Phosphorus for the Ontario CCA 4R Nutrient Management Specialty

Transcription

1 Ontario CCA 4R Nutrient Management Workshop Wednesday, 18 January 2017 Woodstock, Ontario, Canada Phosphorus for the Ontario CCA 4R Nutrient Management Specialty Tom Bruulsema, Phosphorus Program Director

2 Lake Erie - 20 July 2016

3 4R: right means sustainable

4 Nutrient Stewardship Metrics for Sustainable Crop Nutrition Enablers (process metrics) Outcomes (impact metrics) Extension & professionals Infrastructure Research & innovation Stakeholder engagement Actions (adoption metrics) Cropland area under 4R - requires regional definition of 4R 1. Farmland productivity 2. Soil health 3. Nutrient use efficiency 4. Water quality 5. Air quality 6. Greenhouse gases 7. Food & nutrition security 8. Biodiversity 9. Economic value

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6 4R Adaptive Management for Plant Nutrition Policy Level Regulatory, Infrastructure, Product Development Regional Level Agronomic scientists, Agri-service providers Farm Level Producers, Crop advisers DECISION SUPPORT based on scientific principles Recommendation of right source, rate, time, and place (BMPs) DECISION Accept, revise, or reject ACTION Change in practice EVALUATION of OUTCOME Cropping System Sustainability Performance LOCAL SITE FACTORS Climate Policies Land tenure Technologies Financing Prices Logistics Management Weather Soil Crop demand Potential losses Ecosystem vulnerability

7 III Phosphorus starting page 78 in the Guide Performance Objective 1: Discuss the most common sources of phosphorus used in Ontario. MAP DAP APP TSP Biosolids Manure (Chris Brown and Trevor Robak)

8 Fertilizer P is Soluble P MAP ( ) has water solubility of 370 g/l = 84,000 mg P per litre In the soil solution, crops require 0.1 to 0.3 mg P per litre Maumee river target for DRP = mg P per litre

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11 Concentrated Superphosphate (Triple superphosphate) Contains 46% P 2 O 5 P 2 O 5 4R PNM 3-20

12 Biosolids 1. Amount of P in biosolids is roughly equal to dietary P supply. 2. Total biosolids from sewage treatment in North America contains an equivalent of 8% of crop P removal. 3. Currently, half the biosolids are land applied, to less than 1% of the cropland. 4. Good source of zinc. 5. Low analysis sources: 1. Issues with bulk and transportability. 2. Accuracy of reported nutrient analysis guaranteed minimum does not apply well to bulk materials

13 Struvite crystallization is promising technology nutrient rich streams mixed with MgCl in a controlled chemical precipitation Precipitation reaction: Mg +2 NH 4+ PO 4-3 Removes up to 90% P and 20% N Low salt index and low heavy metal content Produces a slow-release N, P and Mg fertilizer Ostara Technology Crystal Green Mg

14 Performance Objective 2: Discuss considerations to determine the right source of phosphorus based on: crop type and cropping system; climate (temperature, precipitation, leaching, and runoff patterns); soil texture and the effect of soil ph; environmental concerns in the local area (surface and groundwater); crop stage.

15 Performance Objective 3: Interpret how soil test phosphorus levels relate to crop yield response and potential environmental impacts.

16 Soil test P and runoff P in Ontario STP DRP Six soil series, ten sites each, ranging in soil test P. Standardized runoff boxes, rainfall applied at 3 per hour for 30 minutes runoff. Wang et al., J. Environ. Qual. 39:

17 Soil test P and P leaching through Ontario soil columns

18 Ontario soil test P distribution 60% 40% 2001: 25% 16% 59% 20% 2015: 36% 19% 44% 0% >38 Soil Test P (Olsen), ppm

19 Phosphorus legacy differs by region (11) (23) (38) (Olsen)

20 Performance Objective 4: Evaluate how different soil test phosphorus extraction methods affect the interpretation of crop yield response and potential environmental impacts.

21 Soil test P extractants differ chemically

22 Ontario Soil Test P calibration 100% Relative yield 90% 80% 70% 60% Soil test P (ppm Olsen)

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24 Australia Better Fertilizer Decisions for Crops

25 Performance Objective 5: Estimate the environmental risk of applying phosphorus above crop response optimums. Increases soil test P Risk can be assessed by Ontario P Index in NMAN Risk depends on placement, current soil test P, soil hydrology, slope, etc.

26 Performance Objective 6: Justify the considerations for phosphorus application rate based on: soil characteristics including leaching; topography and runoff; crop conditions, crop type, and growth stage. Sandy soils that leach N may not leach P P leaching generally only in P-saturated soils Macropore flow from surface to tile can deliver P Topography, soil texture influence runoff and erosion Match crop condition to expected removal Most P applied pre- or at planting. Exceptions: potatoes, forages.

