https://www.selleckchem.com/pr....oducts/pclx-001-ddd8
This paper analyzed the compositional and structural changes of humic acid (HA) after combined with phosphate fertilizer (PHA), and investigated its effects on the growth of maize seedlings with four humic acid concentrations. The results showed that the atomic ratios of O/C and (O + N)/N of PHA were significantly lower than those of HA, which indicated that PHA had poor hydrophilicity compared with HA. The spectra of FTIR and NMR results suggested that the relative content of carboxyl group in PHA was higher than that in HA.