1. Cranberry Station Phosphorus in Cranberry Nutrient Management Carolyn DeMoranville UMass Cranberry Station

2. 2 Cranberry Station Why is this important?

3. 3 Cranberry Station What have we done? Plot scale work to define P requirement – >0 but <22 kg Field-scale: Enlist growers to reduce well below 22 kg/ha (‘not to exceed’ level) Collect data from their farms – Crop yield – Tissue P – Water quality Use these data to make the case for others to adopt reduced P

4. 4 Cranberry Station Results of surveys conducted in January 2008 (2007 season); January 2009 (2008 season); March 2010 (2009 season). season Management choice200720082009 N:P P>N36%15% N:P P no more than N34%61% Plan to reduce P use next season36% Reduced P use51%65%

5. 5 Cranberry Station Grower P reduction sites study P rate in kg/ha Site # P applied 2008 P applied 2009 P applied 2010 P applied 2011 P applied 2012 16.68.410.012.310.9 28.59.9 8.2 11.28.2 3 0.70.90.87.5 48.74.110.24.96.8 5--8.65.68.316.0 614.18.58.4

6. 6 Cranberry Station Through 2012 season

7. 7 Cranberry Station Data from 2005-2011

8. 8 Cranberry Station Standard range = 0.1 – 0.2% Tissue P % dry weight Site Avg. kg/ha P20082009201020112012 18.30.13 0.120.130.10 28.80.16 0.090.160.13 32.70.130.150.110.150.11 47.00.150.160.130.160.12 57.5 0.140.110.120.13 610.3 0.14 0.12

9. 9 Cranberry Station Comparison of TP in flood releases Years of P reduction Site200920102011 1789 2567 3234 4234 5123 6345

10. 10 Cranberry Station Harvest flood P concentrations

11. 11 Cranberry Station Winter flood P concentrations Note: scale is 10x less than for harvest flood

12. 12 Cranberry Station Harvest flood 1 acre-foot = 1233 m 3 1 lb = 0.45 kg

13. 13 Cranberry Station Change (kg/ha released) HarvestWinter Year 12.921.77 Year 70.48--- Year 80.680.20 Year 90.510.19 Applied P Pre-2003 = 22 kg/ha Avg. starting 2003 = 11 kg/ha Site 1

14. 14 Cranberry Station Potential impact  Site 1  Bog is ~25 ha  In 2003, the 2 floods (winter/harvest) contained 117 kg P  8 years later, the floods contained 17 kg P  85% reduction

15. 15 Cranberry Station Next steps  Continue and expand monitoring study, recruit growers to use 5 kg/ha P  Large grant to begin to install and evaluate methods to remove or minimize P from discharge water – filters, other BMPs

16. 16 Cranberry Station Questions?

17. Cranberry Bog Total Phosphorus CES/SMAST Field Expt. TP Fertilization (kg/ha/yr) TP incoming (kg/ha/yr) TP leaving (kg/ha/yr) TP export (net) (kg/ha/yr) Bog ID Mean 2003-04 EH 11.2 0.34.54.2 PV 22.2 1.88.56.8 BEN 18.8 1.23.92.7 WS 19.6 0.25.55.3 M-K 23.1 2.03.21.2 ASH 39.3 1.83.41.7 Mean22.41.224.833.65 A Flow-through Bog was found to have a higher annual TP loss of 9.9 kg/ha/yr (Howes & Teal 1995)

18. 18 Cranberry Station Yield (Mg/ha) comparison of 4 or 6 years prior to that in 2008-2011 Site P 2008-2011 (kg/ha/yr) 4 years prior yield 6 years prior yield 2008-2011 average 1 8.3*17.123.9 2 8.8*17.425.8 32.712.914.4 47.019.923.4 6 7.5**? 22.3** 710.3*17.4 18.0* **2009-2011*2008-2010