27 Performance Objective 7: Calculate phosphorus credits from: previous phosphorus application Current STP = old STP + (P balance/25) [25 may be 37 or 50 depending on soil] Manure OMAFRA Pub 811: P2O5 = 2.29*P; available P = 40% of total P biosolids and other organic amendments NASM plan Limitations of minimum guarantee for registered products Wastewater Analysis for P Greenhouse nutrient feedwater O. Reg 300/14 OMAFRA, 2016

28 Performance Objective 8: Justify the potential need to adjust the phosphorus application rate based on legacy phosphorus and application method. Legacy P = that which has accumulated as a result of past human activity Reflected in soil test P Also present in stream banks and river sediments Application method: maximum safe rates for band-placed or in seed row.

29 Performance Objective 9: Discuss the importance of the following on phosphorus application timing: intensity of precipitation; type of precipitation; duration of precipitation; runoff. Broadcast applications of phosphorus sources should be avoided when substantial rainfall is imminent or forecast to occur before the material can be incorporated into the soil Late summer early fall Frozen or snow-covered soil

30 Performance Objective 10: Discuss the mechanisms of phosphorus loss to surface water. Particulate Soil erosion, from cultivated (tilled) fields Dissolved Surface runoff, from grass forest, or no-till soils

31 Performance Objective 11: Discuss reduction strategies and management for particulate phosphorus loss. Control soil erosion Prevent excessive buildup of soil test P Ontario P Index RUSLE 2.0 for Ontario - Agren s SoilCalculator - Sandra Cooke (Conservation Ontario) and Kevin McKague (OMAFRA)

32 12. Discuss reduction strategies and management for dissolved phosphorus loss. Manures and fertilizers contain soluble P. In contact with soil, soluble P is adsorbed, precipitated, retained. Without soil contact, soluble P dissolves in rainwater. Runoff risks vary with season Lower risk applying in late summer or early fall Cover crops, tillage and soil compaction can be managed to increase infiltration Drawdown of soil test P Drainage water management

33 13. Right Time Discuss how phosphorus contamination of surface water can occur from tile drainage due to timing of application. Macropores Cracking in clay Earthworm channels Bypassing the matrix Minimal sorption of dissolved P Avoid broadcasting P when there is >50% chance of intense rain

34 Less P is lost with more time between broadcast and runoff Concentration of dissolved P in surface runoff from plots cropped to tall fescue during rainfall simulations that occurred 1 to 29 days after broadcast application of triple superphosphate fertilizer (Smith et al., 2007).

35 14. Right Place Discuss the importance of the following climate and weather phenomena to determine the optimal placement or method of application of phosphorus: a. intensity. b. type of precipitation. c. duration of precipitation. d. runoff.

36 Placing P in the soil reduces P loss from a single immediate runoff event Concentration of dissolved and total P in runoff from a clay loam soil in North Carolina, from artificial rainfall immediately following application of superphosphate fertilizer. Incorporation was to a depth of 5 inches by rotary tillage following application. Data from Tarkalson and Mikkelson (2004).

37 15. Discuss the relationship between tillage practices/system on phosphorus management. Stratification Mycorrhizae Soil temperature and moisture

38 Soil test P stratification Interaction of conservation tillage and right place samples M3P (ppm) :1 line Core depth (inches) Top M3P (0-2", ppm) :1 line 5-8 Dr. Laura T. Johnson, Heidelberg University, Ohio, USA Total M3P (0-8", ppm)

39 16. Discuss the considerations for phosphorus placement and method of application based on the risk of phosphorus runoff. Broadcast Incorporated Banded Spatial variability Agronomic Environmental Logistical

40 17. Plan the best placement or application method for phosphorus to minimize the transport of phosphorus offsite. 4R principles for right place Source, rate, and time Where are the roots? Concentrate to overwhelm soil sorption Erosion control by no-till Spatial variability Planning 1. Sustainability goals 2. Information 3. Field-specific plans 4. Implement 5. Monitor for effectiveness

41 18. Discuss how phosphorus contamination of surface water can occur from tile drainage due to placement and method of application. Acute risks: Phosphorus on the surface the first to come in contact with rain Liquid manure with large volume of water Chronic risk: conservation tillage and stratification. In both cases, water enriched in P can move through macropores to tile drains. Macropores: cracks, or earthworm channels

42 19. Discuss how to use drainage water management to reduce phosphorus nutrient losses to surface water Controlling the level of the soil water table Reduces total water drainage May increase or decrease dissolved P concentration Generally decreases loss 10-15% if combined with subirrigation (requires retention pond) Requires flat fields with minimal slopes.

