Paper · 2025 · Agrosystems Geosciences & Environment

Floral hemp biomass and cannabinoid yield response to moisture stress under irrigation in a semi‐arid climate

Richard J. Roseberg; Jake Hoyman; Govinda Shrestha

9
claims
9
verbatim quotes
1
citations
2
research areas
✓
Open access · cc-by-nc-nd

Abstract

Abstract Hemp ( Cannabis sativa L .) was re‐legalized as an agricultural crop through the USDA 2018 Farm Bill, but cropping guidelines remain limited, especially for floral hemp grown for cannabinoid extraction. In this study, the response of direct‐seeded, field‐grown autoflower and full‐season hemp cultivars to varying rates of applied irrigation was compared over multiple years in a semi‐arid environment. Measurements included floral and total biomass, cannabinoid concentration, and cannabinoid yield. The primary flower size did not vary much regardless of irrigation amount, even for plants grown with no supplemental irrigation. As irrigation increased from very low levels up to 100% of the location's potential evapotranspiration (PEt) and beyond, leaf and stem biomass continued to increase as the plants also got taller. Secondary and tertiary flower biomass increased with irrigation, but only up to about 80% of PEt. Above that amount, floral biomass typically plateaued for both autoflower and full‐season types. Floral cannabinoid concentrations did not vary much regardless of irrigation amount. Irrigating at rates greater than about 80% of PEt does not generally increase cannabinoid yield. In contrast, under very dry conditions hemp can grow, reach maturity, and produce some flowers and associated cannabinoid yield even when receiving little or no rainfall or irrigation. Thus, growing hemp with low, moderate, or no irrigation in a semi‐arid climate may be economically feasible (despite the lower yield) in certain situations, depending on costs of irrigation water, other crop management decisions, and market valuation of end products.

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 9

Intervention effectobservedoriginal resultno effectmeasured

Claim · model-written summary

Primary hemp flower size varied little across irrigation amounts.

Treatment
irrigation amounte0
Outcome
primary flower sizee0
Direction
did not vary muche0
Comparator
no supplemental irrigatione0

Not reportedTaxon

Verbatim

e0

“The primary flower size did not vary much regardless of irrigation amount, even for plants grown with no supplemental irrigation.”

✓ located verbatim in the source · abstract, characters 510–639 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Leaf and stem biomass increased as irrigation rose to and beyond 100% PEt.

Treatment
irrigatione0
Outcome
leaf and stem biomasse0
Direction
increasee0
Value
100%e0
Comparator
very low levelse0

Not reportedTaxon

Verbatim

e0

“As irrigation increased from very low levels up to 100% of the location's potential evapotranspiration (PEt) and beyond, leaf and stem biomass continued to increase as the plants also got taller.”

✓ located verbatim in the source · abstract, characters 640–835 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Plant height increased with irrigation.

Treatment
irrigatione0
Outcome
tallere0
Direction
tallere0
Comparator
very low levelse0

Not reportedTaxon

Verbatim

e0

“As irrigation increased from very low levels up to 100% of the location's potential evapotranspiration (PEt) and beyond, leaf and stem biomass continued to increase as the plants also got taller.”

✓ located verbatim in the source · abstract, characters 640–835 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

Secondary and tertiary flower biomass increased with irrigation to about 80% PEt.

Treatment
irrigatione0
Outcome
Secondary and tertiary flower biomasse0
Direction
increasede0
Value
about 80% of PEte0

Not reportedTaxonComparator

Verbatim

e0

“Secondary and tertiary flower biomass increased with irrigation, but only up to about 80% of PEt.”

✓ located verbatim in the source · abstract, characters 836–933 · show in text ↑
Intervention effectobservedoriginal resultno effectmeasured

Claim · model-written summary

Floral biomass plateaued above about 80% PEt for both cultivar types.

Treatment
Above that amounte0
Outcome
floral biomasse0
Direction
plateauede0

Not reportedTaxonComparator

Verbatim

e0

“Above that amount, floral biomass typically plateaued for both autoflower and full‐season types.”

✓ located verbatim in the source · abstract, characters 934–1030 · show in text ↑
Intervention effectobservedoriginal resultno effectmeasured

Claim · model-written summary

Floral cannabinoid concentrations varied little across irrigation amounts.

Treatment
irrigation amounte0
Outcome
Floral cannabinoid concentrationse0
Direction
did not vary muche0

Not reportedTaxonComparator

Verbatim

e0

“Floral cannabinoid concentrations did not vary much regardless of irrigation amount.”

✓ located verbatim in the source · abstract, characters 1031–1115 · show in text ↑
Intervention effectobservedoriginal resultno effectmeasured

Claim · model-written summary

Irrigation above about 80% PEt generally did not increase cannabinoid yield.

Treatment
rates greater than about 80% of PEte0
Outcome
cannabinoid yielde0
Direction
does not generally increasee0

Not reportedTaxonComparator

Verbatim

e0

“Irrigating at rates greater than about 80% of PEt does not generally increase cannabinoid yield.”

✓ located verbatim in the source · abstract, characters 1116–1212 · show in text ↑
Observationobservedoriginal resultpositivemeasured

Claim · model-written summary

Hemp matured and produced some flowers and cannabinoid yield with little or no rain or irrigation.

Outcome
produce some flowers and associated cannabinoid yielde0
Qualifier
little or no rainfall or irrigatione0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Cannabis sativa subsp. sativa
Cannabis sativa subsp. sativa · TaxonNo machine-readable author provided. Bastique assumed (based on copyright claims). · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

e0

“under very dry conditions hemp can grow, reach maturity, and produce some flowers and associated cannabinoid yield even when receiving little or no rainfall or irrigation.”

✓ located verbatim in the source · abstract, characters 1226–1397 · show in text ↑
Recommendationauthor interpretationoriginal resultbasis n/a

Claim · model-written summary

Low, moderate or no irrigation may be economically feasible in some semi-arid settings.

Outcome
growing hemp with low, moderate, or no irrigatione0
Qualifier
in certain situationse0
Setting
semi‐arid climatee0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Cannabis sativa subsp. sativa
Cannabis sativa subsp. sativa · TaxonNo machine-readable author provided. Bastique assumed (based on copyright claims). · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

e0

“growing hemp with low, moderate, or no irrigation in a semi‐arid climate may be economically feasible (despite the lower yield) in certain situations, depending on costs of irrigation water, other crop management decisions, and market valuation of end products.”

✓ located verbatim in the source · abstract, characters 1404–1665 · show in text ↑

irrigation · growth · Cannabis sativaPositive and negative results

3 papers: 2 positive, 1 negative or no effect

1 paper in the same direction as this paper · 1 in the opposite direction

  1. negative
  2. positive
See all 3 papers →

irrigation · molecular: metabolites · Cannabis sativaPositive and negative results

3 papers: 2 positive, 1 negative or no effect

2 in the opposite direction

  1. positive
  2. positive
See all 3 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.