EVALUATION OF THE EFFECTIVENESS OF NEMA2 PRODUCT ON SOIL QUALITY

This report presents the results of a soil incubation study conducted to evaluate the effects of the NEMA2 product, a highly active form of organic carbon, on soil properties. The experiment was carried out by Can Tho University in collaboration with Japan Vietnam Smart Future Joint Stock Company (JVSF). Methods: The study used non-acid sulfate surface soil (0-15 cm) from a rice field in Can Tho, Vietnam. A completely randomized design was employed with five treatments and four replications over a 30-day incubation period. The treatments included a control (T1), two rates of NEMA2 application (T2: 200 g/1000 m²; T3: 1000 g/1000 m²), NPK fertilizer alone (T4), and a combination of NPK and NEMA2 (T5). Soil chemical properties (pH, organic matter, NH₄⁺-N, NO₃⁻-N, available P, exchangeable K, Ca, Mg, active Fe) and biological properties (bacterial density) were analyzed using standard methods (TCVN and international protocols). Results: The application of NEMA2 demonstrated several significant effects. The primary mechanism identified was its role as a biological catalyst, providing an easily accessible carbon energy source that significantly increased soil bacterial density. This microbial stimulation accelerated the nitrogen cycle, nearly tripling the concentration of ammonium (NH₄⁺-N) and more than doubling the total available mineral nitrogen (NH₄⁺-N + NO₃⁻-N) compared to the control. NEMA2 also exhibited a strong ion adsorption capacity, temporarily reducing the concentration of available P and K in the soil solution, which is interpreted as a nutrient retention mechanism that prevents leaching and creates a slow-release effect. When combined with NPK fertilizer (T5), NEMA2 showed a synergistic effect, resulting in the highest levels of available nitrogen and bacterial density. The product had minimal short-term effects on soil pH, exchangeable Ca, Mg, and active Fe. Conclusion: The findings indicate that NEMA2 acts as an effective soil amendment by stimulating microbial activity, enhancing nutrient cycling (especially nitrogen), and improving nutrient retention. Its synergistic effect with conventional fertilizers suggests its potential to improve fertilizer use efficiency in agricultural systems.