Determination of Some Key Factors for Ontario Soil P Index and Effectiveness of Manure Application Practices for Mitigating Risk to Water Resource

Transcription

1 Determination of Some Key Factors for Ontario Soil P Index and Effectiveness of Manure Application Practices for Mitigating Risk to Water Resource Project: NM8002 T.Q. Zhang Greenhouse & Processing Crops Research Center, Agriculture & Agri-Food Canada, Harrow, ON

2 NM8002 team Collaborators Dr. Q.C. Hu Mr. Y.T. Wang Dr. C.S. Tan Dr. I. O Halloran Dr. C.F. Drury Mr. K. Reid Dr. B. Ball-Coelho Dr. B.L. Ma Mr. T.W. Welacky Mr. G. Patterson Dr. W.D. Reynolds OMAFRA nutrient management staff Selected Ontario crop and animal farmers Technicians Ms. M.R. Reeb Mr. B. Hohner Mr. D. Pohlman Mr. K. Rinas Mr. V. Bernyk Ms. R. Pararajasingham Ms. K. Henning Mr. L. Evenson Mr. R. Stone

3 Connection to NMJRP The P index, with specific contributions to development of an environmental soil P test (ESPT) for Ontario soils determination of manure P source coefficients (PSC) Soil P losses Surface runoff flow Subsurface flow - leaching water

4 Objectives To evaluate the suitability of current agronomic soil P test (Olsen P) as an indicator of soil P level s environmental risk, and eventually to develop a ESPT for Ontario soils To determine P source coefficients (PSC) (weighing factor) of major types of manures in Ontario to indicate the risk of P movement after application

5 Setting the stage Collection of soil samples across the province was desired to represent the predominant soil types distributing in the major manure production areas of Ontario to cover a great range of soil chemical and physical properties to cover a great range of soil test P levels, from highly responsive to non responsive, within each soil type

6 Setting the stage good knowledge of recent history of farming practices for the selected sampling sites soil sampling at least one year after fertilization, to avoid possible P losses directly from newly applied fertilizer and manures In addition, largely increased sampling sites covering majority of soil types distributing in agricultural production areas for validation purpose

7 Setting the stage Collection of manure and biosolids samples across the province was desired to represent the major types produced in Ontario to reflect potential variation within the same manure or biosolids type Manure or biosolids application rate: representative of that made when applied to meet crop N needs

8 Study one: Development of environmental soil P test method (ESPT)

9 Methodology Soil sample collection: 60 sites 6 soil types: Fox sandy loam, Listowel silt loam, Grenville loam, Conestogo loam, Perth clay loam, Brookston clay 10 sites per soil type Soil test P (Olsen P): ppm Additional soil samples collected for validation study: 391 sites (118 reported at this stage)

10 240 intact cores 5.5 ton

11 Surface runoff box simulation study: - USEPA national P project method

12 Leaching study undisturbed soil core approach

13 Methodology 17 soil P tests evaluated as related to soil P losses via surface runoff and leaching 3 agronomic soil P tests: Olsen, Mehlich- 3 (M-3), Bray-1 14 environmental soil P tests or degree of soil P saturation (DPS): CaCl 2, Water, Fe-O strip, Oxalate P, DPS wep, DPS M-3-1, DPS M-3-2, DPS M-3-3, DPS M-3-4, DPS ox, DPS ol, DPS bray, DPS FeO, DPS CaCl2

14 Effectiveness of various soil P tests as indicators of surface runoff P loss Runoff DRP 30 (mg P L -1 ) y = x R 2 = 0.72** Runoff DRP 30 (mg P L -1 ) y = x R 2 = 0.89** Olsen P (mg P kg -1 ) WEP (mg P kg -1 ) Runoff DRP 30 (mg P L -1 ) y = x R 2 = 0.90** Runoff DRP 30 (mg P L -1 ) FeO-P < 45.3 mg kg -1 : y = x FeO-P > 45.3 mg kg -1 : y = x R 2 = 0.85** DPS M FeO-P (mg P kg -1 )

15 Effectiveness of various soil P tests as indicators of subsurface P loss Leachate DRP (mg P L -1 ) y = 5*10-6 x x R 2 = 0.53** Leachate DRP (mg P L -1 ) WEP < 0.283: y = x WEP > 0.283: y = x R 2 = 0.81** Olsen P (mg P kg -1 ) DPS M3-2 Leachate DRP (mg P L -1 ) WEP < 14.51: y=0.0233x WEP > 14.51: y = x R 2 = 0.82** Leachate DRP (mg P L -1 ) y = x R 2 = 0.78** WEP (mg P kg -1 ) DPS WEP

16 Relationships between soil test P and water extractable P ESPT validation y = x R 2 = 0.67** y = 38.72x R 2 = 0.89** WEP (mg P L -1 ) WEP (mg P L -1 ) Olsen P (mg P kg -1 ) DPS M3-3 WEP (mg P L -1 ) y = x R 2 = 0.77** WEP (mg P L -1 ) x < 40.1: y = x x > 40.1: y = x R 2 = 0.94** Mehlich-3 P (mg P kg -1 ) FeO-P (mg P kg -1 )

17 Summary - ESPT DRP concentration in both surface runoff and subsurface flow water increased with increases in levels of STP and DPS, respectively, in either linear or nonlinear manners Amongst the 17 soil P tests evaluated, DPS M3-2, DPS M3-3, and WEP demonstrated the highest R 2 values with soil P losses via both surface runoff and subsurface flow While the correlations are somewhat stronger with DPS M3 or the WEP tests than with the Olsen, the incremental value of changing from the Olsen has not been assessed

18 Study two: Determination of P source coefficients (PSC) for manures and biosolids

19 Methodology Indoor incubation 6 soil types 4 types of manure (liquid swine, liquid dairy, solid beef, solid poultry); 1 type of biosolids, with 3 sources each 1 inorganic fertilizer P, 1 zero-p control 4 incubation periods: 2 days, and 2, 8, and 26 weeks

20 Indoor incubation for determination of manure/biosolids PSCs

21 Field validation study on manure PSCs

22 Phosphorous source coefficients (PSC) of various manures in Ontario soils PSC (%) Liquid swine Liquid dairy Solid beef Solid poultry Manure type

23 Phosphorous source coefficient (PSC) comparisons between indoor and field incubation Indoor Field PSC (%) Liquid swine Liquid dairy Solid beef Solid poultry Manure type

24 Summary Manure PSC Mobility of P in soils after manure application varied, depending on the manure types Manure PSCs determined using the Mehlich-3 procedure were 117.4, 78.1, 58.2, and 53.6% for liquid swine, liquid dairy, solid beef, and solid poultry, respectively Biosolid PSC determined using WEP was 2.6% Cumulative effects of repeated manure application on PSC should be further determined with future work

25 Contributing to NM Science The current Ontario agronomic soil P test (Olsen P) did not predict soil P losses as precisely as DPS M3-2, DPS M3-3, and WEP Correlations between various soil P tests and P losses through runoff and leaching have been established across a wide range of soil types, and can be incorporated into the Ontario P index Manure PSC values varying substantially were determined for each specific types. Generic PSC values are currently used for manures in Ontario PSC value for one type of biosolids was determined

26 Contributing to NM Science The specific manure/biosolids PSC values can be used to increase the effectiveness of the Ontario P Index for assessing risk of soil P loss Research projects, that require intensive input (such as, in this project 11,200 samples were collected, and 39,000 analyses were performed) and extensive collaboration from governments, university, and stockholders, can only be made possible with public support, through both financial and in-kind contributions

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