Integrating Cover Crops into Specialty
Crops Production
Cary L. Rivard, Ph.D.
Dept of Horticulture
Kansas State University
Overview
Cover Crops for Vegetable Production
• Benefits of cover crops
• Challenges
• Tools
• Cover Crops for KS
• High Tunnels
• No-till Research
Cover Crops
• Also known a “green manures”, cover crops are extremely important for soil health – Organic matter – Soil microbial health
• Suppress Weeds
• Add / Recover nitrogen – Highly-leachable N03
– Legume cover crops fix N
• Can be used as mulch – No-till or strip-tillage
• Can reduce excess nutrients (P)
• Reduce soil erosion
Cover Crops Have Numerous Benefits
Nitrogen Recovery / Deposition
Benefits of Cover Crops
• NO3 Recovery
• Legume cover crops
• Calculated lbs/A N
– Legumes
• 3.5-4% (young tissue)
• 3-3.5% (flowering)
– Grasses
• 2-3% (young tissue)
• 1.5-2.5% (flowering)
Lbs biomass
Estimated % N
50% Availability
Total Nitrogen
x
x =
Biomass (lbs/acre) C:N
Available N
Rye Vetch (lbs/acre)
High Tunnel 3749.4 329.4 9.8 83.2
Field 721.8 1589.1 8.5 54.2
Benefits of Cover Crops
Reduced Weed Seed Bank
Benefits of Cover Crops
• Weed seed germination
– Light
– Soil disturbance
• Cover crops
– Competition
• Life cycle interruption
– Reduced seed bank
Grow Your Own Mulch
Benefits of Cover Crops
• Cover crop residues serve as mulch – Weed management
– Soil moisture
– Crop health and quality
• Source of soil carbon
• Source of nitrogen
• “Low Risk”
Challenges exist with cover crops
Challenges of Cover Crops
• Managing cover crop biomass
• Equipment
• Disease and pest pressure
• Production logistics
– Have a CC plan!
Southern Blight on Tomato
Planning for Cover Crops
Winter CC
Winter CC Cash (Vegetable) Crops
Fall Cash Crops Fall Cash Crops Summer Cover Crops
Fall CC Winter CC Cash (short) Crops
Winter CC
A few scenarios for planning your rotation
• Warm-Season Vegetables
• Cool-Season Vegetables
• Fall Cover Crops
Tools Required for Cover Crops
• Overhead Irrigation – Aluminum solid set – “Big Gun” sprinkler
• Managing cover crops – Scythe – Pole trimmer (small) – Flail mower – Roller crimper (large) – Herbicides ??
Getting Started
Annual Grasses - Rye, Wheat, Oats, etc.
• High biomass – Rye is highest – Straw production
• Nitrogen recovery
• Weed competition – Allelopathy (Rye)
• Killing the crop – Early crops
• Plant Sept 1 – Nov 15
Winter Cover Crops
Crop Winter Rye
Annual Legumes
Winter Cover Crops
• Fix Nitrogen
– Inoculant
• Clovers
• Vetch
• Winter peas
• Easier to kill
• Less biomass (straw)
Crimson Clover (Annual)
Annual Grasses – Sorghum, Millet, Spring Oats
• High Biomass – Nitrogen recovery
– Weed competition
– Mulch / OM production
• Short duration – Millet (45 days)
• Can be particularly difficult to kill – Sorghum-Sudan
Summer Cover Crops
Foxtail Millet
Annual Summer Legumes
• Fix Nitrogen – Inoculant
• Soybean
• Forage soybean – Biomass
• Berseem Clover – Pollinators
• Cowpea – Very drought tolerant
Cowpeas
Summer Cover Crops
Cover Crops in Tunnels
Cover Crops are important in high tunnels
• Need to retain soil quality
• Challenges
– Irrigation
– Real Estate
• “Short-window” crops
• Mowing down the crop
• Moveable tunnels
• Benefit to soil:
• Microbial health and structure
• Weed seed bank
• Carbon / organic Matter
• Benefit to crops:
• Better yield and stability
• N fertilizer
• Weed management
• Have a management plan for cover crops
Summary Cover Crops benefit the soil and the farm
No-Till Pumpkin Research Evaluation of cover crops for NT Pumpkins
• C.L. Rivard, M. Kennelly, J. Griffin
• John C. Pair Hort. Center – Richard Ryer
• KCSAAC Grant
• Spring Cover Crops
No-Till NRCS CIG Project NRCS Conservation Innovation Grant Program
• Rivard, C.L., M. Kennelly, J. Griffin, R. Janke, D. Presley, P. Tomlinson, R. Wynia (NRCS), M. Bates (MU)
• Demonstrate no-till systems – Pumpkin, sweet corn, snap bean – Equipment (planter) experience
• 4 replicated trials at KSU/NRCS locations
• 16 demonstration trials at commercial farms (2014-15)
30’
60’
280’
5’
= 1 - Conventional Tillage
= 2 – Winter Rye
= 3 – Winter Rye / Pea
= 4 – Winter Rye / Hairy Vetch
= 5 – Winter Rye / Tillage Radish
= 6 – Rye / Vetch / Radish
= 7 – Spring Oats
= 8 – Spring Oats / Pea
50’ 60’
30’
Not to scale. Each plot will contain three (50’) rows.
Soil Quality Data Collection
9’
A
BC
AB A
36.7
A
D
D
0
10
20
30
40
50
60
70
80
90
100
Conv. Tillage
Winter Rye
Rye / Pea
Rye / Vetch
Rye / Raddish
Rye / Vetch / Raddish
Spring Oats
Oats / Pea
Pe
rce
nt
We
ed
Co
vera
ge (
%)
2013 No-Till Pumpkin Trials
Wichita
Olathe
CD BCD
BC
D
BCD BCD
A
B
0
200
400
600
800
1000
1200
1400
1600
1800
Conv. Tillage
Winter Rye
Rye / Pea
Rye / Vetch
Rye / Raddish
Rye / Vetch / Raddish
Spring Oats
Oats / Pea
Tota
l Est
imat
ed
Fru
it Y
ield
(lb
s/p
lot)
2013 No-Till Pumpkin Trial at JCP Center
D
BCD BCD
CD
BCD
BC
A
AB
0
10
20
30
40
50
60
70
80
90
Conv. Tillage
Winter Rye
Rye / Pea
Rye / Vetch
Rye / Raddish
Rye / Vetch / Raddish
Spring Oats
Oats / Pea
Ave
rage
Fru
it N
um
be
r (#
/plo
t)
2013 No-Till Pumpkin Trial at JCP Center
B
B B
B
B
B
A
B
0
10
20
30
40
50
60
70
80
90
Conv. Tillage
Winter Rye
Rye / Pea
Rye / Vetch
Rye / Raddish
Rye / Vetch / Raddish
Spring Oats
Oats / Pea
Ave
rage
Fru
it W
eig
ht
(lb
s/fr
uit
) 2013 No-Till Pumpkin Trial at JCP Center
• Cover crop selection and cultivation is very important
• The jury is still out on spring cover crops
• Hairy vetch can be hard on planters
• Nitrogen management is a critical component to successful NT systems
Preliminary Conclusions No-Till Pumpkins in Kansas
Top Related