Paper · 2026 · cIRcle (University of British Columbia)

Efficacy of under-vine and alleyway cover crops across distinct microclimates in the Okanagan Valley, British Columbia

Yearley, Jamie

12
claims
23
verbatim quotes
0
citations
5
research areas
✓
Open access · cc-by-nc-nd

Abstract

Cover crops (CCs) provide many services to the agroecosystem. The efficacy of CCs varies by species composition and site-specific conditions. This study compared CC mixtures in two growth zones: the under-vine areas and alleyways, at two irrigated organic vineyards in the Okanagan Valley, British Columbia, Canada. The vineyards varied in climate and soil texture. Mixtures were compared with respect to weed suppression, biomass production, and N and C input potential. The effects of CCs on vineyard productivity, and fruit quality were assessed. Three alleyway and three under-vine CC mixtures were sown in May 2021 and reseeded in 2022. Alleyway treatments included mixtures composed of a grass and legume species; one mixture included tillage radish. Under-vine treatments included two legume monocultures, and one mixture composed of a grass with a legume. Large variation was observed between sites and years due to soil texture, environmental conditions, and disease/pest pressure. Overall, CC biomass production was positively associated with both weed suppression and CC aboveground N content. Alleyway mixtures containing perennial clover species, especially when paired with tillage radish, produced larger CC biomass, had greater CC N contents and superior weed suppression than the CC mixtures containing a cool-season annual legume. Under-vine CCs performed differently between sites. At Site 1, the perennial clover monoculture outperformed other treatments. At Site 2 in 2022, the grass and legume mixture was the most productive CC. The phenology of CC species, driven by genetic makeup, played a large role in both establishment and stand persistence under regional conditions. Perennial grasses and legumes, which were able to recover after mowing and resist traffic, demonstrated superior weed suppression, especially when paired with a companion crop such as tillage radish. No differences among CC mixtures were observed in grape yield, or fruit quality, indicating that CCs exerted minimal competitive pressure on vines. This study indicates that perennial legumes, when paired with a perennial grass, are well suited for use as CCs in irrigated Okanagan vineyards. Further research is needed to clarify how these cover crop mixtures interact with vineyard irrigation regimes, and how they compare to grower standard practices.

Abstract from the paper’s OpenAlex record; open copy licensed cc-by-nc-nd. 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 12

Associationobservedoriginal resultpositivemeasured

Claim · model-written summary

Cover crop biomass was positively associated with weed suppression and aboveground nitrogen content.

Taxon
vineyardst0
Material
CCe0
Outcome
weed suppression and CC aboveground N contente0
Direction
positively associatede0

Verbatim

e0

“CC biomass production was positively associated with both weed suppression and CC aboveground N content”

✓ located verbatim in the source · abstract, characters 1000–1103 · show in text ↑
t0

“two irrigated organic vineyards in the Okanagan Valley”

✓ located verbatim in the source · abstract, characters 234–288 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Alleyway mixtures containing perennial clover, especially with tillage radish, produced more biomass than mixtures containing a cool-season annual legume.

Taxon
vineyardst0
Treatment
Alleyway mixtures containing perennial clover species, especially when paired with tillage radishe0
Outcome
CC biomasse0
Direction
largere0
Comparator
CC mixtures containing a cool-season annual legumee0

Verbatim

e0

“Alleyway mixtures containing perennial clover species, especially when paired with tillage radish, produced larger CC biomass, had greater CC N contents and superior weed suppression than the CC mixtures containing a cool-season annual legume”

✓ located verbatim in the source · abstract, characters 1105–1347 · show in text ↑
t0

“two irrigated organic vineyards in the Okanagan Valley”

✓ located verbatim in the source · abstract, characters 234–288 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

The perennial clover alleyway mixtures had greater cover crop nitrogen content than the cool-season annual legume mixtures.

Taxon
vineyardst0
Treatment
Alleyway mixtures containing perennial clover species, especially when paired with tillage radishe0
Outcome
CC N contentse0
Direction
greatere0
Comparator
CC mixtures containing a cool-season annual legumee0

Verbatim

e0

“Alleyway mixtures containing perennial clover species, especially when paired with tillage radish, produced larger CC biomass, had greater CC N contents and superior weed suppression than the CC mixtures containing a cool-season annual legume”

✓ located verbatim in the source · abstract, characters 1105–1347 · show in text ↑
t0

“two irrigated organic vineyards in the Okanagan Valley”

✓ located verbatim in the source · abstract, characters 234–288 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

The perennial clover alleyway mixtures suppressed weeds more than cool-season annual legume mixtures.

Taxon
vineyardst0
Treatment
Alleyway mixtures containing perennial clover species, especially when paired with tillage radishe0
Outcome
weed suppressione0
Direction
superiore0
Comparator
CC mixtures containing a cool-season annual legumee0

Verbatim

e0

“Alleyway mixtures containing perennial clover species, especially when paired with tillage radish, produced larger CC biomass, had greater CC N contents and superior weed suppression than the CC mixtures containing a cool-season annual legume”

✓ located verbatim in the source · abstract, characters 1105–1347 · show in text ↑
t0

“two irrigated organic vineyards in the Okanagan Valley”

✓ located verbatim in the source · abstract, characters 234–288 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

Under-vine cover crops performed differently between sites.

