Agriculture and Environment: Rice

Environmental Impacts of Production: Water Use

Irrigated rice requires about 1,200 millimetres of water per crop.

This amounts to some 5,000 litres per kilogram of rice produced. In some areas water use for rice cultivation causes salinization of soils, making the land less fertile. Rice is a large and inefficient consumer of water, even by today's agricultural standards.

The impacts of the total water withdrawals on biodiversity and ecosystem functions are not well studied. For example, it is not known whether taking water for rice cultivation and reducing flooding during rainy season is better or worse for biodiversity than taking water from river systems during the dry season.

The provision of water for rice production causes collateral damage as well. Many dams have been constructed to provide water for the irrigation of rice. These dams prevent migration within freshwater ecosystems and as a result reduce biodiversity.

Dams and irrigation systems also increase disease vectors by providing breeding grounds for mosquitoes and other hosts who transmit the diseases where they did not exist before. These can include organisms causing bilharzia (schistosomiasis), malaria, and even diarrhoea.