Tomsk Polytechnic University researchers will improve the technology for obtaining mineral fertilizers by modifying the argillaceous glauconite minerals and smectite. The developed smart fertilizers are environmentally friendly, effective when applied to the soil, and have a “targeted” effect. Previously, scientists have demonstrated the possibility of using mineral nanocomposites based on mixtures of traditional nutrients with glauconite and smectite as non-traditional additives. Now they are looking for the best ways to introduce useful components into the crystal structure of minerals to increase the efficiency of smart fertilizers. The study is supported by a grant from the Russian Science Foundation.
The study of glauconite and smectite as useful materials for the agricultural industry has been carried out by specialists from the TPU School of Earth Science and Engineering for eight years. This led to the creation of a new scientific direction in the field of non-traditional types of mineral fertilizers, which is based on an interdisciplinary approach to the use of clay materials in agriculture.
“The study of glauconite and smectite as the basis for composite fertilizers is very promising. Glauconite has a high potassium value. By adding nitrogen and phosphorus to it, minerals can be obtained. These minerals contain the three main nutrients for plant growth and development. An important property of many clay minerals is their good swelling capacity, which can provide a high-quality incapsulation of nutrients into their structure. Due to this, “smart” fertilizers, unlike traditional ones, do not lead to an excess amount of nitrogen compounds that adversely affect the environment. That is, they are more environmentally friendly,”
Maxim Rudmin, associate professor of the TPU Division for Geology, explains.
Smectite and glaucomite are often stored as mining waste. Nanocomposite fertilizers based on them will be inexpensive to manufacture in the future. Also, the development of polytechnics will reduce the amount of mining waste due to their processing.
The activation method was used in various types of mills to obtain "smart" fertilizers. During the study, researchers selected the optimal parameters for the ratio of mineral and nutrient, as well as the time and type of activation, to obtain composites with the required properties.
As part of the project continuation, which is supported by a grant from the Russian Science Foundation, Tomsk Polytechnic University researchers are going to develop ways to improve the efficiency of “smart” fertilizers. This is possible when useful elements are introduced into the crystal structure of minerals. In particular, phosphorus and nitrogen.
“We considered glauconite primarily as a potassium source for plants. The unique granular form of the mineral contributes to the improvement of the soil's physical-mechanical and physicochemical properties. In particular, this allows to avoid an increase in its clay content. Smectite is a moisture-absorbing mineral. Its modification will increase the “absorption” of the nutrient for delivery to plants without deteriorating the soil filtration properties. To do this, you need to work with the morphology of minerals. At the same time, it is important to make sure that when useful elements are introduced into the crystal structure of the mineral, it does not collapse,”
says Maxim Rudmin.
It is assumed that modified “smart” fertilizers will have a controlled rate of nitrogen release.
As part of the study, it is also planned to identify and test multi-level principles for the creation of multifunctional fertilizers from glauconite and smectite. Achieving these results will rely on an understanding of mineralogical features and structural transformations at various stages of a potential production cycle.