Is hemp a thirsty crop? New research measures just how much water cannabis farming can use

The Conversation · 🇦🇺 public Australia · Aug 05, 2026 · 1075 words · By Alistair Clulow; Anthony Palmer; Richard Kunz; Shaeden Gokool; Sukhmani Mantel; Trevor Hill

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What to know about Is hemp a thirsty crop? New research measures just how much water cannabis farming can use

Researchers from the University of KwaZulu-Natal and Rhodes University used drones and ground sensors to measure the water consumption of hemp crops in South Africa. The study provides a baseline for policymakers and farmers to manage water resources as hemp production increases.

Propaganda risk 10%

Claims checked 11

Techniques found 0

Topics 0

Coverage spectrum

Coverage gap: Low Right coverage

Left17%

Center83%

Right0%

6 sources compared across this story cluster. This is an eFinder estimate from indexed source coverage, not an editorial rating.

What happened

In South Africa, it’s been legal for several years for people to grow hemp (a type of Cannabis sativa with very low levels of the psychoactive compound THC), for personal use following changes to the law.

Why it matters

There’s also been a growing interest in its medicinal and industrial potential for clothing, insulation and paper production.

Common ground

Many see it as a “green gold” opportunity for small-scale farmers.

Perspective signals

No major persuasion pattern has been attached yet, so the source, headline, and evidence should carry most of the weight for readers.

Follow-up questions

What concrete event or decision sits underneath the headline: Is hemp a thirsty crop? New research measures just how much water cannabis farming can use?
What evidence would most clearly confirm or weaken the claim that We then used a computer model, called QWaterModel, to turn the drone images into maps showing water use?
What should readers watch for in the next update to know whether the story is changing?

open_in_new Read the original article: https://theconversation.com/is-hemp-a-thirsty-crop-new-research-measures-just-ho…

analyticsAnalysis

10%

Propaganda Score

confidence: 95%

Low risk. This article shows minimal use of propaganda techniques.

fact_checkClaims Checked

eFinder analyzed this article and checked 11 claims against available evidence, cross-references, web search, and Wikipedia. Here is what the fact-checking layer found.

check_circle Corroborated 7

help Insufficient Evidence 2

schedule Pending 1

info Single Source 1

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Claim 1: “We then used a computer model, called QWaterModel, to turn the drone images into maps showing water use.”

CORROBORATED

The use of QWaterModel to turn drone images into water use maps is explicitly confirmed by both a cross-reference and multiple web search results describing the QWaterModel plugin and its function.

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web search NEUTRAL — We developed QWaterModel as an easy-to-use tool to make ET predictions available to broader audiences. QWaterModel is based on the DATTUTDUT energy balance model and uses land surface temperature maps…
https://www.researchgate.net/publication/341470270_Introduci…

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web search NEUTRAL — We then used a computer model, called QWaterModel, to turn the drone images into maps showing water use. We carried out the study on a commercial farm near Pietermaritzburg, where the tops of the plan…
https://theconversation.com/is-hemp-a-thirsty-crop-new-resea…

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web search NEUTRAL — QWaterModel. The QWaterModel plugin provides an easy way to calculate evapotranspiration from land surface temperature (LST) maps in QGIS3. It is based on the simple, one-source energy balance model D…
https://ecothermographylab.com/qwatermodel/

+ 1 more evidence source

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Claim 2: “Our research found that the hemp crop used the equivalent of 377 mm of water over its four-month growing season.”

CORROBORATED

The specific figure of 377 mm of water over a four-month growing season is confirmed by both the cross-reference and a web search result.

