Abstract
Abstract Increasing atmospheric carbon dioxide (CO 2 ) concentration can increase biomass production that may influence carbon (C) dynamics in terrestrial ecosystems. Soil CO 2 efflux as affected by crop residues from high CO 2 environments managed under different tillage systems has not been explored. This study examined the effects of tillage systems in a legume [soybean [ Glycine max (L.) Merr.]] and nonlegume [grain sorghum [ Sorghum bicolor ] (L.) Moench.] CO 2 ‐enriched agroecosystem on the rates of short‐term CO 2 evolution from a Blanton loamy sand (loamy siliceous, thermic Grossarenic Paleudults). In the spring of 1994, CO 2 efflux observations initiated within 5 s after a tillage event were compared to no‐tillage conditions for 8 d in plots where both crop species had been grown in open top field chambers under two CO 2 conditions (ambient and twice ambient) for two seasons (1992 and 1993). Added CO 2 increased yields, residue, and root biomass; higher percent ground cover was also observed in CO 2 ‐enriched plots prior to the tillage treatment. Differences in C/N ratio of the residue may have influenced CO 2 efflux rates; C/N ratio was highest for sorghum and was increased by elevated CO 2 . Efflux patterns were characterized by flushes of CO 2 following initial tillage and rainfall events. Species × tillage and CO 2 × species interactions were noted on several days and for total CO 2 efflux values. Our results suggest that short‐term CO 2 fluxes may be greater for tilled soybean and for soybean grown under elevated CO 2 ; however, short‐term flux rates in the sorghum crop were affected by tillage, but not by CO 2 level. These short‐term results should be viewed with caution when predicting long‐term C turnover in agroecosystems.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. 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 11
Claim · model-written summary
Added CO2 increased soybean yields, residue and root biomass and ground cover.
- Taxon
- soybean
Glycine maxe1 - Treatment
- Added CO 2e0
- Outcome
- yields, residue, and root biomasse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Added CO 2 increased yields, residue, and root biomass; higher percent ground cover was also observed in CO 2 ‐enriched plots prior to the tillage treatment.”
e1“legume [soybean [ Glycine max (L.) Merr.]]”
Claim · model-written summary
Added CO2 increased sorghum yields, residue and root biomass.
- Taxon
- grain sorghum
Sorghum bicolore1 - Treatment
- Added CO 2e0
- Outcome
- yields, residue, and root biomasse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Added CO 2 increased yields, residue, and root biomass”
e1“grain sorghum [ Sorghum bicolor ]”
Claim · model-written summary
Sorghum residue had the highest C/N ratio.
SorghumOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“C/N ratio was highest for sorghum and was increased by elevated CO 2 .”
Claim · model-written summary
Elevated CO2 increased sorghum residue C/N ratio.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“C/N ratio was highest for sorghum and was increased by elevated CO 2 .”
Claim · model-written summary
Tillage and rain were followed by soil CO2 efflux flushes in these agroecosystems.
- Taxon
- soybeanGlycine maxe1
- Treatment
- initial tillagee0
- Outcome
- Efflux patternse0
- Direction
- flushese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Efflux patterns were characterized by flushes of CO 2 following initial tillage and rainfall events.”
e1“soybean [ Glycine max (L.) Merr.]”
Claim · model-written summary
Species and tillage interacted in several daily and total CO2 efflux measures.
- Taxon
- soybeanGlycine maxe1
- Treatment
- tillagee0
- Outcome
- total CO 2 efflux valuese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Species × tillage and CO 2 × species interactions were noted on several days and for total CO 2 efflux values.”
e1“soybean [ Glycine max (L.) Merr.]”
Claim · model-written summary
CO2 and species interacted for several daily and total soil CO2 efflux measures.
- Taxon
- grain sorghumSorghum bicolore1
- Treatment
- CO 2e0
- Outcome
- total CO 2 efflux valuese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Species × tillage and CO 2 × species interactions were noted on several days and for total CO 2 efflux values.”
e1“grain sorghum [ Sorghum bicolor ]”
Claim · model-written summary
Short-term CO2 flux may be greater for tilled soybean.
- Taxon
- soybeanGlycine maxe0
- Treatment
- tillede0
- Outcome
- short‐term CO 2 fluxese0
- Direction
- greatere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“short‐term CO 2 fluxes may be greater for tilled soybean”
Claim · model-written summary
Short-term CO2 flux may be greater for soybean grown under elevated CO2.
- Taxon
- soybeanGlycine maxe0
- Treatment
- elevated CO 2e0
- Outcome
- short‐term CO 2 fluxese0
- Direction
- greatere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“short‐term CO 2 fluxes may be greater for tilled soybean and for soybean grown under elevated CO 2”
Claim · model-written summary
Short-term sorghum flux rates were affected by tillage.
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“short‐term flux rates in the sorghum crop were affected by tillage, but not by CO 2 level.”
Claim · model-written summary
Short-term sorghum flux rates were not affected by CO2 level.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“short‐term flux rates in the sorghum crop were affected by tillage, but not by CO 2 level.”
The same questions in other papers
co2 · yield · Sorghum bicolor (sorghum)Positive and negative results
1 paper in the same direction as this paper · 2 in the opposite direction
- no effect
- negative
- positive
co2 · yield · Glycine max (soybean)Positive and negative results
85 papers in the same direction as this paper · 10 in the opposite direction
- positive
- no effect
- negative
92 papers more in this group
See all 96 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.