Reconsidering Red Clover. Bill Deen, Dave Hooker, Amelie Gaudin Presented at 8 th Annual MCCC Meeting February 28, 2013 London, Ontario

Transcription

1 Reconsidering Red Clover Bill Deen, Dave Hooker, Amelie Gaudin Presented at 8 th Annual MCCC Meeting February 28, 213 London, Ontario

2 Addition of winter wheat provides niche for cover crop opportunity In a corn/soybean/winter wheat rotation winter wheat rotation often perceived as contributing the least to profitability but perhaps it is equal or more Longterm trials at Elora Research Station and Ridgetown Campus demonstrate that addition of winter wheat provides Increase of yield and yield stability of corn and soybean Reduction of corn N requirement Net return from wheat straw An opportunity for cover crop and associated benefits

3 Elora Research Station : 1625 acres, silt loam soil, 9mm annual rainfall, CHU

4 Long-term rotation trial, 211 Corn Soybean CT NT Alfalfa Barley Wheat Initiated in 198 Rotations CCCC, AAAA, CCAA, CCSS, CCSW, CCSW(rc), CCOB, CCO(rc)B(rc) Conventional tillage and no-till

5 Soybean yield (bu/ac) The Rotation Effect Wheat on Soybean Yields - Elora MP NT SSCC SWCC SW(rc)CC

6 2nd year corn yield Irst year corn yield The Rotation Effect Wheat on Corn Yields - Elora MP NT MP NT

7 Ridgetown Long-Term Tillage-Rotation Established 1995 (by Doug Young) 5 Crop Rotations C-C S-S C-S S-W 4 N treatments in corn and wheat Red clover underseeded in wheat plots

8 C-C C-S C-C C-S C-C C-S C-C C-S Grain Yield (bu/ac) 1. The Rotation Effect Wheat on Corn Yields Ridgetown b 178a 156b 15b 186a a 156b 152b c Note: Mean separation within year (p=.5)

9 S-S C-S S-S C-S S-S C-S S-S C-S Seed Yield (bu/ac) 1. The Rotation Effect Wheat on Soybean Yields Ridgetown a 8 78b 73c 7 69a 6 55b 6a 6b 62b 5 5c 42b 43b 47a 4 3 Rotation Averaged Across Tillage and Corn N treatments at Ridgetown. Est. 1991; letters within year statistically different at p=.5 Source: Hooker et al., 211 (UofG Ridgetown) Note: Mean separation within year (p=.5)

10 (rc) (rc) (rc) (rc) Grain Yield (bu/ac) Corn Yields after Wheat +/- Red Clover, 22 Ridgetown b Ave 181a

11 S-S C-S (rc) S-S C-S (rc) Seed Yield (bu/ac) Soybean Yields with Wheat +/- Red Clover, Ridgetown c 63bc 68a 67ab 56b 59b 66a 68a No-Till Conventional Till Note: Mean separation within tillage system (p=.5)

12 Gaudin et al, 213. Agron.

13 Estimated gross margin of C/S rotation Corn Soy Yield (bu/ac) $/bu Gross Revenue ($/ac) Operating Expenses ($/ac) Gross Margin ($/ac) Operating expenses taken from 212 OMAFRA Crop Budgets - ( Nutrient price taken from October Ridgetown Input Price Survey -

14 Estimated gross margin of C/S/W rotation No red clover Corn Soy Wheat Straw Value Yield (bu/ac) Straw yield 25 lbs $/bu Straw value in winrow.4 $/lb Gross Revenue ($/ac) Nutrient removal.7 $/lb Operating Expenses ($/ac) Net straw value.33 $/lb Gross Margin ($/ac) Adj Gross Margin ($/ac) Red cover N credit GM Diff ($/ac) Ncorn N rate reduction 75 lbs/ac True Gross Margin ($/ac) Nitrogen cost.5 $/lb Red clover success rate. Adjustments Rotation Adjustment (%) 5 8 Straw Revenue ($/ac) 82.5 Red Clover (adj for stand success) (%) Red clover N Adj (adj for stand success) ($/ac). Double crop revenue - oat/pea Bonus Operating expenses taken from 212 OMAFRA Crop Budgets - ( Nutrient price taken from October Ridgetown Input Price Survey -

15 Estimated gross margin of C/S/W rotation Red clover Corn Soy Wheat Straw Value Yield (bu/ac) Straw yield 25 lbs $/bu Straw value in winrow.4 $/lb Gross Revenue ($/ac) Nutrient removal.7 $/lb Operating Expenses ($/ac) Net straw value.33 $/lb Gross Margin ($/ac) Adj Gross Margin ($/ac) Red cover N credit GM Diff ($/ac) Ncorn N rate reduction 75 lbs/ac True Gross Margin ($/ac) Nitrogen cost.5 $/lb Red clover success rate 1. Adjustments Rotation Adjustment (%) 5 8 Straw Revenue ($/ac) 82.5 Red Clover (adj for stand success) (%) 5 5 Red clover N Adj (adj for stand success) ($/ac) 37.5 Operating expenses taken from 212 OMAFRA Crop Budgets - ( Nutrient price taken from October Ridgetown Input Price Survey -

16

17 Overcoming red clover non-uniformity Red clover broadcast timing Drilling versus broadcasting Wheat row spacing Wheat tillage system Wheat N rate Drought tolerance

18 CCSW(rc) no-till CCSW(rc) Conv till

19 kg N ha-1

20 Wheat yield (kg ha-1) Wheat biomass N response curves CNR CWR DHY DSH PJF SNR2 CTB DHG DNR2 INR2 SNR N rates

21 Final red clover biomass (kg ha -1 ) Effect of wheat yield on red clover biomass N 4 N 8 N 12 N R² = Wheat yield (kg ha -1 )

22 Return to N ($ ha -1 ) Wheat yield or red clover biomass (kg ha- 1 ) 7 6 Wheat yield Final red clover biomass MERN = 14 kg N ha Yield at MERN = 591 kg ha -1 RC biomass at MERN = 2119 kg ha N rates

23 Frequency (n=35) Frequency (n=3) Frequency (n=35) Frequency (n=3) Frequency (n=35) Frequency (n=3) Frequency (n=35) Frequency (n=3) Effect of N on RC biomass and stand count distribution 15 N N N N Red clover biomass class (kg ha-1) Red clover stand count class (plt ha-1)

24 Return to Nitrogen ($ ha -1 ) Poor red clover stands variable N application? Key questions: Can ground-based or UAV image systems map variable stands? What is the relationship between image and RC biomass? What is the relationship between RC biomass and nitrogen credit? Does N application equipment match spatial scale of RC variability? Is it economical? Corn following red clover (MERN = 99 kg N/ha) Corn (MERN = 15 kg N/ha) $ to -$25 ha -1 of MERN 5 $ to -$25 ha -1 of MERN Nitrogen Rate (kg-n ha -1 ) Effect of nitrogen rate on returns for corn, average of 19 pair-wise comparisons between $Cdn kg-1, 1 $Cdn t-1)

25