Reliability is one of the main characteristics of ecosystem, its ability to effectively maintain its structure and perform functions without fail when environmental conditions change due to natural or anthropogenic negative impacts. It is shown that in the assessment of ecosystems, the leading role belongs to environmental monitoring to determine the condition of ecosystem components and identify the possibility of ensuring reliability. Methodical approaches to environmental monitoring have been developed. Mechanisms of ensuring and principles of reliability assessment of different types of ecosystems are considered. The main attention is paid to the recovery, reservation and conditioning of ecosystems under the influence of negative factors. To quantify the ability of ecosystems to recover, it is proposed to use appropriate criteria, which are determined by certain calculation formulas. With insufficient reliability of ecosystem elements due to the actions of negative factors, its reliability is ensured by reservation at the expense of additional means and capabilities. In the case of agroecosystems, which are artificially created biotic groups of organisms that are supported by humans, it is an integrated approach using the theory of ecosystem reliability that expands the range of means to study their effective functioning. It is noted that the increase in the reliability of the agroecosystem is provided by the use of its reliable elements, as well as special systems for ensuring recovery and reservation. It is emphasized that the application of reliability theory in the study of agroecosystems contributes to the management of their functional efficiency for obtaining environmentally safe products

The multicomponent nature of agroecosystem pollution complicates the effectiveness of the ecotoxicological control. The danger of the combined pesticide and cadmium soil load was investigated in the laboratory conditions using agricultural plants (test crops). The aim of the study was an integral assessment of the complex impact of pesticide and cadmium soil contamination on wheat Triticum aestivum L. by biotesting. The widely used pesticides in agriculture were tested: systemic fungicides Azimut (a.i.: tebuconazole, 125 g/dm³ + triadimefon, 100 g/dm³), Azimut Classic (a.i.: tebuconazole, 250 g/dm³) and soil-acting herbicide Extrabit (a.i.: S-metolachlor, 960 g/dm³). The levels of Cadmium accumulation by plants (by inductively coupled plasma atomic emission spectroscopy) and pesticide active ingredients (by high-performance liquid chromatography with a mass detector) were determined. It was found that a exceeding the rate of pesticide application leads to their accumulation by plants. At combined soil load with Cadmium (3-fold maximum allowable concentration, MAC) and the associated pesticide, an increase in the accumulation of active ingredients by plants is observed (tebuconazole by 1.85 and 1.47 times for Azimut and Azimut Classic, respectively, and S-metolachlor by 1.47 times for Extrabit) compared to a single pesticide. In addition, phytotoxicity of pesticides was noted in the conditions of the experiment. Thus, for the fungicide Azimut and the herbicide Extrabit, a decrease in the initial growth rate of plants (length of roots and seedlings) by more than 40 % was found, which indicates a level of phytotoxicity above average. It was concluded that new pesticide formulations (including soil-acting pesticides) should be tested for toxicity in relation to higher plants. This is important for development of countermeasures to reduce pesticide accumulation in agricultural plants, especially in conditions of soil contamination with heavy metals. Key words: biotesting, combined action, pesticides, cadmium, phytotoxicity, Triticum aestivum L.

When improving agricultural technologies, considerable attention should be paid to the use of organic fertilizers, which involves the use of humic and fulvic acids. This will reduce the use of mineral fertilizers and increase the yield of agricultural products, as well as grow environmentally friendly products. Justification of the use of organic fertilizers to stimulate plant growth requires a preliminary study of their action under laboratory conditions. The article analyzes the wide application of biotesting procedures based on the reactions of living organisms, using plant test-objects. The availability of a wide range of plants allows their use for testing various factors, including the analysis of the stimulating effect of substances on higher plants. The purpose of the study was to study the effect of the organic fertilizer «Grееnat» on the initial growth processes of higher plants in the laboratory by biotesting. The methodology of the study was to apply the biotesting method using higher plants widely used in agriculture, namely barley (Hordeum vulgare L.), soybeans (Glycine max L.), wheat (Triticum aestivum L.), maize (Zea mays L.), cucumber (Cucumis sativus L.), tomato (Solanum lycopersicum L.). Іt is established that the declared organic fertilizer «Greenat» contains: humic acids (67,68 g/dm3), fulvic acids (24,37 g/dm3) and organic substances (53,39%). The stimulating effect of the studied fertilizer on the initial processes of growth and formation of the root system of representatives of the group of cereals – barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) was revealed. Stimulating effect of organic fertilizer is also established for the initial growth processes of soybeans by estimating the length of shoots (increase by 38%) and for the initial growth processes of corn by estimating root length (increase by 22%). Root length of cucumber and tomato increased by 23 and 21% respectively, indicating the stimulating effect of the organic fertilizer «Greenаt» in the treatment of seeds of vegetable crops. The results of the research indicate the effectiveness of using the organic fertilizer «Grееnat» at the stage of seed treatment to stimulate the energy of germination and development of the root system of plants.