INFLUENCE OF SODIUM HUMATE CONCENTRATIONS ON THE COMPOSITION AND PROPERTIES OF LIQUID ORGANOMINERAL FERTILIZERS

Abstract

Introduction. The use of liquid organomineral fertilizers (LOMF) based on chelates of
microelements and humates leads not only to an increase in yield and product quality, but also to a
decrease in economic costs. LOMF s have a complex effect on plants, activate various physiological
processes, increase the plant defense mechanism to various stresses and phytopathogens, improve the
structure and properties of the soil. The aim of the work is to study the patterns of the influence of sodium
humate concentrations on the process of obtaining humate-, nitrogen- and molybdenum-containing
LOMFs. Methods. The methods of chemical analysis, an atomic emission spectrometer with inductively
coupled plasma, infrared spectroscopy and thermogravimetric analysis were used. Results and discussion.
Based on chemical and physicochemical analyses, the effect of sodium humate concentrations on the
composition and properties of the synthesized products was determined. The results demonstrated that
increasing sodium humate concentrations from 0.1% to 1.0% led to a rise in the yield of humic acids
(HAdaf) from 33.73% to 38.60%, nitrogen content from 4.21% to 5.27%, and molybdenum content from
0.22% to 0.30%, the amount of COOH - from 1.28 to 1.80 mg-eq/g and OHphen.groups –from 0.34 to 0.70
mg-eq/g. IR spectral analysis revealed that the interaction of sodium humate with ammonium
heptamolybdate results in the formation of a complex compounds. The IR spectra of the LOMF samples
exhibited distinct and well-defined absorption peaks at specific wavelengths, indicating an enrichment
with carboxyl, phenolic, and carbonyl functional groups. Conclusion. Physicochemical investigations of
the synthesized LOMFs confirmed that the interaction of sodium humate with ammonium heptamolybdate
leads to the formation of organomineral chelate complexes incorporating molybdenum ions. The
formation of these complex compounds, alongside increased concentrations of HAdaf, nitrogen,
molybdenum, COOH, and OHphen groups, enhances the biological activity and agrochemical efficacy of
the fertilizers.