November 15, 2023

Water Intensive Crops

Water intensive crops are often grown in preference to crops that use less water as water intensive crops will yield a higher value product. Two of the three most water intensive edible crops in Australia are sugarcane and almonds. The sugarcane crop in Australia was worth $1.33 billion in 2022 while the almond crop was worth $800 million. It takes on average 210 L of water to produce 1 kg of sugarcane. Almond farming is even more water intensive than sugarcane production. The global average water footprint to produce a single almond is 12 L of water.

Food staples (such as corn, rice, soy and wheat) also consume a lot of water due to the  large volumes that are grown. Of these, rice and wheat are the most water intensive and are often grown in water stressed regions. A kilogram of paddy rice requires 2,500 L of water to grow. Rice is currently grown in regions facing extreme water stress such as Chad and the Indus Valley. Wheat requires slightly less water than rice to grow with 1 kg of wheat requiring 1,000 L of water however more wheat is produced globally than rice with 791 million tonnes of wheat being produced annually compared with 518 million tonnes of rice.



Water Intensive Food Production

Dairy products, such as milk, cheese and yoghurt, as well as meat products also require a lot of water to produce. 1 kg of beef requires between 5,000 to 20,000 L of water to produce with 98% of the water used to produce pasture or feed for the cattle. Worldwide it takes more than 1,000 L of water to produce 1 L of milk. Given it takes 1 L of milk to make 100 g of cheese, the water footprint of cheese is even higher than milk at around 5,000 L of water per kilogram of cheese.

1 kg of chocolate requires around 17,000 L of water – this is due to the water required to make the raw ingredients (sugar, milk and cocoa beans) and the water required to process these raw ingredients into a finished product. Chocolate has, on average, the highest water footprint of any finished food product.


What source of water is most commonly used?

The most common water sources for water intensive crops (and agriculture in general) is rainwater/surface water and groundwater irrigation. Agriculture currently accounts for around 70% of water use worldwide and rice and wheat production currently uses around 45% of available surface water. Surface water sources are attractive to growers as they are close to where the food is produced and usually low in pollutants making them easy to use for growing crops.

However, climate change is causing rainfall patterns to shift leading to a reduced reliability of rainwater harvesting and surface water sources are becoming increasingly polluted. Groundwater sources are not immune to the effects of climate change with groundwater volumes reducing (particularly as extraction rates exceed recharge rates) and groundwater salinity is increasing (either due to a reduction in volume, seawater intrusion or water tables dissolving additional minerals).

What alternatives exist?

One solution is to stop growing water intensive crops. However, while there is still demand in the Western diet for meat and dairy and water intensive crops remain profitable, then these crops will continue to be grown. Additionally, as staple crops like rice and wheat make up the bulk of diets around the world, water use in agriculture is unlikely to significantly decrease in the future.

This leaves two main alternatives: water recycling/water conservation and additional water production.

Water recycling/water conservation
Water conservation efforts on farms such as drip irrigation, mulching and irrigation scheduling can have a big effect on the water footprint of crops. California produces the bulk of the almond supply for the United States of America and around 80% of almonds worldwide. Although almond farming in California uses 10% of the state’s water supply each year, water conservation measures have led to a 30% reduction in the amount of water required to grow almonds when compared with the global average.

Water recycling can have an even greater effect on the overall water footprint when compared with conservation methods as the waste water onsite can be recycled for further use. Meat processing can require large volumes of water to produce finished meat products. A typical abattoir will use 280,000 L of water per day for sterilisation and cooling, however effluent from abattoirs, following primary and secondary treatment, can be used for irrigation or, following additional treatment, higher value uses. The dairy industry was an early adopter of water recycling practices and uses water treatment technologies like membrane filtration to allow for the water used during dairy processing to be reused onsite.

Water production
There is a limit to water efficiency improvements and what end uses recycled water can be put to. Therefore in addition to improving water efficiency and recycling water on both farms and at food processing sites, non-traditional sources of water are increasingly being used to produce water for water intensive crop production. Due to the cost of additional treatment, water production technologies will generally focus on the best available sources of water not currently being used. Technologies are available which can remove sediment, disinfect contaminated sources and remove heavy metals. Due to climate change, aquifers are becoming more saline, and brackish water desalination technologies are being used for crop production or to grow fodder for livestock.

Find out more about Moerk Water’s water treatment solutions, including those that can be used to reduce the water burden on farms, by heading to our Technological Solutions page