TY - JOUR
T1 - Phosphorus stocks and pools in eroding streambank soils
AU - Zhou, Shengnan
AU - Margenot, Andrew J.
N1 - This research was supported by the Illinois Nutrient Research and Education Council (NREC) 2021-4-360731-469 and 2023-4-360731-642. We thank Jeff Boeckler (Northwater Consulting), Jennifer Jones (Illinois Soybean Association), and Lauren Spaniol (Coles County Soil & Water Conservation District) for assisting with the streambank survey. We thank Dr. Jasdeep Singh for his advice on the PCA.
This research was supported by the Illinois Nutrient Research and Education Council (NREC) 2021-4-360731-469 and 2023-4-360731-642. We thank Jeff Boeckler (Northwater Consulting), Jennifer Jones (Illinois Soybean Association), and Lauren Spaniol (Coles County Soil & Water Conservation District) for assisting with the streambank survey. We thank Dr. Jasdeep Singh for his advice on the PCA.
PY - 2023/10
Y1 - 2023/10
N2 - Phosphorus (P) in streambank soils can directly enter waterbodies via streambank erosion. How much and what form of P is entailed by this terrestrial-aquatic transfer has implications for the degree and timespans of downstream water quality impacts. Quantifying the bioavailability and spatial distribution of soil P species in streambanks is needed to comprehensively assess the fate of P eroded into streams and their potential risk to downstream water quality. This study quantitatively evaluated the abundance and speciation of P in streambank profiles of Polecat Creek, IL, USA using sequential (Hedley) P fractionation. The HCl extractable fraction, interpreted as Ca-P and insoluble in water, was the dominant form of P accounting for 12–73% of total P (14–344 g m−2) with higher stocks in C horizons (131 ± 26 g m−2) than the overlying B (36 ± 7.6 g m−2) and A (41 ± 12 g m−2) horizons. Ca-P was strongly positively correlated with soil pH and inorganic carbon (IC) content, demonstrating the influence of apatite-rich loess parent material of this region in driving P speciation. Organic P (Org-P) accounted for 1–33% of total P (0.1–104 g m−2) with significantly higher stocks in A horizon (39 ± 5 g m−2) than B (11 ± 7 g m−2) and C (22 ± 7 g m−2) horizons, concomitant with the pattern of organic carbon (OC) and reflective of strong biological (riparian vegetation) controls on this pool of potentially mineralizable P. Subsurface increases in Org-P occurred for buried A horizons in banks created by alluvial depositions indicated the strong influence of fluvial processes on streambank P distribution and speciation. Fe/Al-P accounted for 1–21% of total P stocks and was generally enriched in the surface A (50 ± 30 mg kg−1) and B (35 ± 39 mg kg−1) horizons. The most immediately bioavailable pool, exchangeable P (Exc-P), was the smallest across streambanks, constituting < 10% of total P and largely relegated to A horizon (1.2–20.4 g m−2). This proof of concept offers valuable information about the variation of P stocks and speciation by genetic horizons in streambanks.
AB - Phosphorus (P) in streambank soils can directly enter waterbodies via streambank erosion. How much and what form of P is entailed by this terrestrial-aquatic transfer has implications for the degree and timespans of downstream water quality impacts. Quantifying the bioavailability and spatial distribution of soil P species in streambanks is needed to comprehensively assess the fate of P eroded into streams and their potential risk to downstream water quality. This study quantitatively evaluated the abundance and speciation of P in streambank profiles of Polecat Creek, IL, USA using sequential (Hedley) P fractionation. The HCl extractable fraction, interpreted as Ca-P and insoluble in water, was the dominant form of P accounting for 12–73% of total P (14–344 g m−2) with higher stocks in C horizons (131 ± 26 g m−2) than the overlying B (36 ± 7.6 g m−2) and A (41 ± 12 g m−2) horizons. Ca-P was strongly positively correlated with soil pH and inorganic carbon (IC) content, demonstrating the influence of apatite-rich loess parent material of this region in driving P speciation. Organic P (Org-P) accounted for 1–33% of total P (0.1–104 g m−2) with significantly higher stocks in A horizon (39 ± 5 g m−2) than B (11 ± 7 g m−2) and C (22 ± 7 g m−2) horizons, concomitant with the pattern of organic carbon (OC) and reflective of strong biological (riparian vegetation) controls on this pool of potentially mineralizable P. Subsurface increases in Org-P occurred for buried A horizons in banks created by alluvial depositions indicated the strong influence of fluvial processes on streambank P distribution and speciation. Fe/Al-P accounted for 1–21% of total P stocks and was generally enriched in the surface A (50 ± 30 mg kg−1) and B (35 ± 39 mg kg−1) horizons. The most immediately bioavailable pool, exchangeable P (Exc-P), was the smallest across streambanks, constituting < 10% of total P and largely relegated to A horizon (1.2–20.4 g m−2). This proof of concept offers valuable information about the variation of P stocks and speciation by genetic horizons in streambanks.
KW - Genetic horizon sampling
KW - Phosphorus speciation and stocks
KW - Streambanks
KW - Water quality
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U2 - 10.1016/j.catena.2023.107305
DO - 10.1016/j.catena.2023.107305
M3 - Article
AN - SCOPUS:85163179219
SN - 0341-8162
VL - 231
JO - Catena
JF - Catena
M1 - 107305
ER -