Scientists from Tomsk Polytechnic University together with their colleagues from the Czech Republic have developed a new hydrogel for agriculture. Its task is to retain moisture and fertilizers in the soil. The difference of the new hydrogel from other products is that it is made entirely of natural components and decomposes in the soil into non-toxic components for humans, animals and plants. The study was published in the Journal of Cleaner Production (IF: 7,246; Q1), reports World of NAN, citing the news service of Tomsk Polytechnic University.
Hydrogels are used in agriculture and forestry to retain moisture in the soil, as its content directly affects the germination of seeds. They also contain fertilizers. Due to the fact that the gel does not allow fertilizers to evaporate quickly, they can be applied in smaller amounts.
"With hydrogels, plants can be watered less often and less fertilizer can be used. This is important for rational use of fresh water. It also reduces the harmful effects of fertilizers on the soil. Most of the hydrogels available on the market are made from polyacrylamide and polyacrylonitrile. They are not fully biodegradable, so they are themselves considered potential soil contaminants. The components themselves are non-toxic, but commercial developments contain acrylamide residues, and this is a neurotoxic and carcinogenic substance.
We used whey protein and alginic acid as starting ingredients. These are available and natural components, and they are absolutely non-toxic. This is the main advantage of our hydrogel," says one of the authors of the article, associate professor at TPU Research School of Chemical and Biomedical Technologies Antonio Di Martino.
The process of obtaining the hydrogel proposed by the authors of the study is simple: the initial components must be mixed, dried and pressed into the form of a tablet. On contact with a liquid, the substance becomes gel-like and increases in volume.
"In obtaining the mixture, we also added urea, which is a well-known fertilizer. Over time, the hydrogel decomposes in the soil, whereby it gradually and evenly releases the fertilizer. In addition, the hydrogel itself decomposes into carbon and nitrogen over time, and nitrogen is a macronutrient widely used in agriculture, the most important building material for plants. At the same time, experiments in the laboratory showed that hydrogel can be used a few more times after the full return of moisture, "- said Antonio Di Martino.
In the future the scientists will continue to experiment and look for new materials for controlled fertilization of the soil.
Scientists from Tomáš Baťa University in Zlín (Czech Republic), the Dairy Industry Research Institute (Czech Republic) and the Soil and Water Conservation Research Institute (Czech Republic) took part in the study.