Never Again Droughts: Solid Rain, a Mexican Innovation
Comment of the Day

July 22 2013

Commentary by David Fuller

Never Again Droughts: Solid Rain, a Mexican Innovation

Here is an interesting, short article from the World Farmers' Organisation
As an alternative to the problem of drought suffered by some northern states in Mexico and in order to improve the efficiency of agricultural irrigation systems, a Mexican engineer, Sergio Jesus Rico Velasco, has developed a system for planting solidified water in crop fields.

The technology developed by Rico Velasco consists in the activation series of components - and namely Water silos (which are potassium polyacrylate powder particles) - whose molecular structure allows them to absorb and retain up to 500 times their liquid weight and form small potential water reservoirs, becoming Solid Rain when they are hydrated and grow thanks to the water's effect.

Solid Rain is the result of Water Silos bonding together with previously captured rainwater - which is usually collected from roofs, in the necessary quantities (i.e. 10 grams per liter of water) - and is stored in a location which is not exposed to the sun, with a view to subsequently being used even one year after being collected in plantations and crops.

The Water Silos particles - which can be removed and then be re-hydrated at every crop cycle - have a life span of up to 10 years, during which time they will provide plants with a regular supply of water by allowing the plant to be ventilated and preventing evaporation.

Water silos' effectiveness has been fully proven. Mr. Rico Velasco conducted, in fact, in 2005 a comparative study of the corn fields located outside the village of Aguahedionda in the Jalisco region, during which he applied the two irrigation systems, and namely a traditional, rain-fed liquid irrigation system, which harvested 600 kilograms per hectare, and a Solid Rain irrigation system, with which he collected 10 tons of grain per hectare.

This technology has also been successfully used in India in the cultivation of papaya, mango, peanut, cotton, wheat and coconut palms, as well as in Colombia in rose and carnation greenhouses. Researchers recorded 75% savings in irrigation costs, as well as a 100% increase in foliage and flowers and a 300% in root development.

The ongoing process of desertification, climate change and uncertainty about rain seasons make this project of vital importance since it offers the possibility of storing rainwater in bags and in solid form, allowing it to be transported to places which can reached with great difficulty.

The aforementioned technology has, moreover, not been patented and, as such, is in the public domain, with the result that it can be used for the benefit of all mankind.

Mr. Rico Velasco's solid water irrigation system has led to the latter being nominated for the Global Water Award 2012, which is awarded each year by Stockholm International Water Institute (SIWI) located in Stockholm, Sweden.

David Fuller's view This seems too good to be true, but hopefully is not. I do not know anything about absorbent polymers but we need to know if there are any downsides to potassium polyacrylate? For instance, is it absorbed by food crops, and if so, what would be the effect on humans and animals? The articles say it remains effective in soils for 10 years, but what happens to this absorbant thereafter? Does it biodegrade or does it become a sludge which is potentially harmful and needs to be removed?

Meanwhile, Solid Rain's creator, although not the original inventor, Sergio Jésus Rico Velasco, a Mexican chemical engineer, cites another benefit in this article from Modern Farmer:

Lorenzo also touts a side benefit of Solid Rain: it prevents nutrients in the soil from washing away. Frank Torres, a former green bean farmer in the Mexican state of Sinaloa, used Solid Rain even though drought wasn't a big issue in his area. Still, he said yields increased by about 50 percent. "Nitrogen wasn't washing away every time we watered the plants," Torres said. "All the nutrients were absorbed into the roots."

There are 40 interesting comments following this article from Modern Farmer, including responses from, which at least partially address my questions above and a number of others which are extremely important.

If there are no unwelcome side effects from potassium polyacrylate, and that is a big IF, Solid Rain should have the potential to reduce considerably the problem of drought in agricultural regions. That would increase agricultural supplies, which in turn, could reduce malnutrition in poorer countries. In other words, Solid Rain could be another global 'game changer'.

Lastly, here is a 2.5 minute video on Solid Rain from Scientific American.

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