Crop Sequence Considerations When Growing Canola

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1 Crop Sequence Considerations When Growing Canola Stewart Brandt Research Scientist Anastasia Kubinec Oilseeds Specialist

2 Crop Sequence Outline How crops affect those that follow Moisture, weed, disease, fertility Yield responses in varying sequences What research trials tell us What crop insurance data tells us Growing Canola after forages Timing and method of termination Decision making dependent on many factors Intensifying Canola Rotations 2

3 Moisture Effects Maturity differences As crops mature they stop using water Earlier maturity can increase storage for subsequent crops Differences in crop water use Rooting depth decreases in the order perennials>biennials>winter cereals>spring cereals and oilseeds>pulses Snow trapping Taller stubble crops [cereals, canola, mustard] trap more snow more effectively than shorter stubble crops [pea, lentil, flax] 3 Results depend on how much snow and on infiltration

4 Weed Control Considerations Target annual broadleaf weeds in cereal crops costs are lower e.g. excellent control in cleavers - $8-14/ac in wheat, $8-24/ac in canola (not LL, only good) can reduce losses in current year, control costs in next broadleaf crop Target grassy weeds in broadleaf crops costs may be lower permit herbicide rotation to avoid weed resistance Other wild oat options than group 1 & 2 herbicides reduce losses, control costs in next cereal crop 4

5 Disease Considerations Disease must be present Crop must be susceptible Climate must be favorable Changing crop types breaks cycle of disease build-up Less disease present for next host crop Make sure you re controlling volunteers. 5

6 Previous Crop Stubble Wheat Canola Pea Alfalfa Canola None RR:L2, DO:L1, SD:H4, BG:H3 RR:L1, DO:L1, SD:M3, RR:L2, DO:L1, SD:L3 Key: RR=root rot, DO=damping off, SD=sclerotinia, BG=blackleg L=low risk, M=medium risk, H=high risk After canola and field pea need to watch out for sclerotinia as medium to high risk for 3 years Sclerotinia also identified in risk after alfalfa Blackleg is the concern on canola-canola rotation Canola on Wheat = NO Disease Concern Source: Adapted Manitoba Crop Rotation Chart from Manitoba Agriculture,

7 Nutrient Use by Crops Nitrogen-fixing crops Fix nitrogen from the air, may extract less N from soil Provide more N to subsequent crops from decomposing residues Nutrient cycling from residues Dependent on crop type, quantity and quality Mycorrhizal vs non mycorrhizal crops Form loose associations with fungi in soil Increase effective size of roots, improves uptake of nutrients like P Canola is non-mycorrhizal and can affect mycorrhizal loving crops like flax 7

8 Yield responses in varying sequences 8

9 Crops Yield More When Grown on Stubble of Another Crop Type : Research Results Yield as % of yield when grown on their own stubble Stubble Type Cereal Oilseed Pulse Cereal Oilseed Pulse Source: Adapted from rotation and sequence studies at Melfort, Aylsham, Scott 9 and Swift Current

10 Crops Yield More When Grown on Stubble of Another Crop Type : Manitoba Crop Insurance Yield as % of yield when grown on their own stubble Stubble Type Cereal Oilseed Pulse Cereal * Oilseed * Pulse * * no data for pulse on pulse stubble so values are relative to overall average Source: Manitoba Agricultural Services Corporation 10

11 Canola Yield on Varying Stubble Types Stubble Type Canola Winter wheat Spring wheat Barley Oat Flax Pea Soybean Yield (% overall) Average yield 83(88) 94(na) 103(100) 100(101) 95(105) 98(104) 101(113) 84(na) Yield (% canola) On canola stubble 100(100) 113(na) 124(114) 120(115) 114(117) 118(118) 122(128) 101(na) Values are averages for , brackets are averages for Source: Manitoba Agricultural Services Corporation 11

12 Crop Yield on Canola Stubble Crop Winter wheat Spring wheat Barley Oat Flax Pea Soybean Yield (% overall) Average yield 104(na) 103(106) 105(105) 104(108) 90(92) 93(89) 99(na) % Yield Gain on canola stubble vs. own stubble +37 (na) +14 (+18) +19 (+19) +22 (+27) na na na Values are averages for , brackets are averages for Source: Manitoba Agricultural Services Corporation 12

13 Seeding Canola after Forages? 13

14 Considerations For Seeding Canola after Forages #1 Is the forage is fully controlled #2 Consider seedbed conditions #3 Moisture conditions #4 Method of termination #5 Type of forage 14

15 Forage Re-growth. Can reduce yield by 50% Can inflate herbicide costs, cost yield Can interfere with harvest Consider delaying canola for a year RR may be better than LL and others likely don t fit 15

Volunteer Control Can Affect Canola Selection Think of volunteer perennial plants like dandelions tough to kill, are all herbicides going to work?

