Benefits of Plant Diversity
Benefits of Plant Diversity Leilani Zimmer-Durand July, 2013 Consultant Meeting
MSU study Fertilizer Conventional Integrated Compost
Rotation CC CSW CC CSW CC CSW
Culman et al., 2013. Short- and Long-Term Labile Soil Carbon and Nitrogen Dynamics Reflect Management and Predict Corn Agronomic Performance. Agronomy Journal, V 105 Issue 2.
• Rotation had the largest effect on soil health
CO2 from the soil
Nitrogen mineralization
Chlorophyll content
• More crops in the rotation = healthier soils
ISU organic study
• • • •
Started in 1998 Conventional C S Organic S W/RC Organic C S O/A Organic C S O/A A
ISU organic study
ISU organic study
ISU organic study
Soil mineral comparison between organic and conventional plots P
K
Mg
Ca
EC
Conv C-S
13.7
218
312
2797
168
Org C-S-O/A
40.6
359
348
3104
213
Org C-S-O/A-A
28.6
338
344
3094
215
Soil Quality comparison Microbial Biomass Carbon 370 350 330 310 290 270 250
Conv
Org C-S-O/A
Org C-S-O/A-A
Soil Quality comparison Potentially Mineralizable N 60
50
40
30
20
10
0
Conv
Org C-S-O/A
Org C-S-O/A-A
Diversity above ground mirrors diversity below ground.
Soil Surface
Concerns about cover cropping • Requires resources – Could compete with crop plant for water or tie up nutrients
• How to kill it completely • What plants fit with what cropping systems • How to fit in a cover crop with a lateseason harvest
Competition? Or Collaboration?
Agroecology pg. 224 (Gliessman, 2000)
Cover crops are a source of plant diversity
Collaboration vs. competition • North Dakota case study: • 2006 Production On Burleigh District Plot with 1.8 inches of rain
Turnip July 31
Oilseed Radish July 31
Cocktail July 31
The power of diversity: Collaboration is more apparent than Competition 4785
Lbs. dry matter/plot
4350
Cocktail Mixture full rate plot
Cocktail Mixture 1/2 rate plot
1914
Cow Pea Plot
1513
Purple Top Radish
1496
Pasja Turnip Plot
1260
Oil Seed Radish
1232
Lupin Plot
5000 4500 4000 3500 3000 2500 2000 1500 1000 500 0
Furrow Article • The Furrow • Summer 2013 Issue
Cover crops conserve soil moisture
• Nebraska: – Increased infiltration – Reduced evaporation
Cover crops conserve soil moisture
• Kansas, spring cover crop – By June 13th: – 14% more moisture in 60 inch soil profile – 30% more moisture in top 8 inches
Cover crops rob soil moisture
• CO and NE USDA study: – Cover crops used 6 inches of soil water – 2x as much as fallow
Cover crops rob soil moisture • Kansas State U: – More moisture in seed zone (1 to 3 inches) – Less moisture in total soil profile – 20 bushel wheat yield loss during drought
SARE farmer survey • 2012 Drought: • Corn yields down 26.3% • Soybean yields down 8.1%
SARE farmer survey
SARE farmer survey
Variety and blends • And no one really sure how variety affects water usage … • or which cover crop/cropping system are ideal mixes.
Cornerstone of Biological Farming • Huge benefits to crop diversity – Biology – Structure – Mineral availability – Pest cycles
MSU study Fertilizer Conventional Integrated Compost
Rotation CC CSW CC CSW CC CSW
Culman et al., 2013. Short- and Long-Term Labile Soil Carbon and Nitrogen Dynamics Reflect Management and Predict Corn Agronomic Performance. Agronomy Journal, V 105 Issue 2.
• Rotation had the largest effect on soil health
CO2 from the soil
Nitrogen mineralization
Chlorophyll content
• More crops in the rotation = healthier soils
ISU organic study
• • • •
Started in 1998 Conventional C S Organic S W/RC Organic C S O/A Organic C S O/A A
ISU organic study
ISU organic study
ISU organic study
Soil mineral comparison between organic and conventional plots P
K
Mg
Ca
EC
Conv C-S
13.7
218
312
2797
168
Org C-S-O/A
40.6
359
348
3104
213
Org C-S-O/A-A
28.6
338
344
3094
215
Soil Quality comparison Microbial Biomass Carbon 370 350 330 310 290 270 250
Conv
Org C-S-O/A
Org C-S-O/A-A
Soil Quality comparison Potentially Mineralizable N 60
50
40
30
20
10
0
Conv
Org C-S-O/A
Org C-S-O/A-A
Diversity above ground mirrors diversity below ground.
Soil Surface
Concerns about cover cropping • Requires resources – Could compete with crop plant for water or tie up nutrients
• How to kill it completely • What plants fit with what cropping systems • How to fit in a cover crop with a lateseason harvest
Competition? Or Collaboration?
Agroecology pg. 224 (Gliessman, 2000)
Cover crops are a source of plant diversity
Collaboration vs. competition • North Dakota case study: • 2006 Production On Burleigh District Plot with 1.8 inches of rain
Turnip July 31
Oilseed Radish July 31
Cocktail July 31
The power of diversity: Collaboration is more apparent than Competition 4785
Lbs. dry matter/plot
4350
Cocktail Mixture full rate plot
Cocktail Mixture 1/2 rate plot
1914
Cow Pea Plot
1513
Purple Top Radish
1496
Pasja Turnip Plot
1260
Oil Seed Radish
1232
Lupin Plot
5000 4500 4000 3500 3000 2500 2000 1500 1000 500 0
Furrow Article • The Furrow • Summer 2013 Issue
Cover crops conserve soil moisture
• Nebraska: – Increased infiltration – Reduced evaporation
Cover crops conserve soil moisture
• Kansas, spring cover crop – By June 13th: – 14% more moisture in 60 inch soil profile – 30% more moisture in top 8 inches
Cover crops rob soil moisture
• CO and NE USDA study: – Cover crops used 6 inches of soil water – 2x as much as fallow
Cover crops rob soil moisture • Kansas State U: – More moisture in seed zone (1 to 3 inches) – Less moisture in total soil profile – 20 bushel wheat yield loss during drought
SARE farmer survey • 2012 Drought: • Corn yields down 26.3% • Soybean yields down 8.1%
SARE farmer survey
SARE farmer survey
Variety and blends • And no one really sure how variety affects water usage … • or which cover crop/cropping system are ideal mixes.
Cornerstone of Biological Farming • Huge benefits to crop diversity – Biology – Structure – Mineral availability – Pest cycles
