Location: Soil Dynamics Research
Title: Understanding the environmental impacts of phosphorus in acidic soils receiving repeated poultry litter applicationsAuthor
CHAKRABORTY, DEBOLINA - Auburn University | |
PRASAD, RISHI - Auburn University | |
BHATTA, ANJAN - Auburn University | |
Torbert, Henry - Allen |
Submitted to: Science of the Total Environment
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/28/2021 Publication Date: 3/8/2021 Publication URL: https://handle.nal.usda.gov/10113/7306735 Citation: Chakraborty, D., Prasad, R., Bhatta, A., Torbert Iii, H.A. 2021. Understanding the environmental impacts of phosphorus in acidic soils receiving repeated poultry litter applications. Science of the Total Environment. 779(2021):146267. https://doi.org/10.1016/j.scitotenv.2021.146267. DOI: https://doi.org/10.1016/j.scitotenv.2021.146267 Interpretive Summary: Repeated application of poultry litter (PL) results in buildup of soil phosphorus (P), and its movement to water bodies can lead to eutrophication. The primary objective of this study was to identify and quantify major forms of P in PL impacted Alabama soils with different soil test P (STP) ratings and determine their agronomic and environmental impacts. Phosphorus fractionation method was utilized to quantify labile P, Fe-Al P, humic-fulvic P, Ca-Mg P, and residual P fractions as well as STP ratings. The environmental risk of P loss was determined using the concept of soil P storage capacity (SPSC). Large amounts of P added via PL was adsorbed in the surface soils and remained in moderate to stable P forms which can potentially be available for plant uptake or runoff. However, most of the subsurface soils would potentially need P fertilization to sustain the plant P demand. Technical Abstract: Repeated application of poultry litter (PL) results in buildup of soil phosphorus (P), and its movement to water bodies can lead to eutrophication. Agronomic P needs and environmental P loss risk must be evaluated for PL impacted Alabama soils that are highly weathered, widely P limiting, and have high P fixation capacity. The primary objective of this study was to identify and quantify major forms of P in PL impacted Alabama soils with different soil test P (STP) ratings and determine their agronomic and environmental impacts. Phosphorus fractionation method was utilized to quantify labile P, Fe-Al P, humic-fulvic P, Ca-Mg P, and residual P fractions. Labile P fraction was found minimal for all soils irrespective of STP ratings. The environmental risk of P loss was determined using the concept of soil P storage capacity (SPSC). Surface soils (0-0.15m) had greater risk of P loss during storm events (mean SPSC < 0) whereas subsurface soils (0.15-0.30m) had capacity to retain additional P (mean SPSC > 0). The residual P fraction in soils decreased significantly when SPSC changed from positive to negative with a corresponding increase in moderate to stable P fractions (Fe-Al P, Ca-Mg P, and humic-fulvic P). Large amount of P added via PL was adsorbed in the surface soils and remained in moderate to stable P forms which can potentially be available for plant uptake or runoff. However, most of the subsurface soils would potentially need P fertilization to sustain the plant P demand. |