Abstract
A two year field experiment was carried out in Delta Municipality, British Columbia. The study was designed to investigate the effects of dates of underseeding different cover crops such as crimson, red clover and alsike clovers and annual ryegrass and fall rye with sweet com. The experiment was conducted as a split plot, randomized complete block design with 12 treatment combinations and four replicates. Main plots were the two dates of cover crop planting, one shortly after emergence and the second at side dressing time (~ 30 cm). Subplots were comprised of an unseeded control plus five different cover crops seeded under sweet com. In the 1992-1993 and 1993-1994 growing seasons, the effects of cover crops on fresh arid dry cob yield of sweet com were not significant. In the 1992-1993 experiment the type of underseeded cover crops had no effect on either fresh or dry stalk yield, while in the 1993-1994 growing season stalk yields were reduced by fall rye and annual ryegrass relative to red clover. Early planting of cover crops significantly reduced the fresh and dry stalk yield of sweet com. There were no differences due to cover crops in the com ear leaf nitrogen concentration in the 1992-1993 growing season. However, in the 1993-1994 growing season, sweet com/fall rye had significantly lower ear leaf nitrogen concentrations than sweet com/red clover. In the 1993-1994 growing season the ear leaf nitrogen concentrations of early underseeded sweet com were significantly lower than ear leaf nitrogen concentration of late underseeded sweet corn. In the 1992-1993 growing season, red clover produced the highest cover crop dry matter yield. Nitrogen concentrations in alsike and red clovers were higher than that of annual ryegrass. In 1993-1994 growing season, crimson clover produced the highest dry matter yield. The nitrogen content of crimson clover was higher than that of alsike clover, fall rye and annual ryegrass in that year. In both 1992-1993 and 1993-1994 growing seasons, annual ryegrass had the highest percent cover compared to the other treatments. Fresh and dry cob yields of sweet corn were not affected by date of seeding nor type of cover crop underseeded. Early underseeded cover crop appeared to compete with sweet corn for nitrogen as compared to late underseeding. Despite low dry matter production which may be attributed to different growth habits, annual ryegrass and alsike clover look promising soil cover crops because they gave higher percentage of soil cover.
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Claims 17
Claim · model-written summary
Underseeded cover crops did not significantly change sweet corn fresh or dry cob yield in either season.
- Taxon
- sweet cornt0
- Treatment
- cover cropse0
- Outcome
- fresh arid dry cob yielde0
- Qualifier
- 1992-1993 and 1993-1994 growing seasonse0
Not reportedComparatorDirection
Verbatim
e0“In the 1992-1993 and 1993-1994 growing seasons, the effects of cover crops on fresh arid dry cob yield of sweet com were not significant.”
t0“sweet corn”
Claim · model-written summary
Cover crop type did not affect sweet corn fresh or dry stalk yield in 1992–1993.
- Taxon
- sweet cornt0
- Treatment
- underseeded cover cropse0
- Outcome
- fresh or dry stalk yielde0
- Direction
- no effecte0
- Qualifier
- 1992-1993 experimente0
Not reportedComparator
Verbatim
e0“In the 1992-1993 experiment the type of underseeded cover crops had no effect on either fresh or dry stalk yield”
t0“sweet corn”
Claim · model-written summary
Fall rye reduced sweet corn stalk yields relative to red clover in 1993–1994.
Verbatim
e0“in the 1993-1994 growing season stalk yields were reduced by fall rye and annual ryegrass relative to red clover.”
t0“sweet corn”
Claim · model-written summary
Annual ryegrass reduced sweet corn stalk yields relative to red clover in 1993–1994.
Verbatim
e0“in the 1993-1994 growing season stalk yields were reduced by fall rye and annual ryegrass relative to red clover.”
t0“sweet corn”
Claim · model-written summary
Early cover crop planting significantly reduced sweet corn fresh and dry stalk yield.
