Results of this study indicate that diversification of cropping systems through extended rotations can contribute to the management of certain weed species, such as A. theophrasti, through the regulation of life history processes associated with soil seedbanks. |