Effect of mineral fertilizer encapsulated with zeolite and polyethylene terephthalate on the soil microbiota, pH and plant germination

Environmental risks caused by the use of traditional mineral fertilizers require new agro-technical solutions, which are encapsulated long-acting fertilizers. The use of the capsule allows to reduce the concentration of mineral compounds in the fertilizer and to minimize the adverse effects of the chemical compounds contained in it on the environment. Encapsulated fertilizers provide more efficient absorption of mineral nutrition by plants, allowing to synchronize the release of elements in accordance with the needs of the plant. The use of natural materials as fertilizer shells is faced with the problem of their low solubility and cost, and the use of synthetic coatings with the problems of their biodegradation in the environment. The development of new environmentally friendly materials for long-acting fertilizer capsules is a challenge for modern society. In this context, a universal mineral fertilizer coated with a coating of natural zeolite sorbent and diethylene glycol (DEG) modified polyethyl terephthalate (PET) is promising. We analyzed the influence of fertilizer on the kinetics of soil pH change, the dynamics of the total microbial count and the increase in the number of microorganisms and the germination of Hordeum sativum and Lolium perenne. The application of fertilizer for 28 days of the experiment led to decrease in soil pH by 0.3. In the presence of encapsulated fertilizer the germination of ryegrass seeds was 3.51 times higher, and ones of barley 4.14 times higher than without fertilizer. The fertilizer provided a prolonged release of minerals, which had a positive effect on the germination of barley and ryegrass plants, stimulated plant growth and increased the total number of microorganisms in the soil as an important indicator of the efficiency of agricultural technology

Bioelectricity production in an indoor plant-microbial biotechnological system with Alisma plantago-aquatica

The paper descibes the development of a biotechnological system for generating bioelectricity on closed balconies of buildings from living plants Alisma plantago-aquatica and soil microorganisms grown in containers with natural wetland substrate, provided with a graphite and Zn-galvanized steel electrode system. This biotechnology worked efficiently from the first days after installation and was practically at full capacity 2 weeks later. Electric power output was highest in the spring-summer and the early autumn period (at the time of the highest photosynthetic activity of plants). The highest current output was 58.6 mA at 10 Ω load. Bioelectricity generation by the biosystem was stable with slight fluctuations throughout the year in well-lighted and heated premises at a temperature of 21-26 °C, and the seasonal reduction of the bioelectricity level was 8.71%. On not-heated closed terraces and glazed balconies, with temperature fluctuations from 5 to 26 °C, the electricity production decreased in the winter period by 19.98% and 39.91% with and without adding of sulfate-reducing bacteria, respectively. The proposed system of electrodes for collection of bioelectric power is new, easy to manufacture and economical. It is resistant to waterlogged environment, and has good prospects for further improvements for more effective collection of plant-microbial bioelectricity. Maintainance of the biosystem is simple and accessible to everyone without special skills