improving soil health with cover crops sundermeier
TRANSCRIPT
OHIO STATE UNIVERSITY EXTENSION
Improving Soil Health with Cover Crops and Cropping
DiversityAlan Sundermeier
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.
Cover crop and tillage experimentOSU 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
Cowpea planted after wheat harvest in July
Cowpea dies in winter October 3rd week
November 2nd week
Late April
Cereal rye planted after corn in late October
Materials and MethodsBi‐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.
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.
Results
Cropping diversity
CT-C NT-C NT-CSNTCSW
NT-CSWcc
Activ
e m
icro
bial
bio
mas
s (m
g/kg
)
0
50
100
150
200
Cropping diversity
CT-C NT-C NT-CSNT-CSW
NT-CSWcc
Eart
hwor
m b
iom
ass
(kg/
ha)
0
100
200
300
400
500
600
Fresh wt. Oven-dried wt.
Cropping diversity
CT-C NT-C NT-CSNT-CSW
NT-CSWcc
Bas
al re
spira
tion
(mg
CO
2/kg
/d)
0
10
20
30
Cropping diversity
CT-C NT-C NT-CSNTCSW
NT-CSWcc
qCO
2 (m
g C
O2/
mg
SMB
/d)
0.00
0.05
0.10
0.15
0.20
0.25
Cropping diversity
CT-C NT-C NT-CSNT-CSW
NT-CSWcc
Car
bon
man
agem
ent i
ndex
(CM
I)
0
1
2
3
4
CT-C NT-C NT-CSNT-CSW
NT-CSWcc
Nitr
ogen
man
agem
ent i
ndex
(NM
I)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Cropping diversity
Cropping diversity
CT-C NT-C NT-CSNT-CSW
NT-CSWcc
Mac
roag
gega
te S
tabi
lity
(%)
0
20
40
60
80
100
Cropping diversityCT-C NT-C NT-CS NT-CSW NT-CSWcc
Mea
n w
eigh
t dia
met
er (m
m)
0.0
0.2
0.4
0.6
0.8
1.0
CT‐CS
NT‐CSWcc
OSU Soil health field test kit
Cropping diversity
CT-C NT-C NT-CSNT-CSW
NT-CSWcc
Rel
ativ
e cr
op y
ield
(%)
0
20
40
60
80
100
Tillage
Wheat
Cover crop
Cropping diversity
CT-C NT-C NT-CSNT-CSW
NT-CSWcc
Soil
qual
ity(%
)
0
20
40
60
80
100
Tillage
Wheat
Cover crop
2004 2014
Soil quality (%)0 20 40 60 80 100
Rel
ativ
e cr
op y
ield
(%)
0
20
40
60
80
100
Poorquality
Lowquality
Mediumquality
Highquality
CT‐C
NT‐CS
NT‐CNT‐CSW
NT‐CSWcc
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.
Acknowledge Credit to:
• Dr. Rafiq Islam• [email protected]• 740‐289‐2071• Ohio State University , South Centers
Healthy Food
Healthy People
Thanks