Abstract
A two-year rotation of summer fallow (SF)/winter wheat (WW) is the most common cropping system in low precipitation areas of the U.S. Pacific Northwest (PNW). In SF, multiple tillage operations are used to manage weeds and maximize soil water storage and potential WW yield. Reduced tillage fallow (RTF) is an alternative to SF that leaves >30% of the previous crop's residue on the surface. A four-year (2014-18) field study was conducted to evaluate the influence of SF and RTF on weed species density, cover and composition in dryland WW; determine if changes in these weed infestation attributes have any influence on crop density and yield; and evaluate economic costs of each type of fallow management. The experimental design was randomized complete block with four replications where each phase of SF/WW and RTF/WW rotations was present every year. Individual plots of WW were divided into a weedy sub-plot with no weed control, general area with chemical weed control, and weed-free sub-plot where weeds were manually removed. Infestations of annual grass and other weeds in weedy sub-plots increased throughout the study. Grass weed cover, consisting mainly of downy brome (Bromus tectorum L.), and total weed cover were significantly lower in WW following RTF than following SF in all years except 2018. Densities of grass and total weeds were similar in both fallow managements indicating that weed plants were larger in WW following SF than following RTF due to earlier or faster emergence. Grass cover differences were not found in general areas likely because of a reduced seedbank. When weeds were present, mean yield of WW was higher following RTF than SF indicating that weeds were less competitive in RTF. Reduced tillage fallow could improve weed management in fallow/WW cropping systems of the PNW compared to SF/WW, particularly if the most problematic species are grasses.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 5
Claim · model-written summary
Annual grass and other weed infestations increased over the study.
- Taxon
- winter wheat
Triticum aestivume1 - Interactor
- annual grass and other weedse0weed
- Outcome
- Infestations of annual grass and other weedse0
- Direction
- increasede0
- Setting
- weedy sub-plotse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Infestations of annual grass and other weeds in weedy sub-plots increased throughout the study.”
e1“winter wheat (WW)”
Claim · model-written summary
Grass weed cover was lower after reduced tillage fallow except in 2018.
- Taxon
- WWe0
- Treatment
- RTFe0
- Interactor
- downy brome (Bromus tectorum L.)
Bromus tectorume0weed - Outcome
- Grass weed covere0
- Direction
- lowere0
- Qualifier
- in all years except 2018e0
- Comparator
- SFe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grass weed cover, consisting mainly of downy brome (Bromus tectorum L.), and total weed cover were significantly lower in WW following RTF than following SF in all years except 2018.”
Claim · model-written summary
Total weed cover was lower after reduced tillage fallow except in 2018.
Verbatim
e0“Grass weed cover, consisting mainly of downy brome (Bromus tectorum L.), and total weed cover were significantly lower in WW following RTF than following SF in all years except 2018.”
Claim · model-written summary
Grass and total weed densities were similar under the two fallow systems.
- Taxon
- winter wheatTriticum aestivume1
- Treatment
- both fallow managementse0
- Interactor
- weedse0weed
- Outcome
- Densities of grass and total weedse0
- Direction
- similare0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Densities of grass and total weeds were similar in both fallow managements”
e1“summer fallow (SF)/winter wheat (WW)”
Claim · model-written summary
With weeds present, wheat yield was higher after reduced tillage fallow.
Verbatim
e0“When weeds were present, mean yield of WW was higher following RTF than SF”
The same questions in other papers
rotation · weed · Triticum aestivum (wheat)Positive and negative results
17 papers in the same direction as this paper · 19 in the opposite direction
- positive
- positive
- positive
33 papers more in this group
See all 37 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.