Impacts of 4R Nitrogen Management on Drainage Water Quality

Transcription

1 Department of Agricultural and Biosystems Engineering College of Agriculture and Life Sciences Impacts of 4R Nitrogen Management on Drainage Water Quality Matthew Helmers Dean s Professor, College of Ag. & Life Sciences Professor, Dept. of Ag. and Biosystems Eng. Iowa State University

2 Soil Nitrate Production vs. Crop Nitrate Uptake Rate of soil nitrate production from native soil organic matter Rate of corn or soybean nitrate uptake The majority of nitrate used by corn and soybean comes from soil nitrate production. Corn gets the difference from fertilizer while soybean gets the difference from legume fixation of atmospheric nitrogen. March February In the shaded areas, the soil produces nitrate, but there is no crop to use it. As a result, some nitrate is lost to waterways.

3 Replicated subsurface drainage plots to evaluate performance of various in-field management practices NWRF Drainage Gilmore City DRF NERF Drainage COBS SERF Drainage 172 monitored plots ~4000 samples per year

4 Replicated subsurface drainage plots to evaluate performance of various in-field management practices NWRF Drainage Gilmore City DRF NERF Drainage COBS SERF Drainage

5 Twenty-Seven Year Summary Drainage (in) Drainage Nitrate-N Concentration Nitrate-N Loss Avg Nitrate-nitrogen Concentration (ppm) Nitrate-nitrogen Loss (lb-n/ac)

6 Twenty-Seven Year Summary Drainage (in) Drainage Nitrate-N Concentration Nitrate-N Loss Avg Combined Corn-Soybean System Same N management Early Spring Sidedress at lb-n/acre Nitrate-nitrogen Concentration (ppm) Nitrate-nitrogen Loss (lb-n/ac)

7 Nitrate Response to Nitrogen

8 Nitrate Response to Nitrogen

9 Results Nitrogen source Averaged over the corn-soybean rotation 25 Flow-weighted Nitrate-N Concentration (mg/l) Urea Aqua-Ammonia Poly-Coated Urea Avg

10 Impact of Application Timing: lb-n/acre 150 lb-n/acre

11 Impact of Application Timing: lb-n/acre 150 lb-n/acre

12 Soil Nitrate Production vs. Crop Nitrate Uptake Addition of a Cover Crop Rate of soil nitrate production from native soil organic matter Rate of corn or soybean nitrate uptake Cover crops can use nitrate when corn and beans are not growing, thus reducing the asynchrony between soil nitrate production and crop nitrate uptake. Cover crop nitrate use Cover crop nitrate use March February In the shaded areas, the soil produces nitrate, but there is no crop to use it. As a result, some nitrate is lost to waterways.

13 Winter Cereal Rye Cover Crops Ames Gilmore City

14 Impacts of Cover Crops on Nitrate-N Load in Drainage Water Gilmore City 36% Reduction 34% Reduction

15 Impacts of Cover Crops

16 Treatments at the Gilmore City Research Facility for Crop Years 2018-?. Treatment Number* 1,2 3,4 5,6 7,8 Tillage Cover Crop Nitrogen Application Time Conventional tillage Conventional tillage Conventional tillage Conventional tillage _ Rye planted into standing corn and beans and tilled prior to planting of cash crop in Spring Nitrogen Application Rate (lb/acre) Fall - Anhydrous 150 Fall - Anhydrous 150 with Inhibitor Spring - Anhydrous 150 Spring - Anhydrous 150 9,10 No-till _ Spring - Anhydrous ,12 No-till 13,14 15, Conventional tillage Conventional tillage Conventional tillage Orchardgrass + Red/Ladino clover Rye planted into standing corn and beans _ Spring - Anhydrous 150 Spring - Anhydrous 150 with Inhibitor Spring - Anhydrous 150 No N - no fertilizer

17 Replicated subsurface drainage plots to evaluate performance of various in-field management practices NWRF Drainage Gilmore City DRF NERF Drainage COBS SERF Drainage

18 Treatments Treatment Number Tillage Nitrogen Application Time 1 Conventional tillage* Fall (anhydrous ammonia with nitrapyrin)** 2 Conventional tillage Spring (anhydrous ammonia) 3 Conventional tillage Split with variable N at sidedress (40 lb/acre of urea 2x2 starter at planting plus in-season agrotain treated urea) Nitrogen Application Rate (lb N/acre)* Conventional tillage None 0 * Fall chisel corn stalks with spring disk/field cultivate, and spring disk/field cultivate soybean stubble. **In fall of 2014 freezing conditions occurred early and prevented fall application. Application occurred in early spring 2015.

19 Flow-weighted Nitrate-N Concentration *Means with the same letter in the same year are not significantly different, P=0.05.

20 Flow-weighted Nitrate-N Concentration *Means with the same letter in the same year are not significantly different, P=0.05.

21 Replicated subsurface drainage plots to evaluate performance of various in-field management practices NWRF Drainage Gilmore City DRF NERF Drainage COBS SERF Drainage

22 Impact of Land Management

23 Replicated subsurface drainage plots to evaluate performance of various in-field management practices NWRF Drainage Gilmore City DRF NERF Drainage COBS SERF Drainage

24 Treatments at the NERF Research Facility for Crop Years 2016-?. System Application timings and source of N Crop in Spring (UAN) Corn Soybean 2 Fall (early fall manure) Corn 3a 3b 4a Fall (manure w/instinct) Spring manure Fall (manure) Soybean Cont. Corn Cont. Corn Cont. Corn 4b Fall (manure) - gypsum Cont. Corn at 1 ton/acre 5 Fall (early fall manure) Corn/Rye cover Soybean/ Rye cover 6 Fall (late fall manure) Corn Soybean Tillage Chisel Plow Field Cultivate No-till No-till Chisel Plow Chisel Plow Chisel Plow Chisel Plow No Till No Till No Till No Till Nitrogen Application rate, lb/acre

