Thirsty crops cause water shortages and pollution

Lack of sustainable agriculture: Biggest threat to the environment

Agriculture, the largest industry in the world, is also the biggest threat to the environment. Inefficient food production and harmful agriculture subsidies are causing deforestation, water shortages and pollution.

Agriculture wastes 60% or 1,500 trillion litres, of the 2,500 trillion litres of water it uses each year - this is 70% of the world’s accessible water ¹.

Many big food producing countries like the US, China, India, Pakistan, Australia and Spain have reached, or are close to reaching, their renewable water resource limits.

The lack of sustainable agriculture harms the environment by sucking rivers, lakes and underground water sources dry, increasing soil salinity and thereby destroying its quality, and by washing pollutants and pesticides into rivers that in turn destroy downstream ecosystems such as corals and breeding grounds for fish in coastal areas.

The main causes are:

• leaky irrigation systems;
• wasteful field application methods;
• pollution by agri-chemicals; and
• cultivation of thirsty crops not suited to the environment.

The waste and pollution of water is made worse by misdirected subsidies, low public and political awareness of the crisis, and weak environmental legislation.

A WWF report, Thirsty Crops: Agricultural Water Use and River Basin Conservation, identifies cotton, rice, sugar cane and wheat as the 'thirstiest' crops in 9 large river basins rich in biodiversity. Together, these 4 crops account for 58% of the world's irrigated farmland.

Cotton farming

Cotton represents nearly half the fibre used to make clothes and other textiles worldwide.

In Latin America, Africa and Asia, cotton is one of the most important cash crops for small farmers.

Although only 2.4% of the world's cropland is planted with cotton, it accounts for 24% of the world’s insecticide market and 11% of sale of global pesticides. 73% of global cotton harvest comes from areas under irrigation.

Diversion of water and its pollution by cotton growing has had severe impacts on major ecosystems such as the Aral Sea in Central Asia, the Indus Delta in Pakistan and the Murray Darling River in Australia.

More on the impact of cotton on freshwater >>

Sugar production

Sugarcane plantations in many tropical and sub-tropical countries have led to perhaps the largest losses of biodiversity caused by any single agricultural product.

Although much of this habitat and species loss is historic, sugar production today - whether from cane or beet - has a wide range of negative impacts on soil, water and air. The Great Barrier Reef off Australia's coast, which suffers from effluents and sediment from sugar farms, is one of the best known examples.

Perverse subsidies and market barriers enable EU and US farmers to grow sugar cheaply and to dump it on the world market, with consequent economic, social and environmental impacts in developing countries (as highlighted again in a recent WTO ruling).

More on the impact of sugar cane plantations on freshwater >>

Rice cultivation

Half the world depends on rice – as a food staple, source of income, or both.

More than 90% of the rice that reaches our tables is grown in Asia. Traditional farming needs 3,000 to 5,000 litres of water to produce a kilo of rice. By using the 'system of rice intensification' (SRI), more rice can be grown per litre. Results from SRI pilot projects in India, supported by WWF, have shown substantial increases in crop yields – and farmer incomes – while using about 30% less water.



-------------

¹ Clay, J. 2004. WORLD AGRICULTURE AND THE ENVIRONMENT A Commodity-by-Commodity Guide to Impacts and Practices, Island Press