43 20: Discuss how to use water quality vulnerability assessment tools on a site specific basis for phosphorus nutrient planning. 22 source water protection plans in Ontario Risk management zones Restrictions on animal penning, manure storage, fertilizer use NMPs may be required or encouraged

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45 Takes effect July

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48 21. Evaluate phosphorus management decisions using a water quality vulnerability assessment Phosphorus Index USLE A = R x K x LS x C x P Water runoff class Soil hydrological group Max field slope within 150 m of surface water Soil test P Fertilizer rate and method Manure rate and method Application rate In relation to crop removal Setback distance

49 Ontario Phosphorus Index Phosphorus Index for Site < > 50 Generalized Interpretation of Phosphorus Index for Site Minimum Setback 1 from Surface Water if P 2 O 5 is applied up to crop removal 2 [ft (m)] Minimum Setback from Surface Water if P 2 O 5 is applied over crop removal [ft (m)] Very low potential for P movement from the site. If farming practices are maintained at the current level there is a small chance that P losses from this site will have an adverse impact on surface waters. 10 (3) 100 (30) Low potential for P movement from the site. The chance for an adverse impact to surface water exists. Some remedial action should be taken to lessen the potential for P loss if application is close to surface water. 10 (3) 100 (30) Moderate potential for P movement from the site and for an adverse impact on surface waters to occur unless remedial action is taken. In areas close to surface water, soil and water conservation along with P management practices are needed in order to reduce the risk of P movement and water quality degradation. 10 (3) 200 (60) High potential for P movement from site and for an adverse impact on surface waters. Remedial action is required to reduce the risk of P movement. All necessary soil and water conservation practices plus a P management plan must be put in place to avoid the potential for water quality degradation. 100 (30) Do not apply over crop removal

50 22. Be able to evaluate how changing a specific phosphorus management strategy will affect the outcome of a risk assessment Site Characteristic Soil Erosion Water Runoff Class Phosphorus Soil Test Management Practices that will Lower P Index Any practice to reduce soil erosion. In some instances, tile drainage installation may change the effective soil hydrologic group rating. The management of fertilizer and manure application methods/rates will control the rate at which the phosphorus level in the soil changes. Example of BMPs Reduce slope length; tillage to increase surface residue; plant cover crops; crop rotation, strip cropping, contour tillage. Tile drains may reduce runoff water volumes and thus lower risk of P loss in surface runoff. They also increase risk of P loss through tile drains by increasing connectivity. The phosphorus level of a field can be lowered on a long-term basis by reducing or eliminating application rates of manure/fertilizer and/or using crops with higher P removal capabilities.

51 Site Characteristic Commercial Fertilizer Application Rate Commercial Fertilizer Application Method Manure /Biosolid Application Rate Manure /Biosolid Application Method Management Practices that will Lower P Index Applying less fertilizer to a field will lower the level of phosphorus accordingly. The use of an application method that incorporates the fertilizer quickly and efficiently will result in a lower rating factor. Applying less manure to a field will lower the level of phosphorus accordingly. The use of an application method that incorporates the manure quickly and efficiently will result in a lower rating factor. Example of BMPs A reduction in the commercial fertilizer application rate from 60 lbs P 2 O 5 /acre to 30 lbs P 2 O 5 /acre will reduce the P Index by 1 point. By changing the application method from Non-Incorporated to Placed with Planter, the P Index is reduced by 10.5 points. A reduction in the manure/biosolid application rate from 60 lbs P 2 O 5 /acre to 30 lbs P 2 O 5 /acre will reduce the P Index by 3 points. Changing the application method from Non-Incorporated on Bare Soil to Injected will cause the P Index to be reduced by 10.5 points.

52 23. Evaluate management strategies, including modifying phosphorus transport processes, which will reduce phosphorus loss to surface water and groundwater Tile drainage Grassed borders and waterways Terraces WASCoBs water and sediment control basins Buffer strips Cover crops Furrow management Wetlands

53 24: Discuss how tillage system (including no-till) affects environmental losses of phosphorus. Tillage Acute effects reflected in Ontario P Index (USLE) Chronic effect of stratification is not

54 25: Compare the differences in the geographic scale, soil, topography, and location of watersheds (e.g. national, regional, local) on the environmental impacts of phosphorus on surface and groundwater resources. Scale streams, ponds, reservoirs, large rivers, lakes Soil texture & risk of runoff Topography Location (region)

55 26. Discuss the role of phosphorus, including legacy phosphorus, in the eutrophication process and the potential consequences of eutrophication Eutrophication Harmful algal blooms Hypoxia Legacy from past human activities Nutrients, land, water flows

56 Summary Sustainable Phosphorus Management 1. Key Challenge: Increasing BOTH crop productivity AND water quality 2. 4R Nutrient Stewardship It s not only up to scientists It s not only up to producers, advisers and ag retailers We all play a role 3. 4R Phosphorus Research Options available for source, rate, time and place, but practice change depends on quantified impacts Research continuing on edge-of-field impacts