Аннотация:Biodegradation is one of the main factors limiting the efficiency and life time of gel-forming soil conditioners. The study quantifies this process using a laboratory analysis of biological oxygen demand (BOD) in innovative composite superabsorbents with an acrylic polymer matrix, amphiphilic agents (humates, peat), and silver ions as an inhibitor of biological activity. A simple kinetic model of BOD was proposed to standardize the analysis and calculate the half-life of polymers after their incubation in VELP precisionrespirometers (Italy). A half-life of hydrogels swollen in a distilled water (1 : 100) at a temperature of 30оC varied in the range from 0.8 ± 0.2 to 2.4 ± 1.6 years. The addition of water extract from the compost sharply enhances biodegradation and decreases the half-life of hydrogels to 40–60 days. Doses of 0.1–1% silver in a polymer matrix or 10–100 ppm in swollen hydrogels increase their half-life by 5–20 times. A new methodological approach allows to estimate completely automatically the biodegradation of gel-formingpolymers under laboratory conditions; however, for stable materials with a half-life more than 2.5–3 years, an accuracy of BOD manometric analyzers is insufficient for a statistically significant estimation of the biodegradation kinetics even in long-term (120 days) incubation experiments.