PROCEEDINGS 2017 Crop Pest Management Short Course & Minnesota Crop Production Retailers Association Trade Show Institute for Ag Professionals http://www.extension.umn.edu/agriculture/ag-professionals/ Do not reproduce or redistribute without the written consent of author(s).
Cover Crops, Nutrients, and Water Quality WHAT WE KNOW AND WHAT NEEDS WORK Melissa Wilson Assistant Professor & Extension Specialist Department of Soil, Water, and Climate University of Minnesota Sabrina Badger Ph.D. Candidate Land and Atmospheric Science University of Minnesota 1
TOPICS What s going on with water quality? How can cover crops help? What do we already know? What are we working on? Future research needs https://inhabitat.com/wp-content/blogs.dir/1/files/2017/06/gulf-of-mexic-algae-bloom-wikimedia-889x635.jpg https://media.npr.org/assets/img/2015/01/31/cereal-20rye-20cover-20on-20corn_wide-21804a5a09c03e522f423e162fd0d0f4459bafb9.jpg?s=1400 http://www.madisonscd.com/images/soil/runoff%20demonstration%20resized.jpg 22
WATER QUALITY ISSUES National issue: Dead zone in the Gulf of Mexico 2014 Size: 5,052 square miles EPA. 2017. Northern Gulf of Mexico Hypoxic Zone. https://www.epa.gov/ms-htf/northern-gulf-mexico-hypoxic-zone 33
WATER QUALITY ISSUES National issue: Dead zone in the Gulf of Mexico 2015 Size: 6,474 square miles EPA. 2017. Northern Gulf of Mexico Hypoxic Zone. https://www.epa.gov/ms-htf/northern-gulf-mexico-hypoxic-zone 44
WATER QUALITY ISSUES National issue: Dead zone in the Gulf of Mexico 2017 Size: 8,776 square miles EPA. 2017. Northern Gulf of Mexico Hypoxic Zone. https://www.epa.gov/ms-htf/northern-gulf-mexico-hypoxic-zone 55
WATER QUALITY ISSUES National issue: Dead zone in the Gulf of Mexico NOAA Environmental Visualization Lab. 2012. The Dead Zone. https://www.nnvl.noaa.gov/default.php 66
WATER QUALITY ISSUES Minnesota contributions to a national issue MPCA. 2014. Nutrient reduction strategy. https://www.pca.state.mn.us/water/nutrient-reduction-strategy 77
WATER QUALITY: SURFACE WATER Minnesota Nutrient Planning Portal. 2017. MNSU. http://mrbdc.mnsu.edu/mnnutrients/ 88
WATER QUALITY: GROUNDWATER Nitrate Concentrations, 2007-2011 Phosphorus Concentrations, 2007-2011 MPCA. 2013. The Condition of Minnesota s Groundwater, 2007-2011. https://www.pca.state.mn.us/sites/default/files/wq-am1-06.pdf 99
WATER QUALITY AND ROW CROPS MN Geospatial Information Office. 2013. http://www.mngeo.state.mn.us/chouse/land_use_recent.html 10
WATER QUALITY AND LIVESTOCK Montgomery. 2015. https://goo.gl/0zfh8b. 11
WATER QUALITY Tile drained field Non-tiled field Sources of nitrate to surface water MPCA. 2014. Nutrient reduction strategy. https://www.pca.state.mn.us/water/nutrient-reduction-strategy 12
WATER QUALITY AND TIME OF YEAR Surface Runoff Soil Loss Phosphorus Loss Nitrogen Loss Nonfrozen 53% Frozen 47% Nonfrozen 92% Nonfrozen 56% Frozen 44% Nonfrozen 38% Frozen 62% Frozen 8% An important period of runoff in the Upper Midwest is during frozen soils and snowmelt Discovery Farms. 2017. http://agwaterexchange.com/2017/10/30/controlling-impact-weather/ 13
WHAT CAN WE DO TO PREVENT NUTRIENT LOSS? Nutrient planning and management 4R Stewardship Use practices to control erosion Keep the land covered with growing crops 14
WHAT DO COVER CROPS DO? Fill the gap between cash crops Hunter M. 2016 Mar. Cover crop cocktails. In: Cover Crops for Soil Health. Dover (DE): NE SARE. 15
WHAT DO COVER CROPS DO? Provide ecosystem services https://www.pca.state.mn.us/sites/default/fil es/wq-am1-06.pdf Image from: SARE Cover Crop Image Library 16
COVER CROPS AND ECOSYSTEM SERVICES Not all cover crop species are created equal From Hunter M. 2016 Mar. Cover crop cocktails. In: Cover Crops for Soil Health. Dover (DE): NE SARE. 17
WHAT DO COVER CROPS DO? Think Risk Management Keep nutrients in the soil and out of our waterways! Scavenge nutrients left from previous crop Retain nutrients from manure Reduce spring nutrient losses from snowmelt and runoff 18
NUTRIENT SCAVENGING Nitrogen uptake values of rye: Fall: Minnesota: 0.01-3.6 lb/a (broadcast in Sep) Spring: Minnesota: 1-20 lb/a (broadcast in Sep) 6-70.5 lb/a (drilled in Sep) New York: 3.6 lb/a (broadcast in Oct) Nebraska: 8-53.5 lb/a (drilled in Oct) 19