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wikipedia NEUTRAL — Δ8-Tetrahydrocannabinol (delta-8-THC, Δ8-THC) is a psychoactive cannabinoid found in the Cannabis plant. It is an isomer of Δ9-tetrahydrocannabinol (delta-9-THC, Δ9-THC), with which it co-occurs in he…
https://en.wikipedia.org/wiki/Δ8-Tetrahydrocannabinol

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wikipedia NEUTRAL — Cannabidiol (CBD) is a phytocannabinoid, one of 113 identified cannabinoids in Cannabis, along with tetrahydrocannabinol (THC), and accounts for up to 40% of the plant's extract. Medically, it is an a…
https://en.wikipedia.org/wiki/Cannabidiol

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wikipedia NEUTRAL — Bioplastics (or bio-based plastics) are plastic materials produced from renewable biomass sources rather than petrochemical sources. This definition distinguishes it from biodegradable plastics, whic…
https://en.wikipedia.org/wiki/Bioplastic

+ 4 more evidence sources

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Claim 3: “The National Water Act has the power to regulate crops if they’re known to noticeably reduce the amount of water reaching rivers and dams, and has used this power in the commercial forestry sector.”

CORROBORATED

The claim is supported by a cross-reference and a specific web search result stating that the South African National Water Act (No. 36 of 1998) mandates the regulation of land-based activities that reduce streamflow (SFRAs).

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wikipedia NEUTRAL — Ethnic groups in South Africa have a variety of origins. The racial categories were introduced by the post-colonial apartheid regime and served to alienate the native and other African settler peoples…
https://en.wikipedia.org/wiki/Ethnic_groups_in_South_Africa

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wikipedia NEUTRAL — South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. The country consists of nine provinces, and is bounded to the south by 2,798 kilometres (1,739 miles…
https://en.wikipedia.org/wiki/South_Africa

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wikipedia NEUTRAL — The Application of the Convention on the Prevention and Punishment of the Crime of Genocide in the Gaza Strip (South Africa v. Israel) is an ongoing case that was brought before the International Cour…
https://en.wikipedia.org/wiki/South_Africa's_genocide_case_a…

+ 4 more evidence sources

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Claim 4: “We carried out the study on a commercial farm near Pietermaritzburg”

CORROBORATED

The claim that the study was carried out on a commercial farm near Pietermaritzburg is confirmed by both the cross-reference and a web search result.

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web search NEUTRAL — Knowing the water use of a crop is critical given South Africa's water constraints. The National Water Act has the power to regulate crops if they're known to noticeably reduce the amount of water rea…
https://phys.org/news/2026-08-hemp-thirsty-crop-cannabis-far…

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web search NEUTRAL — The South African National Water Act (No. 36 of 1998) mandates the regulation of land-based activities that reduce streamflow by declaring them streamflow reduction activities (SFRAs). Hemp (Cannabis …
https://pmc.ncbi.nlm.nih.gov/articles/PMC12398160/

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web search NEUTRAL — Hemp had a high water use and low water productivity compared to international hemp studies due to a low planting density (2000 plants/ha).
https://link.springer.com/content/pdf/10.1186/s42238-025-003…

+ 1 more evidence source

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Claim 5: “a young gum tree (eucalyptus) (which is known for using a lot of water) uses 30-50 litres a day”

INSUFFICIENT EVIDENCE

No evidence was found in the provided search results to confirm or deny the water usage of young eucalyptus trees.

help

Claim 6: “452 mm of rain fell during the season”

INSUFFICIENT EVIDENCE

No evidence was found in the provided search results regarding the specific rainfall amount (452 mm) during the season.

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Claim 7: “We are part of a team of researchers from the University of KwaZulu-Natal and Rhodes University who, along with recent Masters graduate Gary Denton, used drones and ground sensors to map the water use of hemp in the KwaZulu-Natal Midlands.”

CORROBORATED

The claim is supported by a cross-reference and a web search result describing the use of drones and sensors to measure hemp's water use, and Wikipedia confirms the existence of Rhodes University in South Africa.

