71st SWCS International Annual Conference July 24-27, 2016 Louisville, KY

1. OHIO STATE UNIVERSITY EXTENSION
Improving Soil Health with
Cover Crops and Cropping
Diversity
Alan Sundermeier
Sundermeier.5@osu.edu
419-354-9050

2.  Cropping diversity especially agronomic crop rotation
with cover crops acts as a biological primer to improve
functional stability of no‐till system.
 The long‐term effects (2004 to 2014) of corn, corn‐
soybean and corn‐soybean‐wheat rotation with or
without cover crops on soil health and crop productivity
under continuous no‐till were evaluated.

3. Cover crop and tillage experiment
OSU South Centers at Piketon (2004 – 2015….)
No‐till NT‐C
No‐till NT‐CSW
No‐till NT‐CSWcc
Conv.‐till CT‐C
CowpeaRyeCorn Soy Wheat
No‐till NT‐CS

4. Cowpea planted after
wheat harvest in July

5. Cowpea dies in winter October 3rd week
November 2nd week
Late April

6. Cereal rye planted
after corn in late
October

7. Materials and Methods
Bi‐annual composite soil samples collected at 0 to 45 cm
depth with 15 cm interval from geo‐referenced sites of
each replicated plot were analyzed for‐
(1) Biological health indicators: microbial biomass, basal
respiration, metabolic quotients, enzyme activity,
nematodes and earthworms.
(2) Chemical health indicators: total organic C and N,
active C and N, particulate organic C and N, soil
balancing, and greenhouse gas emissions
(3) Physical health indicators: bulk density, aggregate
size distribution, aggregate stability, available water
capacity, infiltration and hydraulic conductivity.

8. Cover crops biomass production and nutrient content
were analyzed to calculate for nutrient contribution
(e.g. N) and recycling (e.g. P).
Corn, soybean and wheat yield data were collected
and normalized as relative crop yield.
Protein content and nutrient density of grain were
analyzed.
Soil and crop data were normalized to calculate soil
quality based on both inductive and deductive
approaches.

9. Results

10. Cropping diversity
CT-C NT-C
NT-CS
NTCSW
NT-CSWcc
Activemicrobialbiomass
(mg/kg)
0
50
100
150
200

11. Cropping diversity
CT-C NT-C
NT-CS
NT-CSW
NT-CSWcc
Earthwormbiomass
(kg/ha)
0
100
200
300
400
500
600
Fresh wt.
Oven-dried wt.

12. Cropping diversity
CT-C NT-C
NT-CS
NT-CSW
NT-CSWcc
Basalrespiration
(mgCO2/kg/d)
0
10
20
30

13. Cropping diversity
CT-C NT-C
NT-CS
NTCSW
NT-CSWcc
qCO2
(mgCO2/mgSMB/d)
0.00
0.05
0.10
0.15
0.20
0.25

14. Cropping diversity
CT-C NT-C
NT-CS
NT-CSW
NT-CSWcc
Carbonmanagementindex
(CMI)
0
1
2
3
4

15. CT-C NT-C
NT-CS
NT-CSW
NT-CSWcc
Nitrogenmanagementindex
(NMI)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Cropping diversity

16. Cropping diversity
CT-C NT-C
NT-CS
NT-CSW
NT-CSWcc
MacroaggegateStability
(%)
0
20
40
60
80
100

17. Cropping diversity
CT-C NT-C NT-CS NT-CSW NT-CSWcc
Meanweightdiameter(mm)
0.0
0.2
0.4
0.6
0.8
1.0

18. CT‐CS
NT‐CSWcc

19. OSU Soil health
field test kit

20. Cropping diversity
CT-C NT-C
NT-CS
NT-CSW
NT-CSWcc
Relativecropyield
(%)
0
20
40
60
80
100
Tillage
Wheat
Cover crop

21. Cropping diversity
CT-C NT-C
NT-CS
NT-CSW
NT-CSWcc
Soilquality
(%)
0
20
40
60
80
100
Tillage
Wheat
Cover crop
2004 2014

22. Soil quality (%)
0 20 40 60 80 100
Relativecropyield(%)
0
20
40
60
80
100
Poor
quality
Low
quality
Medium
quality
High
quality
CT‐C
NT‐CS
NT‐C
NT‐CSW
NT‐CSWcc

23. Conclusions:
 Cropping diversity had significant impacts on soil health
indicators and crop yield. The impact of cropping diversity
was more pronounced with cover crops under no‐till.
 Biological indicators were more sensitive than chemical
and physical indicators.
 Switching to no‐till crop rotation, it is essential to use
cover crops to improve soil health for higher crop yield.
 Improvements in crop yields lag behind improvements
in soil health.

24. Acknowledge Credit to:
• Dr. Rafiq Islam
• Islam.27@osu.edu
• 740‐289‐2071
• Ohio State University , South Centers

25. Healthy Food
Healthy People
Thanks