10,000 litres per ethanol? ISMA study questions popular water use claim
An ISMA-ICAR backed study challenges long-held beliefs about sugarcane’s water usage, calling it more efficient than key grain crops. The findings could reshape the ethanol debate, shifting focus from crop choice to irrigation practices.
- May 5, 2026,
- Updated May 5, 2026 2:40 PM IST
A fresh industry-backed study is attempting to reset one of the most contentious debates around India’s ethanol push: how much water does sugarcane really consume?
The report, a collaboration between the Indian Sugar & Bio-energy Manufacturers Association (ISMA) and ICAR institutes, argues that the widely circulated claims about sugarcane’s excessive water footprint are overstated and in some cases, misleading.
The big claim: Sugarcane is more water efficient than grains
MUST READ: Ethanol debate: Industry pushes back on ‘10,000 litre’ water claim
At the heart of the study is a comparison between sugarcane and competing crops like rice, wheat, and maize. The findings suggest that producing one kilogram of sugarcane requires about 173 litres of water under conventional farming, and as little as 114 litres when drip irrigation is used.
By contrast, rice and wheat can require up to 2,244 litres per kilogram, while maize needs over 1,600 litres.
The implication is significant. If these numbers hold, sugarcane is not the water guzzler it is often portrayed to be. Instead, it may be among the more water-efficient biomass crops when measured per unit of output.
Ethanol debate
The report also enters the politically sensitive debate around ethanol production. Critics have argued that producing one litre of ethanol can consume upwards of 10,000 litres of water.
MUST READ: Is India heading towards 100% ethanol for motor vehicles?
The ISMA-ICAR study sharply contests this. It estimates that sugarcane-based ethanol requires about 2,469 litres of water per litre under traditional irrigation, and roughly 1,634 litres with drip systems.
That is significantly lower than maize-based ethanol, which the study pegs at around 4,500 litres per litre.
In effect, the industry is making a clear case: sugarcane is not just viable, but the most water-efficient feedstock available for India’s ethanol blending programme.
The real issue: How sugarcane is grown
The report shifts the focus from the crop itself to cultivation practices. Traditional flood irrigation, still widely used in India, leads to substantial water losses through evaporation and runoff.
In contrast, drip irrigation reduces water use by 15–25% and improves yields at the same time.
Field trials cited in the study show sugarcane yields rising from around 102 tonnes per hectare under conventional practices to about 126 tonnes under drip irrigation.
This reframes the debate. The problem, the study suggests, is not sugarcane per se—but inefficient irrigation methods.
Why this matters now
The timing of the report is critical. India is aggressively pushing ethanol blending in petrol to reduce oil imports, and sugarcane is the backbone of that strategy.
At the same time, concerns over groundwater depletion especially in states like Maharashtra and Uttar Pradesh have put sugarcane under scrutiny.
This study is effectively a counter-narrative from the industry, backed by multi-location trials across tropical and subtropical regions of India.
A fresh industry-backed study is attempting to reset one of the most contentious debates around India’s ethanol push: how much water does sugarcane really consume?
The report, a collaboration between the Indian Sugar & Bio-energy Manufacturers Association (ISMA) and ICAR institutes, argues that the widely circulated claims about sugarcane’s excessive water footprint are overstated and in some cases, misleading.
The big claim: Sugarcane is more water efficient than grains
MUST READ: Ethanol debate: Industry pushes back on ‘10,000 litre’ water claim
At the heart of the study is a comparison between sugarcane and competing crops like rice, wheat, and maize. The findings suggest that producing one kilogram of sugarcane requires about 173 litres of water under conventional farming, and as little as 114 litres when drip irrigation is used.
By contrast, rice and wheat can require up to 2,244 litres per kilogram, while maize needs over 1,600 litres.
The implication is significant. If these numbers hold, sugarcane is not the water guzzler it is often portrayed to be. Instead, it may be among the more water-efficient biomass crops when measured per unit of output.
Ethanol debate
The report also enters the politically sensitive debate around ethanol production. Critics have argued that producing one litre of ethanol can consume upwards of 10,000 litres of water.
MUST READ: Is India heading towards 100% ethanol for motor vehicles?
The ISMA-ICAR study sharply contests this. It estimates that sugarcane-based ethanol requires about 2,469 litres of water per litre under traditional irrigation, and roughly 1,634 litres with drip systems.
That is significantly lower than maize-based ethanol, which the study pegs at around 4,500 litres per litre.
In effect, the industry is making a clear case: sugarcane is not just viable, but the most water-efficient feedstock available for India’s ethanol blending programme.
The real issue: How sugarcane is grown
The report shifts the focus from the crop itself to cultivation practices. Traditional flood irrigation, still widely used in India, leads to substantial water losses through evaporation and runoff.
In contrast, drip irrigation reduces water use by 15–25% and improves yields at the same time.
Field trials cited in the study show sugarcane yields rising from around 102 tonnes per hectare under conventional practices to about 126 tonnes under drip irrigation.
This reframes the debate. The problem, the study suggests, is not sugarcane per se—but inefficient irrigation methods.
Why this matters now
The timing of the report is critical. India is aggressively pushing ethanol blending in petrol to reduce oil imports, and sugarcane is the backbone of that strategy.
At the same time, concerns over groundwater depletion especially in states like Maharashtra and Uttar Pradesh have put sugarcane under scrutiny.
This study is effectively a counter-narrative from the industry, backed by multi-location trials across tropical and subtropical regions of India.