When rice is washed, the wash water becomes whitish due to the starchy powder in the skin of unwashed rice. I've often heard or read, usually in water-saving, money-saving, or gardening tips, that the water used to wash rice is beneficial for plants as it fertilizes the soil. There are also various anecdotes on the internet suggesting the use of rice water to water plants:
- The Concrete Canopy: Rice-water
- Can Rice Water Replace fertilizer in plant growth?
- Green Culture: rice water as fertilizer
- Is Rice Water Good for Plants?
Surprisingly though, given how often I've heard this claim, I hadn't been able to find much serious researches regarding this topic.
Are there any truth to this claim? Does watering plants with rice water produces better plants than watering plants with plain tap water? How does it compare with regular, commercially produced fertilizers?