At Nazarbayev University's National Laboratory in Astana, researchers have created a seed coating that could transform how farmers in water-stressed regions grow crops. The coating is made not from the petroleum-based polymers that dominate agriculture today, but from starch and carboxymethyl cellulose—natural materials that break down safely in soil and absorb water like a sponge.
The challenge behind this innovation is urgent and familiar to farmers worldwide. As climate change intensifies droughts and soil degrades under pressure, young seedlings face a critical vulnerability: they need consistent moisture during those first crucial weeks of growth. In arid and semi-arid regions, that moisture often simply isn't there. Conventional seed coatings exist, but many rely on synthetic superabsorbent polymers derived from oil, leaving residues that persist in soil long after the plants they protected have matured.
The Nazarbayev team, led by researchers including Raikhan Rakhmetullayeva, took a different approach. They synthesized hydrogels from renewable, biodegradable materials and tested various combinations to see which performed best. The results were striking. The hydrogels could absorb up to 17.5 grams of water per gram of material—a capacity comparable to commercial superabsorbents, but with a crucial difference. Scanning electron microscopy revealed a porous structure perfectly suited to water uptake, and spectroscopic analysis confirmed the formation of a stable crosslinked polymer network. Even more importantly, the materials showed around 67% degradation in soil during the study period, meaning they wouldn't accumulate in farmland.
When the team applied these hydrogels as a seed coating on sugar beet seeds, the difference was dramatic. Coated seeds produced seedlings that reached about 6 centimeters in length, compared with roughly 3 centimeters for uncoated seeds—a doubling of early growth. The improvement came from the hydrogel's ability to absorb water and then release it gradually around the seed as it germinates, providing a steady supply during those vulnerable early days when soil moisture may be sparse.
The researchers also experimented with adding wood ash to the coating composition. This addition proved particularly clever: wood ash contains essential minerals like potassium, calcium, and phosphorus that seedlings need, while the hydrogel layer manages water delivery. The ash–polymer–ash structure emerged as one of the most promising combinations tested, suggesting a way to deliver both moisture and nutrients in a single coating.
The work, published in Scientific Reports in 2025, points toward a future where seed coatings are both functional and environmentally benign. The authors acknowledge that further optimization is needed—particularly around mechanical stability during handling, long-term field performance, and ensuring all crosslinking agents are safe. But the foundation is solid. For regions facing water scarcity or soil degradation, this technology could mean higher germination rates, stronger seedling establishment, and reduced waste of water and nutrients.
In an era when agricultural sustainability is not optional but essential, a coating made from starch and cellulose, rather than oil-derived polymers, may seem like a small change. But for farmers in water-limited landscapes, it could mean the difference between a successful crop and a failed one.