NUTRIENT SCAVENGING Practical Farmers of Iowa. 2016. http://www.practicalfarmers.org/blog/2016/07/19/latest-greatest-cover-crop-research-practical-farmers/ 20
WHAT DO COVER CROPS DO? Think Risk Management Keep nutrients in the soil and out of our waterways! Scavenge nutrients left from previous crop Retain nutrients from manure Reduce spring nutrient losses from snowmelt and runoff 21
COVER CROPS AND MANURE Ontario study with manure and various cover crops, 2003-2004 at two sites Cover crops + manure had more biomass and nitrogen uptake than cover crops alone (except red clover) Cover crops took up 0-25% of manure N Did not see a yield boost from cover crops + manure, however Thilakarathna et al. 2015 22
IOWA STUDY: 2005-2006 23 Cambardella et al. 2007. https://www.extension.iastate.edu/pages/communications/epc/fall07/soilcovercrop.html
WHAT DO COVER CROPS DO? Think Risk Management Keep nutrients in the soil and out of our waterways! Scavenge nutrients left from previous crop Retain nutrients from manure Reduce spring nutrient losses from snowmelt and runoff 24
REDUCING RUNOFF LOSSES Runoff: Minnesota study (2010-2011) compared winter rye interseeded at leaf drop into soybeans to fallow ground CC reduced losses by: N 80% in fall 98% in spring P 89% in fall 99% in spring 25
REDUCING RUNOFF LOSSES Wisconsin study from 2016-2017 Cover crops and water quality Total phosphorus reduced in runoff by 42% Particulate phosphorus reduced by 44% 26
REDUCING SUBSURFACE LOSSES Tile-drainage 1998-2002 study in Lamberton, MN Corn-ryeCC-soybean rotation reduced nitrate in tile drainage by 13% compared with no CC in rotation Strock et al. 2004. 1999-2005 study in Ontario, Canada Cover crop added to a corn-soybean rotation reduced nitrate losses by 14-16% compared with no CC in the rotation Drury et al. 2014. 27
REDUCING SUBSURFACE LOSSES Tile-drainage On-farm study from 2006-2009 in Southwestern MN Continuous corn silage Annual manure application Fallow After Corn Silage 5000 Head Dairy Krueger et al. Unpublished data. Winter Rye Seeded After Corn Silage 28
ON-FARM RESEARCH 100 90 80 Nitrate Concentration vs. Date Rye Seeded Rye Killed Corn Silage Corn Silage/Rye NO 3 - -N (mg l -1 ) 70 60 50 40 30 20 10 0 02/27/07 06/07/07 09/15/07 12/24/07 04/02/08 07/11/08 10/19/08 01/27/09 05/07/09 08/15/09 11/23/09 Krueger et al. Unpublished data. Date 29
REDUCING SUBSURFACE LOSSES 100 Nitrate-N Concentration in Leachate Nitrate-N (mg L -1 ) 80 60 40 20 Corn Rye-Corn 0 09/15/07 11/04/07 12/24/07 02/12/08 04/02/08 05/22/08 07/11/08 Leachate data are limited, but a decrease in NO 3 concentration of 27% was observed in one year of data Date Krueger et al. Unpublished data. 30
CURRENT RESEARCH Cover crops and tile drainage Started in 2016 in Waseca, MN Alternate methods for establishing cover crops Interseeding into corn and soybeans Go see Dr. Well s talk if interested! Where does the nitrogen go once cover crops are terminated? 31
NITROGEN AVAILABILITY AND CORN PRODUCTION IN MINNESOTA FOLLOWING COVER CROPS Sabrina Badger Dr. Daniel Kaiser Dr. M. Scott Wells Department of Agronomy and Plant Genetics University of Minnesota Department of Soil, Water, and Climate University of Minnesota Department of Agronomy and Plant Genetics University of Minnesota 32
THE EXPERIMENT Main Plot Medium Red Cover Trifolium pratense Legume Moderately winter hardy Field Pennycress Thalspi avensi Possible oilseed crop Winter hardy Cereal Rye Secale cereale Nitrogen Scavenger Highly winter hardy Cereal Rye + Radish Secale cereale + Raphanus sativus N scavenger and compaction reducer Radish not winter hardy USDA.go v Lamberton Waseca Normania loam and Webster clay loam Canisteo clay loam Sub Plot Rosemount Lindstrom silt loam 0 lb N ha-1 50 lb N ac-1 100 lb N ac-1 150 lb N ac-1 200 lb N ac-1 250 lb N ac-1 33
TIMELINE Summer 2015 Soybeans September 2015 Plant cover crops End April 2016 Terminate cover crops May 2016 Plant corn Apply fertilizer Install PRS probes Begin soil sampling Summer-Fall Periodically take soil samples and swap PRS probes October 2016 Harvest corn Shutterstock 34