- Taxon
- sweet cornt0
- Treatment
- Early planting of cover cropse0
- Outcome
- fresh and dry stalk yielde0
- Direction
- reducede0
Not reportedComparator
Verbatim
e0“Early planting of cover crops significantly reduced the fresh and dry stalk yield of sweet com.”
t0“sweet corn”
Claim · model-written summary
Cover crops did not differ in sweet corn ear leaf nitrogen concentration in 1992–1993.
- Taxon
- sweet cornt0
- Treatment
- cover cropse0
- Outcome
- ear leaf nitrogen concentratione0
- Direction
- no differencese0
- Qualifier
- 1992-1993 growing seasone0
Not reportedComparator
Verbatim
e0“There were no differences due to cover crops in the com ear leaf nitrogen concentration in the 1992-1993 growing season.”
t0“sweet corn”
Claim · model-written summary
Fall rye underseeding lowered sweet corn ear leaf nitrogen relative to red clover in 1993–1994.
Verbatim
e0“in the 1993-1994 growing season, sweet com/fall rye had significantly lower ear leaf nitrogen concentrations than sweet com/red clover.”
t0“sweet corn”
Claim · model-written summary
Early underseeding lowered sweet corn ear leaf nitrogen concentration relative to late underseeding.
Verbatim
e0“the ear leaf nitrogen concentrations of early underseeded sweet com were significantly lower than ear leaf nitrogen concentration of late underseeded sweet corn.”
Claim · model-written summary
Red clover produced the highest cover crop dry matter yield in 1992–1993.
- Taxon
- red clover
Trifolium pratensee0 - Outcome
- cover crop dry matter yielde0
- Direction
- higheste0
- Qualifier
- 1992-1993 growing seasone0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In the 1992-1993 growing season, red clover produced the highest cover crop dry matter yield.”
Claim · model-written summary
Alsike clover nitrogen concentration exceeded annual ryegrass.
Verbatim
e0“Nitrogen concentrations in alsike and red clovers were higher than that of annual ryegrass.”
Claim · model-written summary
Red clover nitrogen concentration exceeded annual ryegrass.
- Taxon
- red cloversTrifolium pratensee0
- Outcome
- Nitrogen concentrationse0
- Direction
- highere0
- Comparator
- annual ryegrasse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nitrogen concentrations in alsike and red clovers were higher than that of annual ryegrass.”
Claim · model-written summary
Crimson clover produced the highest cover crop dry matter yield in 1993–1994.
Verbatim
e0“In 1993-1994 growing season, crimson clover produced the highest dry matter yield.”
Claim · model-written summary
Crimson clover nitrogen content exceeded alsike clover, fall rye, and annual ryegrass in 1993–1994.
Verbatim
e0“The nitrogen content of crimson clover was higher than that of alsike clover, fall rye and annual ryegrass in that year.”
Claim · model-written summary
Annual ryegrass achieved the highest percent cover in both seasons.
Verbatim
e0“In both 1992-1993 and 1993-1994 growing seasons, annual ryegrass had the highest percent cover compared to the other treatments.”
Claim · model-written summary
Early underseeded cover crops appeared to compete with sweet corn for nitrogen more than late underseeding.
- Taxon
- sweet corne0
- Interactor
- cover crope0weed
- Outcome
- compete with sweet corn for nitrogene0
- Comparator
- late underseedinge0
Not reportedDirection
Verbatim
e0“Early underseeded cover crop appeared to compete with sweet corn for nitrogen as compared to late underseeding.”
Claim · model-written summary
Annual ryegrass was recommended as a promising soil cover crop because of high soil cover.
Verbatim
e0“annual ryegrass and alsike clover look promising soil cover crops because they gave higher percentage of soil cover.”
Claim · model-written summary
Alsike clover was recommended as a promising soil cover crop because of high soil cover.
Verbatim
e0“annual ryegrass and alsike clover look promising soil cover crops because they gave higher percentage of soil cover.”
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