Evaluation of phosphorus runoff from sandy soils under conservation tillage with surface broadcasted recovered phosphates

Authors: Sohoulande, Clement; Szogi, Ariel; Stone, Kenneth; Sigua, Gilbert; Martin, Jerry; Shumaker, Paul; BAUER, PHILIP - Retired ARS Employee

Submitted to: Journal of Environmental Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/7/2022
Publication Date: 12/9/2022
Citation: Sohoulande Djebou, D.C., Szogi, A.A., Stone, K.C., Sigua, G.C., Martin, J.H., Shumaker, P.D., Bauer, P.J. 2022. Evaluation of phosphorus runoff from sandy soils under conservation tillage with surface broadcasted recovered phosphates. Journal of Environmental Management. 328:117005. https://doi.org/10.1016/j.jenvman.2022.117005.
DOI: https://doi.org/10.1016/j.jenvman.2022.117005

Interpretive Summary: Potential new sources of phosphorus fertilizers are the recovered P from livestock wastewater through chemical precipitation and the ash from combusting animal manures. Although most of the research on phosphorus fertilizers losses from conservation tillage include commercial fertilizer sources, information on the use of recycled phosphorus fertilizers sources is scarce. The objective of this study was to investigate the phosphorus runoff from sandy soils under conservation tillage, fertilized with phosphates recovered from liquid swine manure and turkey litter ash in comparison with commercial fertilizer triple superphosphate (TSP). Rainfall was simulated on sandy soil plots treated with the three phosphorus fertilizer sources including the recovered phosphorus from liquid swine manure, turkey litter ash, and TSP. The runoff was monitored and sampled every 5 minutes during the test and composite soil samples were collected from the top (0-15 cm) and subsurface (15-30 cm) soil layers in each runoff plot. The experiment included the Noboco and Norfolk soils. Laboratory analyses were conducted to measure both total and soluble phosphorus in runoff samples and the plant available phosphorus in the top and subsurface soil layers following the rainfall simulation on the treated plots. Results show that the quantity of soluble phosphorus runoff from plots treated with the recovered P from swine manure and turkey litter ash represent respectively 1% and 7 to 8% of soluble P runoff from plots treated with TSP. These results support the use of the recovered phosphorus from swine manure and turkey litter ash as crop fertilizer through surface broadcast application.

Technical Abstract: Potential new sources of phosphorus (P) fertilizers are the recovered P from livestock wastewater through chemical precipitation and the ash from combusting animal manures. Although most of the research on P losses from conservation tillage include high-water soluble P commercial fertilizer sources, information on the use of non-conventional, low-water soluble, recycled P sources is scarce. The objective of this study was to investigate the potential P runoff from sandy soils under conservation tillage, fertilized with phosphates recovered from liquid swine manure and turkey litter ash in comparison with commercial P fertilizer triple superphosphate (TSP). Simulated rain corresponding to the annual 30-minute rainfall in the study site (Florence, South Carolina) was applied to plots treated with the three P fertilizer sources and one control. The P fertilizer sources included recovered P from liquid swine manure, turkey litter ash, and TSP. The runoff was monitored and sampled every 5 minutes during the test and composite soil samples were collected from the top (0-15 cm) and subsurface (15-30 cm) soil layers in each runoff plot. The experiment included the Noboco and Norfolk soils. Laboratory analyses were conducted to quantify both total and soluble P wash-off in runoff samples and the plant available P in the top and subsurface soil layers following the rainfall simulation on the treated plots. Results show that the quantity of soluble P runoff from plots treated with the recovered P from swine manure and turkey litter ash represent respectively 1% and 7 to 8% of soluble P runoff from plots treated with TSP. These results sustain the use of the recovered P from swine manure and turkey litter ash as crop P fertilizer through surface broadcast application.