The April rains bring May flowers, and the dry months bring a shower of misinformation about the cannabis garden. Having lost sight of public opinion and legislation, water use is the last front in the war of prohibitionists on cannabis production.
His statement is based on a false report made about a decade ago that says every plant needs six to 20 liters per day to grow, a gross exaggeration. This was based on growing the plants as large as possible during the peak water use at the highest heat. Most people grow medium plants and use less water during early growth and in cooler climates. Using so much water on a continuous basis will provoke the power of the roots and kill the plants. Somehow, the researchers forgot to mention all that and the media turned up on a spectacular exaggeration.
Let’s get real here. Qualified gardeners mitigate the use of water using compost tea, mulch and other preservation techniques. Experienced growers know that cannabis plants use less water in their vegetative cycle and more during flowering, not the same amount throughout the year. For example, a garden we followed last year used just under a gallon per plant – per week – from mid to late June, from a quarter a week to mid-spring, with no expectation of using more half a gallon. per day even at its peak of flowering (at a rate of three liters, twice a week).
Each medium-sized plant ultimately produces from a quarter to three-quarters of a pound per year, about 120 to 350 grams or (32 to 100 ounces), at a higher yield and water efficiency than tomatoes growing nearby. But what in a home garden, then, does that mean a larger-scale economy?
Cannabis is “not particularly thirsty” as a culture
A team of researchers affiliated with the University of California, Berkeley and with the State of California, the North Coast Water Quality Control Board decided to test this question. They evaluated irrigation patterns among licensed cannabis farms in northern California.
Their research confirmed that licensed outdoor marijuana farms do not put excessive strain on limited water resources, according to data published in the Journal of Environmental Management. In fact, it consumes only a fraction of the water used by other commercial crops.
The authors stated that cannabis farming is not “particularly thirsty compared to other crops.” They estimated that “outdoor legal [cannabis] The crop uses about the same amount of water as a crop as tomatoes, ”and about 33 times less water than almonds.
More water efficient than commercial wine, almonds, avocado
The results of the study are contrary to previous claims that cannabis farming put excessive pressure on the state’s limited water supply. However, there are many data to support the claims of water efficiency.
A 2020 report from New Frontier Data in partnership with Resource Innovation Institute and the University of California, Berkeley, concluded that “while the state’s trees use nearly 7 million acre-feet of water, and the rice fields using nearly 5 million acre-feet, the state’s lucrative cannabis industry uses only 3,000 acres-feet, making it the most economical crop for water among the state’s highest-yielding crops.
Swami Chaitanya is a Northern California cannabis grower and operator of Swami Select. He calculated water consumption for cannabis as an agricultural crop, using one-eighth of an ounce of dried flowers, about 3.5 grams, as a typical serving for marijuana. “Every octane requires 1,875 liters of water,” noting that “It has been widely reported that the production of a pound of meat requires at least 1,500 liters of water. The wine uses between 180 and 400 liters per bottle. they need one gallon per nut or about 100 gallons per cane, broccoli takes about five gallons per head and avocados about 75 gallons per pound.
“Another way to look at thirst is to consider how much produce is produced from a single gallon of water,” said Natalynne DeLapp, executive director of the Humboldt County Alliance of Farmers. “For other crops such as tomatoes, lettuce or almonds, a gallon of water produces between one-tenth of a hundred to two cents of value in yield. For cannabis, a gallon of water produces a value of almost $ 7. In that sense, cannabis is by far the most water-efficient agricultural product in California. ”
And the illegal cultivation operations?
Experience and data show that domestic crops and commercial cannabis crops are both relatively effective users of water, but what about underground growers?
Because the UC Berkeley study assessed only water use among legally licensed farms, the authors warned that their findings may not be applicable to illicit growth practices. Illegal operators around California are often accused of water diversion, but their actual impact on water supply is not well documented.
One thing that seems clear, though, is that encouraging legal operators and retail law enforcement slows down the flow and ultimately cuts the tap on the criminal market by cutting out its customer base. It’s also another fact that prohibitionists don’t want to hear.
Full text of the study, “Water storage and irrigation practices for cannabis guide seasonal patterns of water extraction and use in northern California,” appears in the Journal of Environmental Management.