Using Paired Edge of Field Data to Assess Impacts of Management on Surface and Subsurface P Loss

Transcription

1 Using Paired Edge of Field Data to Assess Impacts of Management on Surface and Subsurface P Loss Kevin W. King, Mark R. Williams, and Norm R. Fausey USDA ARS Soil Drainage Research Unit Columbus, OH

2 Edge-of-field research 40 fields (20 paired fields) representative of Ohio crop production agriculture Surface runoff and tile discharge measurements Using a before-after controlimpact study design

3 Funding Sources: 4R Research Fund USDA ARS: USDA Agriculture Research Service CEAP: Conservation Effects Assessment Project EPA: DW Ohio Agri Businesses Ohio Corn and Wheat Growers CIG: 69 3A (OSU) CIG: 69 3A (Heidelberg University) MRBI: Mississippi River Basin Initiative The Nature Conservancy Becks Hybrids/Ohio State University Ohio Soybean Association

4 Phosphorus Concentrations surface tile Event mean concentration (mg/l) DRP TP

5 Annual DRP loading (kg/ha/yr) Annual TP loading (kg/ha/yr) Tile Surface P Tack Force recommendation A B C D E F G H I J K L M N O P Q

6 Effect of event size on surface losses 0.8 Discharge rainfall events greater than 6.3 mm (0.25 inches) Fraction of Annual DRP TP Across all sites, rainfall events > 50.8 mm (2 inches) accounts for: 10.2% of all rainfall events 65% of discharge % of DRP load % of TP load < > 88.9 Event Size (mm)

7 Effect of event size on tile losses Discharge 1601 rainfall events greater than 6.3 mm (0.25 inches) 0.2 Fraction of Annual DRP TP Across all sites, rainfall events > 50.8 mm (2 inches) accounts for: 6% of all rainfall events 45% of discharge % of DRP load % of TP load < > 88.9 Event Size (mm)

8 4R Preliminary Findings Rate Timing Source Placement

9 Fertilizer Rate

10 Fertilizer Rate Mehlich 3 STP (ppm) Discharge:Precipitation Ratio <0.3 kg/ha >0.3 kg/ha tri-state critical level tri-state maintencance level

11 Discharge (m3/s) discharge NO3 + NO2 - N (mg/l) DRP (mg/l) 0 3/1/15 4/1/15 5/1/15 6/1/15 7/1/15 8/1/15 Data from Heidelberg Univ. Laura Johnson

12 Timing

13 180 Surface Losses Time of Application kg/ha 0.56 kg/ha 0.50 kg/ha Greatest potential for surface and tile losses occurs with fall and winter application Mehlich 3 STP (ppm) kg/ha Tile Losses 0.50 kg/ha Applying P in spring or after wheat harvest seems to minimize surface and tile losses Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Time of application

14 20 DRP concentration (mg/l) /3/12: 225# MAP 11/13/13: 193# MAP Days since application

15 Placement

16 Broadcast variable rate application on May 6, 2014

17 4 part stratification M3P (ppm) Core depth (inches) Median Stratification evident even in the top 1 of soil (ANOVA, P<01, n=232) Although the degree of stratification varied some 85% of the samples had some degree of stratification Source: Johnson and Baker, Heidelberg University

18 Before P application & tillage (April 28 th ) After P application & tillage (May 12th) Discharge (mm) TD1 Discharge Preferential flow DRP TD Discharge DRP TD Avg DRP (mg/l) = 8 Avg DRP (mg/l) = 8 Avg DRP (mg/l) = 0.58 Avg DRP (mg/l) = 2.12 DRP (mg/l) DRP (g/ha) TD DRP (mg/l) DRP (g/ha) DRP Load (g/ha) = 12.6 DRP Load (g/ha) = 12.4 DRP Load (g/ha) = 18.2 DRP Load (g/ha) = 129.6

