Abstract
Abstract Narrow row spacing (<76 cm) could improve crop competitiveness, suppress weeds and might provide yield advantage. Many studies have been conducted to evaluate the impact of narrow row spacing; however, no quantitative synthesis of these studies exists. The objectives of this meta-analysis were to (1) quantify the overall effect of narrow row spacing (<76 cm) on weed density, biomass, control, weed seed production, and yield in corn ( Zea mays L.) and soybean [ Glycine max (L.) Merr.] compared with 76-cm row spacing, and (2) assess the influence of agronomic management decisions (tillage type, weed management, herbicide application frequency and time) on effect of narrow row spacing on weed suppression and corn and soybean yield. We compiled 1,904 pair-wise observations from 35 studies conducted in 12 states in the United States during 1961 to 2018. Averaged across individual observations, narrow row spacing suppressed weed density by 34%, weed biomass by 55%, and weed seed production by 45%, while it improved weed control by 32% and crop yield by 11% compared with 76-cm row spacing. Narrow row spacing in soybean suppressed weed density by 42%, weed biomass by 71%, and increased crop yield by 12% compared with 76-cm row spacing. Although narrow row spacing had a nonsignificant effect on response variables in corn, the number of studies ( n = 1 to 6) and observations ( n = 1 to 59) addressing each response variable were limited. Tillage type (conventional and reduced) did not influence the response of weed density, control, and seed production in narrow row spacing; however, weed biomass and weed seed production were more greatly reduced with the sequential application of herbicides compared with a single application. Thus, narrow row spacing in soybean can be integrated with other options for management of herbicide-resistant weeds.
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Claims 13
Claim · model-written summary
Narrow spacing reduced pooled weed density by 34%.
- Taxon
- corn
Zea mays subsp. mayst0 - Treatment
- narrow row spacinge0
- Outcome
- weed densitye0
- Direction
- suppressede0
- Value
- 34%e0
- Comparator
- 76-cm row spacinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“narrow row spacing suppressed weed density by 34%, weed biomass by 55%, and weed seed production by 45%, while it improved weed control by 32% and crop yield by 11% compared with 76-cm row spacing.”
t0“corn and soybean”
Claim · model-written summary
Narrow spacing reduced pooled weed biomass by 55%.
- Taxon
- soybean
Glycine maxt0 - Treatment
- narrow row spacinge0
- Outcome
- weed biomasse0
- Direction
- suppressede0
- Value
- 55%e0
- Comparator
- 76-cm row spacinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“narrow row spacing suppressed weed density by 34%, weed biomass by 55%, and weed seed production by 45%, while it improved weed control by 32% and crop yield by 11% compared with 76-cm row spacing.”
t0“corn and soybean”
Claim · model-written summary
Narrow spacing reduced pooled weed seed production by 45%.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- narrow row spacinge0
- Outcome
- weed seed productione0
- Direction
- suppressede0
- Value
- 45%e0
- Comparator
- 76-cm row spacinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“narrow row spacing suppressed weed density by 34%, weed biomass by 55%, and weed seed production by 45%, while it improved weed control by 32% and crop yield by 11% compared with 76-cm row spacing.”
t0“corn and soybean”
Claim · model-written summary
Narrow spacing improved pooled weed control by 32%.
- Taxon
- soybeanGlycine maxt0
- Treatment
- narrow row spacinge0
- Outcome
- weed controle0
- Direction
- improvede0
- Value
- 32%e0
- Comparator
- 76-cm row spacinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“narrow row spacing suppressed weed density by 34%, weed biomass by 55%, and weed seed production by 45%, while it improved weed control by 32% and crop yield by 11% compared with 76-cm row spacing.”
t0“corn and soybean”
Claim · model-written summary
Narrow spacing improved pooled crop yield by 11%.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- narrow row spacinge0
- Outcome
- crop yielde0
- Direction
- improvede0
- Value
- 11%e0
- Comparator
- 76-cm row spacinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“narrow row spacing suppressed weed density by 34%, weed biomass by 55%, and weed seed production by 45%, while it improved weed control by 32% and crop yield by 11% compared with 76-cm row spacing.”
t0“corn and soybean”
Claim · model-written summary
Narrow soybean rows suppressed weed density by 42%.
- Taxon
- soybeanGlycine maxe0
- Treatment
- Narrow row spacinge0
- Outcome
- weed densitye0
- Direction
- suppressede0
- Value
- 42%e0
- Comparator
- 76-cm row spacinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Narrow row spacing in soybean suppressed weed density by 42%, weed biomass by 71%, and increased crop yield by 12% compared with 76-cm row spacing.”
Claim · model-written summary
Narrow soybean rows suppressed weed biomass by 71%.
- Taxon
- soybeanGlycine maxe0
- Treatment
- Narrow row spacinge0
- Outcome
- weed biomasse0
- Direction
- suppressede0
- Value
- 71%e0
- Comparator
- 76-cm row spacinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Narrow row spacing in soybean suppressed weed density by 42%, weed biomass by 71%, and increased crop yield by 12% compared with 76-cm row spacing.”
Claim · model-written summary
Narrow soybean rows increased yield by 12%.
- Taxon
- soybeanGlycine maxe0
- Treatment
- Narrow row spacinge0
- Outcome
- crop yielde0
- Direction
- increasede0
- Value
- 12%e0
- Comparator
- 76-cm row spacinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Narrow row spacing in soybean suppressed weed density by 42%, weed biomass by 71%, and increased crop yield by 12% compared with 76-cm row spacing.”
Claim · model-written summary
Narrow spacing effects in corn were nonsignificant, with few studies and observations.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- narrow row spacinge0
- Outcome
- response variablese0
- Qualifier
- limitede0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Although narrow row spacing had a nonsignificant effect on response variables in corn, the number of studies ( n = 1 to 6) and observations ( n = 1 to 59) addressing each response variable were limited.”
Claim · model-written summary
Tillage type did not influence narrow-row effects on weed density, control or seed production.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- Tillage type (conventional and reduced)e0
- Outcome
- response of weed density, control, and seed productione0
- Direction
- did not influencee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Tillage type (conventional and reduced) did not influence the response of weed density, control, and seed production in narrow row spacing”
t0“corn and soybean”
Claim · model-written summary
Sequential herbicide application reduced weed biomass more than a single application.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- sequential application of herbicidese0
- Outcome
- weed biomasse0
- Direction
- more greatly reducede0
- Comparator
- single applicatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“weed biomass and weed seed production were more greatly reduced with the sequential application of herbicides compared with a single application.”
t0“corn and soybean”
Claim · model-written summary
Sequential herbicide application reduced weed seed production more than a single application.
- Taxon
- soybeanGlycine maxt0
- Treatment
- sequential application of herbicidese0
- Outcome
- weed seed productione0
- Direction
- more greatly reducede0
- Comparator
- single applicatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“weed biomass and weed seed production were more greatly reduced with the sequential application of herbicides compared with a single application.”
t0“corn and soybean”
Claim · model-written summary
The authors suggest integrating narrow soybean rows with other resistant-weed management options.
- Taxon
- soybeanGlycine maxe0
- Outcome
- management of herbicide-resistant weedse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“narrow row spacing in soybean can be integrated with other options for management of herbicide-resistant weeds.”
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See all 658 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.