25 Timing of Fall Manure Application Project Funded by: Iowa Pork Producers Association

26 To Reach our Goals WE NEED IT ALL!! N Management Cropping practices/landuse Edge-of-Field Practices

27 Department of Agricultural and Biosystems Engineering Resources 10 Ways to Reduce Nitrate Loss - content/uploads/2016/09/ten-ways-to-reduce- Nitrate-Loads_IL-Extension-_2016.pdf Drainage Water Quality Impacts of Various In-Field Nutrient Management Practices Agricultural Drainage Research and Demonstration Site Gilmore City AE 3614 Comparison of Biofuel Systems Site AE 3615 Northeast Research and Demonstration Farm AE 3616 Northwest Research and Demonstration Farm AE 3617 Southeast Research and Demonstration Farm AE 3618

28 Department of Agricultural and Biosystems Engineering Discussion Website:

29 Long-Term Trends

30 Relationship to Precipitation

31 Drainage as Function of Precipitation 30 Subsurface Drainage (in) Precipitation (in)

32 Nitrate-N Loss as Function of Precipitation 100 Nitrate-N Loss (lb/acre) Precipitation (in)

33 Nitrate-N Loss as Function of Drainage 100 Nitrate-N Loss (lb/acre) Drainage (in)

34 Nitrate-N Concentration as Function of Precipitation 25 Nitrate-N Concentration (mg/l) Precipitation (in)

35 Nitrate-N Concentration as Function of Drainage 25 Nitrate-N Concentration (mg/l) Drainage (in)

36 Temporal Changes

37 N Concentration Nitrate-nitrogen Concentration (ppm) Nitrate-N Concentration

38 N Loss 120 Nitrate-nitrogen Loss (lb-n/ac) Nitrate-N Loss

39 Corn Yield 200 Corn Yield (bu/acre)

40 N Output with Grain N Output with Corn (lb/acre)

41 N Surplus N Fert. Input - N Grain Output (lb/acre)

42 N Loss versus Surplus 100 Nitrate-N Loss (lb/acre) N Surplus (N Fert. - N Corn Output) (lb/acre)

43 N Concentration versus Surplus 25 Nitrate-N Concentration (lb/acre) N Surplus (N Fert. - N Corn Output) (lb/acre)

44 N Rate versus Load 100 Nitrate-N Loss (lb/acre) N Application Rate (lb/acre)

45 N-Rate versus Concentration 30 Nitrate-N Concentration (mg/l) N Application Rate (lb/acre)

46 N Surplus versus Load 100 Nitrate-N Loss (lb/acre) N Surplus (lb/acre)

47 N Surplus versus Concentration 30 Nitrate-N Concentration (mg/l) N Surplus (lb/acre)

48 Other Practices being Studied at ISU

49 Replicated subsurface drainage plots to evaluate performance of various in-field management practices NWRF Drainage Gilmore City DRF NERF Drainage COBS SERF Drainage

50 Drainage Water Management

51 Impacts of DWM

52 Nitrate Removal Wetland

53 Hydrologic and nutrient loading rates are major drivers of wetland performance. Wetlands occupying only 1% of landscape can reduce long term average nitrate loads about 52%. From: W.G. Crumpton

54 Drainage Area Wetland

55 SERF Wetland Performance

56 SERF Wetland Performance 18 Nitrate-N Concentration (ppm) Inflow Outflow

57 Saturated buffers

58 Subsurface Drainage Bioreactor From Christianson and Helmers, 2011 Illustration by John Petersen (

59 Example Bioreactor 2D Performance Graph 2 30 Nitrate-N Concentration (mg/l) Inflow Outflow Department of Agricultural and Biosystems Engineering

60 Drainage water recycling

61 Department of Agricultural and Biosystems Engineering Discussion Website:

62 Coordinated Site Network for Studying the Impacts of 4R Nutrient Management on Crop Production and Nutrient Loss Dr. Matt Helmers, Professor Iowa State University Dr. Sylvie Brouder, Professor Purdue University Dr. Laura Christianson, Assistant Professor University of Illinois Dr. Cameron Pittelkow, Assistant Professor, University of Illinois Dr. Kelly Nelson, Professor University of Missouri Dr. Dan Jaynes, Soil Scientist USDA-ARS National Laboratory for Ag. and the Environment Dr. John Kovar, Soil Scientist USDA-ARS National Laboratory for Ag. and the Environment Lowell Gentry, Research Scientist University of Illinois Dr. Craig Drury, Research Scientist Agriculture and Agri-Food Canada Dr. Fabian Fernandez, Assistant Professor University of Minnesota Dr. Alison Eagle, Scientist, Sustainable Agriculture, Ecosystems Program, EDF Dr. Jeffrey Volenec, Professor Purdue University Dr. Cliff Snyder, Nitrogen Program Director for the International Plant Nutrition Institute (IPNI)

63 Justification Eagle et al. (2015) noted that only one study reported simultaneous nitrous oxide (N 2 O) emissions and NO 3 leaching losses, along with crop yield information. (4R Research Funded Project) In addition, we are aware of no studies explicitly aimed at understanding the interactions between 4R management strategies, soil health, drainage water quality, and nitrous oxide emissions

64 Objectives Our objective is to: Quantify the impact of 4R Nutrient Stewardship on crop yield, soil health, nutrient use efficiencies, nutrient losses with leaching, and gaseous nitrogen losses across a network of coordinated studies in the major corn producing area of North America. Figure 1. Location of study sites. Project Funded by the FFAR (Foundation for Food and Agriculture Research) and The 4R Research Fund