Cotton is a thirsty plant! Really?

NEW RESEARCH POINTS IN ANOTHER DIRECTION

The common narrative is that growing cotton devours huge amounts of water, many thousands of litres of water would be needed to produce a t-shirt. This image of cotton as a ‘thirsty’ plant has been greatly exaggerated, according to a new study published in march 2025.

According to a study published in march 2025 all stories about the huge water consumption in cotton farming can go straight into the bin. The research was conducted by Dr. Keshav Kranthi, scientific leader of the Washington-based International Cotton Advisory Committee. According to Kranthi, the water consumption of cotton is in line with the agricultural land used for cultivation.

Kranthi told the English magazine Ecotextile News that he set up the study because of the story that has been circulating for years that 10,000-20,000 litres of water are needed to grow a kilo of cotton. Experts have previously pointed out that such general assumptions are difficult to make because cotton is grown in a variety of conditions: in different geographical zones with different climates, soil types, farming methods and amounts of natural rainfall. To take all these factors into account, Kranthi therefore had to conduct a wide-ranging study. For five years (from January 2020 to January 2025), 271 sites in 38 countries were monitored daily to determine how much water fell on the cotton fields, how much was irrigated and how much water the plant released back to the outside air through evaporation. To produce a kilo of cotton lint, according to his calculation, an average of 8987 litres was needed. However, 6,500 litres of that was supplied in the form of natural rainfall, so the average irrigation requirement was 2346 litres.

Previous studies by Dutch ‘water professor’ Arjen Hoekstra and others, calculated that cotton cultivation accounts for about 2.6% of global water use. Kranthi arrives at a similar result, 2.76%. ‘This is consistent with land use, as cotton cultivation occupies about 2.92% of the total agricultural area for annual plants,’ Kranthi writes in his report. Like all other agricultural crops, cotton needs water, but the story that cotton is an extremely ‘thirsty’ plant is not true, according to these insights. Kranthi: ‘Additionally, 56,0% of global cotton acreage (17,48 million hectares) is rainfed, with zero irrigation, contributing to more than 45.0% (11.04 million tonnes of lint) of the total cotton production (24,53 million tonnes), further countering the "thirsty crop" misconception.' 

Kranthi is not the first to come to this conclusion. A few years ago, the ‘Bremer Baumwolbörse’ also pointed out that cotton really is a drought-loving plant. The relationship between cotton cultivation and the desertification of certain regions (the most famous case being the drying up of the Aral Sea) also proved to be incorrect. Nowadays, old-fashioned Soviet-era farming methods are also pointed to, while the cultivation of alfalfa in the region is also said to have played a major role. On the other hand, a Textile Exchange study (from 2014) has also been criticised for claiming that organic cotton cultivation uses 90 per cent less water than conventional cultivation. While this is true, it is also a distorted view because organic cotton is grown mainly in areas where it rains sufficiently anyway.

Cultivation is expected to take even less water in the future. The oldest irrigation method, surface irrigation, where a field is more or less flooded, is still used in many areas. It is expected that this will give way to more modern forms that involve very metered irrigation (e.g. drip irrigation) and also better monitoring of field conditions through drones. Kranthi: ‘Rainfall is a natural process over which we have no control. The focus should therefore be on practical, water-saving irrigation strategies that can be controlled by humans. Emphasis should be placed on rainwater harvesting and conservation while applying irrigation more efficiently to support more sustainable cotton production.’

A side note that may need to be made is that Dr. Kranthi's report is not, to our knowledge, peer reviewed, i.e. not critically examined by scientists in the profession. The report can be downloaded here:

Keshav R. Kranthi, Water footprint in cotton 2020-2024: a global analysis