OBJECTIVES Leaching-Susceptible Soil Nitrogen Growing Season Nitrogen Availability Corn Yield and Optimum Nitrogen Rates 35
NITROGEN STATUS AT COVER CROP TERMINATION Medium Red Clover Field Pennycress Winter Rye + Radish Winter Rye Within each location, treatments with different letters are significantly different (Fisher s LSD, α=0.05). (Lamberton: P<0.001; Rosemount: P<0.01; Waseca: P<0.01) 36
NITROGEN STATUS AT COVER CROP TERMINATION Medium Red Clover Field Pennycress Winter Rye + Radish Winter Rye Within each location, treatments with different letters are significantly different (Fisher s LSD, α=0.05). (Lamberton: P<0.001; Rosemount: P<0.001; Waseca: P<0.001) 37
NITROGEN STATUS AT COVER CROP TERMINATION Medium Red Clover Field Pennycress Winter Rye + Radish Winter Rye Within each location, treatments with different letters are significantly different (Fisher s LSD, α=0.05). (Lamberton: P<0.01; Rosemount: P<0.001; Waseca: P=0.8) 38
NITROGEN STATUS AT COVER CROP TERMINATION Within each location, treatments with different letters are significantly different (Fisher s LSD, α=0.05). (Lamberton: P<0.001; Rosemount: P<0.001; Waseca: P<0.001) Within each location, treatments with different letters are significantly different (Fisher s LSD, α=0.05). (Lamberton: P<0.001; Rosemount: P<0.01; Waseca: P<0.01) Medium Red Clover Field Pennycress Winter Rye + Radish Winter Rye Within each location, treatments with different letters are significantly different (Fisher s LSD, α=0.05). (Lamberton: P<0.01; Rosemount: P<0.001; Waseca: P=0.8) 39
SPRING SOIL NITROGEN Medium Red Clover None Field Pennycress Winter Rye + Radish Winter Rye Within each location, treatments with different letters are significantly different (Fisher s LSD, α=0.1). (Lamberton: P=0.06; Rosemount: P=0.06; Waseca: P<0.01) 40
NITROGEN AVAILABILITY Within each location, treatments with different letters are significantly different (Fisher s LSD, α=0.05). (Lamberton: P<0.001; Rosemount: P<0.01; Waseca: P<0.01) Medium Red Clover None Field Pennycress Winter Rye + Radish Winter Rye Within each sample time, treatments with different letters are significantly different (Fisher s LSD, α=0.05). (Day*Cover crop P<0.01; Day*N rate P<0.001; Cover crop*n rate P=0.05) 41
NITROGEN AVAILABILITY Medium Red Clover None Field Pennycress Winter Rye + Radish Winter Rye Medium Red Clover None Field Pennycress Winter Rye + Radish Winter Rye Within each sample time, treatments with different letters are significantly different (Fisher s LSD, α=0.05). (Day*Cover crop*n rate P=0.05) Within each sample time, treatments with different letters are significantly different (Fisher s LSD, α=0.05). (Day*Cover crop*n rate P<0.01) Within each sample time, treatments with different letters are significantly different (Fisher s LSD, α=0.05). (Day*Cover crop P<0.01; Day*N rate P<0.001; Cover crop*n rate P=0.05) 42
CONCLUSIONS Cereal (winter) rye significantly reduced spring soil nitrate in all locations. Field pennycress, in development as an oilseed crop, appears to also provide this ecosystem service. Medium red clover was not able to gain significant biomass by termination. Lack of a nitrogen credit from medium red clover is likely due to low cover crop biomass. Lack of a nitrogen credit from winter rye and pennycress is likely due to N losses and/or immobilization, rather than poor synchrony with corn N demand. Note: High variability between years is common in such studies. Also, results may be different after long-term cover crop use. 43
FUTURE RESEARCH What is the adoption rate in MN? Can we use satellite imagery to determine nutrient capture? NASA. 2015. https://earthobservatory.nasa.gov/iotd/view.php?id=90095 44
FUTURE RESEARCH Manure and cover crops What are BMPs for combining the two practices? Can cover crops help reduce issues of early fall applied manure? Seeded: Sep 1 Harvested: Dec 5 45
Any questions? Contact Info: Email: mlw@umn.edu Follow me on : @ManureProf The University of Minnesota is an equal opportunity educator and employer. In accordance with the Americans with Disabilities Act, this PowerPoint is available in alternative formats upon request. Direct requests to 612-624-1222. 46