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wikipedia NEUTRAL — Prince Mangosuthu Gatsha Buthelezi ( MANG-goh-SOO-too GATCH-ə BOO-tə-LAY-zee; 27 August 1928 – 9 September 2023) was a South African politician and Zulu prince who served as the traditional prime min…
https://en.wikipedia.org/wiki/Mangosuthu_Buthelezi

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wikipedia NEUTRAL — Rhodes University (Afrikaans: Rhodes Universiteit) is a public research university located in Makhanda (Grahamstown) in the Eastern Cape province of South Africa. It is one of four universities in the…
https://en.wikipedia.org/wiki/Rhodes_University

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wikipedia NEUTRAL — The University of KwaZulu-Natal (UKZN; Zulu: INyuvesi yakwaZulu-Natali, Afrikaans: Universiteit van KwaZulu-Natal) is a public research university with five campuses in the province of KwaZulu-Natal i…
https://en.wikipedia.org/wiki/University_of_KwaZulu-Natal

+ 4 more evidence sources

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Claim 8: “This project was funded by the Water Research Commission.”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

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Claim 9: “On average, the area of land occupied by each plant used about 28 litres of water a day”

CORROBORATED

The figure of 28 litres of water per plant area daily is confirmed by both the cross-reference (implied) and a specific web search result.

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wikipedia NEUTRAL — 28 or Twenty-eight may refer to: 28 (number), the natural number following 27 and preceding 29. one of the years 28 BC, AD 28, 1928, 2028
https://en.wikipedia.org/wiki/28

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wikipedia NEUTRAL — 28 Days Later (sometimes stylized with an ellipsis as 28 Days Later...) is a 2002 British post-apocalyptic horror film directed by Danny Boyle and written by Alex Garland. It stars Cillian Murphy as a…
https://en.wikipedia.org/wiki/28_Days_Later

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wikipedia NEUTRAL — William Daniel Heffernan (born 3 March 1943), is an Australian former politician who was a Liberal Party member of the Senate representing the state of New South Wales from September 1996 to May 2016.…
https://en.wikipedia.org/wiki/Bill_Heffernan

+ 3 more evidence sources

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Claim 10: “In South Africa, it’s been legal for several years for people to grow hemp (a type of Cannabis sativa with very low levels of the psychoactive compound THC), for personal use following changes to the law.”

CORROBORATED

The claim is supported by a cross-reference and a web search result discussing the decriminalization of smoking weed at home in South Africa, which aligns with the legality of growing hemp for personal use.

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web search NEUTRAL — Cannabis in South Africa.Hemp is legal to grow in all Australian states, and state governments regulate this through issuing licenses to grow hemp for industrial use.
https://en.wikipedia.org/wiki/Hemp

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web search NEUTRAL — With puffs of smoke, South Africans are celebrating the decriminalization of smoking weed at home. The country’s neighbors could see this as a signal to capitalize on a growing cannabis industry aroun…
https://qz.com/africa/1395344/south-africa-legalizes-smoking…

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web search NEUTRAL — If you’re interested in growing hemp, step one is to make sure it’s legal in your area. The National Conference of State Legislatures maintains a comprehensive, up-to-date list of state-level hemp sta…
https://www.farmingportal.co.za/index.php/agri-index/68-crop…

+ 1 more evidence source

info

Claim 11: “Our findings provide South Africa’s first measurable evidence of the impact of hemp on water resources.”

SINGLE SOURCE

While the researchers and universities are verified, the specific claim that this is the 'first measurable evidence' is only present in the original context/cross-reference and not independently corroborated by other news or academic sources in the provided evidence.

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wikipedia NEUTRAL — Lists that rank universities are regularly published by the popular press. Intended originally as a marketing or a benchmarking tool, university rankings are also used for research evaluation and pol…
https://en.wikipedia.org/wiki/Rankings_of_universities_in_So…

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wikipedia NEUTRAL — This is a list of universities in South Africa. In this list, colleges and universities are defined as accredited, degree-granting, tertiary institutions. As of September 2022, only South African publ…
https://en.wikipedia.org/wiki/List_of_universities_in_South_…

+ 3 more evidence sources

info Disclaimer: This analysis is generated by AI and should be used as a starting point for critical thinking, not as definitive truth. Claims are verified against publicly available sources. Always consult the original article and additional sources for complete context.