Abstract
South Florida and much of the rest of the World suffers from harmful algal blooms (HABs) and controls of both nitrogen (N) and phosphorus (P) pollution are required to curtail the onset, spread and/or expansion of these blooms.
 
 This report covers our studies on several aspects of equestrian waste (viz. horse manure) aimed at yielding an overview of phosphorus and its pollution stemming from non-point horse manure sources in portions of Palm Beach County Florida. Methods included a modified Hedley extraction sequence, emphasizing ‘easily extractable phosphorus’ (EEP), and 31P nuclear magnetic resonance (NMR) spectroscopic identification of organic phosphorus (Po) species.
 
 Samples included fresh and aged horse manure, pasture soils, horse feed and pasture grasses, and canal waters adjacent to equestrian or agricultural fields.
 
 Easily extractable Phosphorus (EEP) averaged about 54-77% of the total horse manure phosphorus. Total phosphorus ranged from 13,020 – 22,300 mg per kilogram dry weight. (≈60-100 lbs. P2O5 / ton and on a wet weight basis, this equates to 4,000 to 14,818 grams-P/ U.S. ton or 8.8 to 32.6 pounds of phosphorus (≈ 20-75 lb. P2O5) per wet weight ton of horse manure. Considering the values of EEP in fresh samples from a single horse, we found a range of 8,000 – 17,000 mg-P/kg (8-17 g-P/kg) dry weight horse manure.
 
 Soil samples yielded the highest P in the NaOH extract of the Hedley sequence. This equates to the Al, Fe and ester forms. 
 
 Phosphorus (viz. EEP) runoff is viewed here as a non-point P pollution source.
Highlights
The pollution of surface waters with primary plant nutrients, notably nitrogen and phosphorus, is increasing worldwide (Carpenter et al, 1998; Elser et al, 2007; Guignard et al, 2017; Smith et al, 1999)
An additional feed sample (Nutrena Proforce Senior®) was analyzed in triplicate only for total phosphorus using ICP-OES and it was found to have 6,340+ 300 mg/kg-P, dry weight. Given that this was a limited sample of horse feeds, Total phosphorus (TP) can be noted to range from about 6,000 – 11,000 mg-P (611 g-P; 0.6 -1.1%) per kilogram of various feed materials. 3.1.5 Horse paddock soil phosphorus with depth Certain manure samples (“CC”) were taken from a horse field where we investigated phosphorus quantity and fractions versus soil depth
The extremely high soluble reactive P (SRP), aka extracted phosphorus (EEP), concentrations found in horse manure, shown in Tables 2-3, leads to large amounts of P pollution from water runoff
Summary
The pollution of surface waters with primary plant nutrients, notably nitrogen and phosphorus, is increasing worldwide (Carpenter et al, 1998; Elser et al, 2007; Guignard et al, 2017; Smith et al, 1999). Vol 10, No 2; 2021 tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged. This term does not include agricultural stormwater discharges and return flows from irrigated agriculture.” (USEPA, 2019)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
