UTILIZATION OF WASTEWATER RESIDUALS IN SOD BASED ROTATIONS M. B. Adjei and J.E. Rechcigl

1. UTILIZATION OF WASTEWATER RESIDUALS IN SOD BASED ROTATIONS M. B. Adjei and J.E. Rechcigl

2. Objective Evaluate effect of N source by rate on bahiagrass forage production, and associated groundwater and soil chemical changes.

3. Environmental Concerns • Potential for spread of pathogens • Accumulation of heavy metals • Nutrient loading and pollution 3b Organic contaminants (dioxin, brominated flame retardants, alkylphenol ethoxylates) • Odor

4. Materials & Methods • Randomized complete block design with three replicates • 9 Fertilizer treatments: • Sources: (4) • Ammonium nitrate • Liquid sludge pH 7 • Liquid sludge pH11 • Lime stabilized cake biosolid • Control

5. Materials & Methods contd. • Fertilizer rates: • 0 lb/A (Control) • 80 lb/A • 160 lb/A • Fertilizer application: • Applied July 1997 during bahiagrass plot establishment. • Repeated on same plots in April-May, 1998. • Repeated on same plots in March 1999, 2000.

6. Field Layout

7. Sewage Sludge Facility

8. Types of cake biosolids

9. pH, Coli, Nutrients

10. Metals

11. Sludge Application

12. Groundwater Sampling

13. Water sample processing • Determine pH and Conductivity • Acidify to pH<2 • P, & trace metals ( nitric acid) • N fractions (conc. H2SO4) • immediately froze samples until analyzed

14. Fertilizer Treatments • 1) Ammonium nitrate: 80 lb/A(AML) • 2) Ammonium nitrate: 160 lb/A(AMH) • 3) Liquid sludge pH 7: 80 lb/A (LS7L) • 4) Liquid sludge pH 7: 160 lb/A (LS7H) • 5) Liquid sludge pH 11: 80 lb/A (LS11L) • 6) Liquid sludge pH 11: 160 lb/A (LS11H) • 7) Cake biosolid: 80 lb/A (CBL) • 8) Cake biosolid: 160 lb/A (CBH) • 9) Control 0 kg lb/A (CONT)

15. Measured Variables • Forage: • (DMY, CP, Tissue minerals) • Groundwater: 2ft vs. 4ft wells • (pH, NaCl, Trace metals, Plant nutrients) • Soil: 3 depths • (pH, Trace metals, Plant nutrients)

16. Survey of groundwater quality • 3 county sites: Desoto, Hardee, Manatee • 3 treatments: • Control • Ammonium nitrate (80 lb/A) • Sludge/biosolid (80 lb/A) • pH, trace metals & plant nutrients

17. Results • Forage measures • Yield • CP, IVOMD • Nutrient uptake (N, P, K Ca, Mg, Fe, Zn, Cu, Mn) • Groundwater • pH, NaCl • Trace metals (Ba Cd Ni Pb) • Plant nutrients (P NO3) • Soil (Zn & Mn accumulated under LS7-160)

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23. Effect on Forage Nutrient Concentrations (mg kg-1)

24. Groundwater

25. Effect on Groundwater pH, Na & Cl (ppm)

26. Effect on Groundwater Trace Metal concentrations (ppm)

28. Effect on Groundwater N

32. Conclusions • Forage yield and quality were similar for liquid sludge and ammonium nitrate. • Greater forage uptake of P, K, Ca, Fe from sludge sources of fertilizer ‘cause of greater nutrient availability & improved soil pH. • P concentration in groundwater not affected by N-source but 10 times higher (3 ppm) above than below (0.3 ppm) the spodic horizon .

33. Conclusions Contd. • Trace metal concentrations were negligible. • Spikes of NO3 in surface groundwater exceeding 10 mg L-1 occurred in shallow wells within 60 d period of grass establishment following ammonium nitrate application and also at Dump site.

34. Conclusions contd. • Tendency for pH and P to increase in soil from repeated use. Sod based rotations will provide the needed break. • Supplemental K and Mn may be needed. • Wastewater residuals could be an inexpensive and safe alternative N-source for sod based rotations if used judiciously.

35. Acknowledgment • Authors acknowledge with thanks the financial support provided by the FDACS- NBMP Program & the USDA Smith-Lever Water Quality Extension Award.