Assessing the Effects of Soil Humic and Fulvic Acids on Germination and Early Growth of Native and Introduced Grass Varieties

摘要

A total of n. 28 humic acids (HAs) were extracted by the USDA-St. Paul group using a 0.5 M NaOH solution from duplicate (A, B) or triplicate (A, B, C) samples of the two Wyoming soils, Guernsey North (GN) and Guernsey South (GS), and the one Utah soil, Dugway (D), object of this research, which were collected from greenhouse pots where the four wheatgrass varieties of interest, the cv. Pryor of the native species Slender (3) and its germplasm line SERDP- select (4) and the cv. Vavilov of the introduced species Siberian (2) and its germplasm line SERDP-select (5), were separately grown. All HA samples were characterized by the Bari (this) group for moisture and ash contents, elemental (C, H, N, S, O) and acidic functional group (total acidity, COOH, phenolic OH) composition, and by Fourier transform infrared (FT IR) spectroscopy and fluorescence spectroscopy in the emission, excitation and synchronous scan modes. For the remainder of the contract period (8 months) research plans are the following: (a) Germination and early growth experiments of the three remaining combinations by two of the grass varieties in the presence of the three soil HAs at two concentrations. (b) Comparison of the germination and seedling growth data with the chemical and spectroscopic parameters of the HAs examined, in order to possibly find out which HA parameters may influence germination and growth of the four grass varieties examined, either singularly or in combination by two. (c) Possible follow-up experiments with HA concentrations optimal to promote the growth of the grass varieties of interest.