Taxon
vineyardst0
Outcome
performed differently between sitese0

Verbatim

e0

“Under-vine CCs performed differently between sites.”

✓ located verbatim in the source · abstract, characters 1349–1400 · show in text ↑
t0

“two irrigated organic vineyards in the Okanagan Valley”

✓ located verbatim in the source · abstract, characters 234–288 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

At Site 1, the perennial clover monoculture outperformed other treatments.

Taxon
vineyardst0
Treatment
perennial clover monoculturee0
Outcome
outperformede0
Direction
outperformede0
Comparator
other treatmentse0
Setting
Site 1e0

Verbatim

e0

“At Site 1, the perennial clover monoculture outperformed other treatments.”

✓ located verbatim in the source · abstract, characters 1401–1475 · show in text ↑
t0

“two irrigated organic vineyards in the Okanagan Valley”

✓ located verbatim in the source · abstract, characters 234–288 · show in text ↑
Observationobservedoriginal resultpositivemeasured

Claim · model-written summary

At Site 2 in 2022, the grass and legume mixture was the most productive cover crop.

Taxon
vineyardst0
Material
grass and legume mixturee0
Outcome
most productive CCe0
Direction
most productivee0
Setting
Site 2e0

Verbatim

e0

“At Site 2 in 2022, the grass and legume mixture was the most productive CC.”

✓ located verbatim in the source · abstract, characters 1476–1551 · show in text ↑
t0

“two irrigated organic vineyards in the Okanagan Valley”

✓ located verbatim in the source · abstract, characters 234–288 · show in text ↑
Associationobservedoriginal resultmeasured

Claim · model-written summary

Cover crop phenology played a large role in establishment and stand persistence under regional conditions.

Taxon
vineyardst0
Organ / stage
phenologye0
Outcome
establishment and stand persistencee0
Qualifier
under regional conditionse0

Not reportedDirection

Verbatim

e0

“The phenology of CC species, driven by genetic makeup, played a large role in both establishment and stand persistence under regional conditions.”

✓ located verbatim in the source · abstract, characters 1552–1697 · show in text ↑
t0

“two irrigated organic vineyards in the Okanagan Valley”

✓ located verbatim in the source · abstract, characters 234–288 · show in text ↑
Observationobservedoriginal resultpositivemeasured

Claim · model-written summary

Perennial grasses and legumes that recovered after mowing and resisted traffic showed superior weed suppression, especially with tillage radish.

Taxon
vineyardst0
Material
Perennial grasses and legumese0
Outcome
weed suppressione0
Direction
superiore0
Qualifier
especially when paired with a companion crop such as tillage radishe0

Verbatim

e0

“Perennial grasses and legumes, which were able to recover after mowing and resist traffic, demonstrated superior weed suppression, especially when paired with a companion crop such as tillage radish.”

✓ located verbatim in the source · abstract, characters 1698–1897 · show in text ↑
t0

“two irrigated organic vineyards in the Okanagan Valley”

✓ located verbatim in the source · abstract, characters 234–288 · show in text ↑
Intervention effectobservedoriginal resultno effectmeasured

Claim · model-written summary

Grape yield did not differ among cover crop mixtures.

Taxon
vineyardst0
Treatment
CC mixturese0
Outcome
grape yielde0
Direction
No differencese0
Comparator
among CC mixturese0

Verbatim

e0

“No differences among CC mixtures were observed in grape yield, or fruit quality”

✓ located verbatim in the source · abstract, characters 1898–1977 · show in text ↑
t0

“two irrigated organic vineyards in the Okanagan Valley”

✓ located verbatim in the source · abstract, characters 234–288 · show in text ↑
Intervention effectobservedoriginal resultno effectmeasured

Claim · model-written summary

Fruit quality did not differ among cover crop mixtures.

Taxon
vineyardst0
Treatment
CC mixturese0
Outcome
fruit qualitye0
Direction
No differencese0
Comparator
among CC mixturese0

Verbatim

e0

“No differences among CC mixtures were observed in grape yield, or fruit quality”

✓ located verbatim in the source · abstract, characters 1898–1977 · show in text ↑
t0

“two irrigated organic vineyards in the Okanagan Valley”

✓ located verbatim in the source · abstract, characters 234–288 · show in text ↑
Recommendationauthor interpretationoriginal resultbasis n/a

Claim · model-written summary

The authors recommend perennial legumes paired with a perennial grass as cover crops for irrigated Okanagan vineyards.

Taxon
vineyardse0
Outcome
perennial legumes, when paired with a perennial grass, are well suited for use as CCse0
Setting
Okanagane0

Verbatim

e0

“perennial legumes, when paired with a perennial grass, are well suited for use as CCs in irrigated Okanagan vineyards”

✓ located verbatim in the source · abstract, characters 2072–2189 · show in text ↑