Cover crops: update on the Midwest cover crops council & current issues
Cover Crops and Nitrogen...
Transcript of Cover Crops and Nitrogen...
![Page 1: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/1.jpg)
Cover Crops and Nitrogen Credits
Matt Ruark – UW Madison, Dept. of Soil Science/State Specialist
Jim Stute – Crops & Soils Agent, Rock County
![Page 2: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/2.jpg)
Cover crops and N credits
Review of cover crop systems in WI
Review of recommended N credits
Highlight field research
![Page 3: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/3.jpg)
Types of cover crops used in WICool-season grasses
Green manures
![Page 4: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/4.jpg)
Cool season grasses
Oats, rye
Grow quickly
Provide ground cover in systems that have little crop reside
Potatoes
Corn Silage
“Trap” crop for nitrate
Build soil organic matter
![Page 5: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/5.jpg)
Is there an N credit for cool-season grasses?
No
A reduction in N rates with use of cool- season grasses has not been shown to be effective in midwestern cropping systems
…but are there other advantages?
![Page 6: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/6.jpg)
oat
tritica
le rye oat
tritica
le rye oat
tritica
le rye
0
5
10
15
20
25
30
35
Cor
n Y
ield
Incr
ease
(bu/
a)2001 2002 2003
(No yield increase)
Andraski and Bundy, 2005
Potential yield increase on sandy soils
![Page 7: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/7.jpg)
Legume cover crops (aka Green Manure)
Add free N to soil system
Take longer to establish than rye or oats
Planted after “short-season” crops (wheat, vegetables) for N addition to high N demand crops (corn)
![Page 8: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/8.jpg)
Why does it work?
N
N N
Late Fall Spring
N NNNNNN
N
N
Biological fixation
Mineralization
![Page 9: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/9.jpg)
0
20
40
60
80
100
0 2 4 6 8 10 12 14 16Weeks after planting
Legu
me
N re
leas
e or
C
orn
N u
ptak
e (%
of t
otal
) Legume N Release
Corn N Uptake
Why does it work?
![Page 10: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/10.jpg)
![Page 11: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/11.jpg)
Ruffo and Bollero (2003) Univ. Illinois
![Page 12: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/12.jpg)
Research – Lancaster, WI
1999, 2001
7 cover cropping systems
None
Alfalfa
Hairy Vetch
Red Clover
Medic
Berseem Clover
Crimson Clover
![Page 13: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/13.jpg)
Research – Lancaster, WI
Cover crops planted after winter wheat harvest
Corn planted following spring
1999: 0, 30, 60, 90, 120, 150 lb-N / ac
2001: 0, 25, 55, 80, 100, 135 lb-N / ac
![Page 14: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/14.jpg)
Research – Lancaster, WI
How do we evaluate the N credit?
Build response curves for each system
Determine the economic optimum N rate and yield at optimum N rate (0.1 N/corn price ratio)
R2 = 0.9428100110120
130140150
0 50 100 150
Fertilizer N rate (lb/a)
Cor
n yi
eld
(bu/
a)
![Page 15: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/15.jpg)
1999EONR Yield @ EONR
lb/a bu/aFallow 105 (87 - 123) 204Hairy Vetch 86 (72 - 97) 209Alfalfa 150+ 209Red Cl. 150+ 205Medic 150+ 216Berseem Cl. 84 (67 – 101) 207Crimson Cl. 67 (51 – 83) 204
N credit = 19 to 38 lb/a (average) 26 to 40 lb/a (high end)
14 to 36 lb/a (low end)
![Page 16: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/16.jpg)
2001EONR Yield @ EONR
lb/a bu/aFallow 96 (82 – 109) 140Hairy Vetch 27 (10 – 44) 145Alfalfa 83 (64 – 103) 144Red Cl. 51 (39 – 63) 138Medic 69 (59 – 79) 150Berseem Cl. 84 (73 – 95) 149Crimson Cl. 56 (47 – 65) 149
N credit = 12 to 69 lb/a (average) 6 to 65 lb/a (high end)
18 to 72 lb/a (low end)
![Page 17: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/17.jpg)
Conclusions
There is significant value to using legume cover crops/green manures in a winter wheat-corn rotation
There will be year to year variability with cover crop benefits.
Other legume cover crops are beneficial to Wisconsin cropping systems.
![Page 18: Cover Crops and Nitrogen Creditssoilsextension.webhosting.cals.wisc.edu/wp-content/uploads/sites/6… · Types of cover crops used in WI Cool-season grasses. Green manures. ... but](https://reader034.fdocuments.us/reader034/viewer/2022051910/600008b21d5b953569145935/html5/thumbnails/18.jpg)
Questions?