Table 1.
Water demand comparison between Cannabis and commodity crops
| Plants | Total growing period (days) | Water demand per season (million gallons acre−1) |
Daily water demand (gallon ft−2 day−1) |
Ref |
|---|---|---|---|---|
| Cannabis: outdoor | 150 | 1.57 a | 0.24 | (HGA, 2010) |
| Cannabis: outdoor | August | n.a | 0.22 | (Wilson et al., 2019) |
| Cannabis: outdoor | September | n.a | 0.17 | (Wilson et al., 2019) |
| Cannabis: indoor | August | n.a | 0.18 | (Wilson et al., 2019) |
| Cannabis: indoor | September | n.a | 0.22 | (Wilson et al., 2019) |
| Cotton | 180–195 | 0.75–1.39b | 0.09–0.15 | (Brouwer and Heibloem, 1986) |
| Cotton | / | / | 0.14–0.17 | (Hussain et al., 2020) |
| Maize | 130–150 | 0.53–0.86b | 0.07–0.13 | (Brouwer and Heibloem, 1986) |
| Corn | / | / | 0.22 (peak) | (Rogers et al. 2017) |
| Soybean | 135–150 | 0.48–0.75b | 0.07–0.13 | (Brouwer and Heibloem, 1986) |
| Soybean | / | / | 0.22 (peak) | (Rogers et al. 2017) |
| Wheat | 120–150 | 0.48–0.69b | 0.07–0.19 | (Brouwer and Heibloem, 1986) |
| Wheat | / | / | 0.19 (peak) | (Rogers et al. 2017) |
| Rice | 90–150 | 0.48–0.75b | 0.09–0.18 | (Brouwer and Heibloem, 1986) |
| Rice | / | / | 0.11–0.15 | (Intaboot, 2017) |
Notea: The water demand of cannabis is calculated based on 22.7 l (6 gallons) of water per day during the growing season and 200 plants per 5,000 sq. ft (HGA, 2010)
Noteb: The water demand of crops is based on crop water need from Table 14 in Brouwer Heibloem (Brouwer and Heibloem, 1986). We convert the unit from mm to million gallon acre−1 according to the rule of unit conversion where 1 acre inch is equivalent to 27,154.29 gallon