19 Fertilizer Source

20 Fertilizer Source (chronic vs acute risk) DRP Load (kg/ha) DRP NO3-N Load (kg/ha) NO3-N inorganic mixed organic

21 Structural and Other Management Drainage Water Mgt Gypsum Cover Crops

22 Drainage Water Management Quantify tile discharge and nutrient dynamics before and after implementation of drainage water management

23 DWM - Case Study Drainage area: B2 = 14 ha; B4 = 15 ha m Legend Tile depth: m Ohio Ditch Tile outlet Drainage area Soil type: Bennington silt loam Pewamo clay loam Upper Big Walnut Creek Watershed B2 B4 Soil test P concentration: 60 mg/kg (0-20 cm) : Both sites were free draining : DWM was implemented at B4

24 DWM - Case Study Mean DRP conc. (mg L -1 ) 0.30 B B Annual DRP load (kg/ha) Year Year DWM did not significantly affect DRP concentration 65-74% reduction in annual DRP load with DWM

25 Gypsum Treatment Mercer County Ohio >400 ppm Mehlich 3 in the top 8 inches Corn soybean rotation in a no till system Blount soil; randomly tiled June 2011 to October 2014 October 3 of 2013, 1 ton of gypsum was applied to treatment area Baseline period (86 rainfall events ) Treatment period (34 rainfall events)

26 Surface Tile Combined Treatment field DRP concentration (mg/l) DRP load (kg/ha) TP concentration (mg/l) kn4-tp-cnc-c vs kn1-tp-cnc-c kn4-tp-cnc-t vs kn1-tp-cnc-t xp vs surf TP conc c xp vs surf TP conc t Gypsum effect on surface drainage and P Significant increase in tile drainage discharge Significant decrease in DRP and TP event concentrations Significant decrease in DRP and TP loading TP load (kg/ha) kn4-tp-ld-c vs kn1-tp-ld-c kn4-tp-ld-t vs kn1-tp-ld-t xp vs surf TP load c xp vs surf TP load t Control field

27 Cover Crops (what is the resource concern?) Positives Increase infiltration Reduce erosion Improve soil health Increase OM Negatives Increase DRP surface losses following freeze thaw cycles (Miller et al., 1994; Bechmann, et al 2005; Cavadini, 2013) Leachate concentrations of P differ depending on catch crop and soil (Riddle and Bergstrom 2013; Liu et al 2014) P concentration around tuber of tillage radish significantly greater than surrounding soil (White and Weil, 2011)

28 Conclusions P & N losses are impacted by: STP Connectivity to water Placement of P fertilizer Timing of fertilizer Rate of fertilizer Source and legacy effects

29 Conclusions Practices that will address excess P Adherence to tri state recommendations or lesser application Increased organic matter/carbon, cover crops, no till, etc Cover crops correct cover crop or blend is critical Gypsum water quality benefits are minimal but significant Avoiding fall and winter applications Accounting for manure in nutrient calculations Subsurface placement of nutrients (banding or injecting) Disconnecting hydrologic pathways (DWM, blind inlets, linear wetlands, water storage/increased OM)

30 Collaborators, Partners, and Outreach SWCDs OSU Extension and OARDC Agri businesses (Commodities, retailers) Ohio Farm Bureau TNC State agencies (ODNR, ODA, OEPA) NRCS (local, state, and federal) Crop consultants Producers/landowners Lake Improvement Other ARS locations NOAA and NWS Great Lakes Commission Great Lakes Protection Fund Greenleaf Advisors Multiple University Partners (OSU, Utoledo, Oklahoma State Univ., Univ. of Waterloo, NC State, Purdue Univ.) 4R Research Fund (IPNI, TFI) NCWQR at Heidelberg Agriculture and Agri Food Canada Consultants (CCAs, Limno Tech) USGS Private Industry (Agri Drain, ADS, Hancor, John Deere, The Andersons, Becks Hybrids) Gypsoil

31 Technical Support Staff Mark Day, Eric Fischer, Phil Levison, Paxton MacDonald, Katie Rumora, Marie Schrecengost, Jed Stinner Contact Information Kevin King 590 Woody Hayes Dr. Columbus, OH