16 Volunteer Control Can Affect Canola Selection Think of volunteer perennial plants like dandelions tough to kill, are all herbicides going to work? Use your Guide to Crop Protection charts Getting out of Alfalfa with Herbicides (MAFRI) 16

17 Managing Seeding Conditions Assess the seedbed Termination including tillage: Cloddy soil small seeded canola could have issues emerging, need good moisture to mellow up soil bed No-till, chemical termination: Caution around seeding into soil vs. thatch layer May need to increase seeding rates to compensate for questionable seed bed 17

18 Moisture Conditions & Recharge Earlier termination increases moisture Better forage control reduces moisture use No till reduces moisture loss Recharge quicker in parkland vs. dry prairie Clays more moisture > loams > sandy soils 18

19 Termination method Tillage hastens N release from forage residues Most N released in second year, possibly third with tillage Chemical followed by tillage sometimes best compromise 2 strategies for control better than 1 Tillage hastens decomposition Chemicals only in dry climates 19

20 Type of forage Pure alfalfa stands have more N and release it more quickly Mixed, weedy or grass only will likely require more fertilizer N Important to soil test and provide field history 20

21 When to Seed Canola? Canola may fit as first crop if; Forage was primarily alfalfa Forage was terminated early with some tillage Forage is completely controlled [RR vs LL?] May want to consider wheat or flax first After perennial grasses If terminated late, no tillage Lower nutrient requirements of flax; protein response of wheat to N late in season Larger seeded wheat if seedbed has poor structure 21

22 Thinking of Intensifying Intensifying Canola Rotations? 22

23 Influence of rotation length on blackleg [14 site-years at Scott and Melfort, ] Invigor Westar Blackleg severity (0-5) Cont C C-W C-W-P C-W-P-W Rotation 23

24 Influence of rotation on canola yield; [Scott and Melfort , dry conditions] 50 InVigor Westar Yield (bu/ac) Cont C-W C-W-P C-W-P-W Rotation 24

25 50 Influence of rotation on canola yield [Scott and Melfort , normal moisture] InVigor Westar 40 Yield (bu/ac) Cont C-W C-W-P C-W-P-W Rotation 25

26 Preliminary Economics : Intesifying Canola Rotations Seed: $2.20/lb $7.00/lb Herbicide Cost = $27.25/ac (SK Ag) Actual costs were less for InVigor, more for Westar Fertilizer costs (SK Ag) Fertilizer costs less than speculated Grain prices averages [SAF] Canola at $312/t [$7.10/bu] Pea at $160/t [$4.35/bu] Wheat at $144/t [$3.90/bu] 26

27 Economics COSTS Rotation Variable costs [$/ac] Invigor Westar Continuous canola Canola-wheat Canola-wheat-pea Canola-wheat-pea-wheat

28 Net Returns [$/ac] Averages for Scott and Melfort Rotation (dry) (norm) InVigor Westar InVigor Westar Continuous canola Canola-wheat Canola-wheat-pea Canola-wheat-pea-wheat

29 Intensive Canola Rotations Growing canola more frequently increases blackleg, even with resistant varieties Will intensive rotations increase risk that blackleg resistance will break down? Weed control is not a major constraint with HT canola Need better understanding of sclerotinia implications?? Agriculture and Agri-Food Canada 29

30 CONCLUSION A well planned and managed rotations puts all available crop management tools into use 30

31 Thank You!! Stewart Brandt, M.Sc. Research Scientist, Soil and Crop Management AAFC Scott Research Farm Telephone: (22) Anastasia Kubinec, M.Sc. Oilseeds Specialist Crops Knowledge Centre Manitoba Agriculture, Food and Rural Initiatives Telephone: Agriculture and Agri-Food Canada

Designing the Cropping System with the Right Water Intensity

Designing the Cropping System with the Right Water Intensity Brian McConkey*, Perry Miller**, Sangu Angadi*, and Y. T. Gan * *Agriculture and Agri-Food Canada, Swift Current, SK ** Dept. Land Resources