Glass Beads Retain Nutrients and Prevent Water Pollution

Tiny glass fertilizer beads could keep nutrients in the soil and out of the water

Agricultural fertilizers are a major source of pollution, as chemicals leach out of the soil and contaminate the environment. Scientists are now working on a possible solution to this problem by developing a sustained-release fertilizer made of tiny glass beads.

Challenges of Conventional Fertilizers

Farmers usually apply conventional fertilizers to the soil in liquid, powder, or granular form.

Whichever the case, the substance often doesn’t have enough time to release all of its nutrients before it either leaches into the groundwater or evaporates into the atmosphere. The former leads to water pollution and toxic events like algae blooms, while the latter results in greenhouse gases such as nitrous oxide.

Furthermore, because much of the fertilizer’s nutrients don’t reach plant roots in a single application, farmers must apply the fertilizer multiple times to achieve full effectiveness. Not only does this task release even more pollutants into the environment, but it also adds extra work and costs for the farmers themselves.

This is where the tiny glass beads come in.

The Glass Beads Solution

Developed by a team of Brazilian scientists, the beads start with a solid, water-soluble glass containing common fertilizer nutrients such as phosphorus, calcium, and potassium. The team then grinds this glass into particles ranging from 0.85 to 2 millimeters in size (for reference, sand grains range from about 0.1 to 2 mm). The idea is that as these particles dissolve in moist soil, they gradually release the nutrients.

In greenhouse tests, the researchers fertilized plots of Palisade grass just once with either the glass beads or a liquid fertilizer containing the same nutrients in the same amounts. They then cut and harvested all of these plots 45 days later, followed by four additional harvests every 30 days, allowing the grass to grow back between each harvest.

Although both fertilizer types resulted in an initial growth boost right after application, the bead-fertilized plots ultimately produced about 70% more biomass over the five harvests.

Safety and Effectiveness of Glass Beads

Importantly, the beads were harmlessly absorbed by the soil as they dissolved. In ecotoxicity tests on lettuce and onion seeds, the glass particles did not affect germination rates or cell health compared to traditional fertilizers.

Finally, as an added bonus, the beads may also help plants grow by aerating their roots. The scientists were inspired by a previous study in which recycled bottle glass particles helped oxygenate plant roots while maintaining optimal moisture levels.

Read the original article on: New Atlas

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