Modified Humic Substances as Soil Conditioners: Laboratory and Field Trials

The paper is devoted to the development and performance testing of a soil conditioner based on leonardite humic substances (LHS) modified with 3-aminopropyltriethoxysilane (APTES). HS were obtained by adding APTES LHS solution at different mass ratios APTES, followed investigation siloxane structures using 31Si NMR spectroscopy. Urbic Technosol was used as model soil. size amount water-stable aggregates estimated wet sieving laser diffraction, respectively. Toxicity evaluated monitoring microbial substrate-induced respiration (SIR) seedling bioassay. Laboratory column experiments demonstrated an increase in water-stability 3–5 mm after LHS-APTES application. Field tests showed average weighted diameter micro (from 59 73 ?m) macroaggregates 1.6 2.9 mm) due amendment. A substantial SIR from 5 9 mg CO2 (kg h)?1 detected. Better survival seedlings observed. beneficial results indicate that APTES-modified can be successfully conditioner. formation extended networks suggested main mechanism observed improvement structure amended soils.