Hydrogel is a synthetic polyacrylamide that has a great ability to retain and store water. It is known as a substance which, when added to soil, improves the physiological and morphological properties of plants, increases their viability, water efficiency and dry matter production. With its properties, it helps the plant to keep soil microorganisms in the rhizosphere (i.e. the area of ??the soil around the roots and in their immediate vicinity) and thus increases the availability of nutrients. Hydrogel application to the soil also significantly reduces the plant's demands on the amount of fertilizer, even by up to 20%. It is therefore not surprising that many studies look into the positive effect of the hydrogel on forest trees in areas with low rainfall or in soils with insufficient retention capacity.
The question arises as to whether the hydrogel could have a wider use in semiarid and arid areas, where the natural lack of precipitation is exacerbated by the effects of climate change. One such area is Iran, which is currently experiencing major environmental changes due to climate change. Over the past few decades, a significant year-on-year decrease in precipitation has been observed in the territory of Iran. The next decade is expected to increase temperatures by up to 2 °C and this warming could cause, among other things, a further reduction in precipitation of up to 35%. Although Iran is a country with a predominantly arid or semiarid climate, even temperate areas around the Caspian Sea are already at risk. The combination of human activity and climate change has caused a 43% loss of forest area over the last forty years. Could a "hydrogel injection" be a lifeline for the local forests? A team of researchers from the Faculty of Forestry and Wood Sciences also asked this question.
The experiment was performed on twenty species of woody plants commonly growing in the regions of West Asia, and both drought-resistant and drought-sensitive species were selected. A total of 7 groups were created, each containing all 20 species. One group of individuals was left as a control, i.e. without the addition of hydrogel and fertilizer, to the remaining six hydrogel in combination with different fertilizing substrates was added. After six months of growth in the given substrate, the height of the individuals and their health condition were evaluated. The survival rate of all tested species, their growth in height and health status increased significantly in the groups treated with hydrogel in comparison with the control group. The average survival of the hydrogel-treated groups was 81%, while the control group was just 37%. Without the addition of hydrogel, even species that are generally considered to be drought resistant were in poor health.
The conclusions of the study thus confirmed that the application of the hydrogel has a positive effect on the growth of woody plants, especially those that are sensitive to drought. The positive news is especially that the application of hydrogel during planting is a simple and cheap method. In agriculture, the hydrogel has been a well-known helper for almost 30 years. Now it represents a promising way to save forests from the effects of climate change and ensure not only their ecological stability, but also the production of timber for countries affected by climate change.
doc. Ing. Ivana Tomášková, Ph.D.
Ivana Tomášková has been working at the Faculty of Forestry and Wood Sciences for nine years. She acted as a member of the Academic Council and also as a member of the Academic Senate of the faculty. She teaches several subjects, such as Plant Anatomy and Physiology. At the Department of Genetics and Physiology of Forest Trees, her research is focused mainly on plant physiology, but her outputs often combine aspects of other areas of research such as genetics, breeding and forest protection.
Author: Dagmar Zádrapová