The role of agronomics in relation to meeting current and future agricultural and cropping systems challenges

Transcription

1 The role of agronomics in relation to meeting current and future agricultural and cropping systems challenges J.T. O Donovan Agriculture and Agri-Food, Lacombe Research Centre, Lacombe, Alberta

2 On-farm positive changes in crop production in western Canada Conservation tillage Crop rotation ti Seeding date Herbicide timing Crop seed rate Crop fertilization

3 Conservation tillage Ground cover greatly reduces erosion Standing crop stubble facilitates greater snow trapping and reduces evaporation More soil water for crop growth 70% of crops are direct-seeded d d 45% zero-till, 25% reduced till But what about the weeds?

4 Effect of tillage systems on weed seeds in the seed bank in fall Weed seed/m d/ Conventional Minimum Zero Stinkweed Lamb squart Wild buck Green foxt O Donovan and McAndrew 1998

5 Effect of tillage systems on weed seedling emergence in spring Weeds /m Conventional Minimum 30 Zero Stinkweed Lamb squart Wild buck Green foxt

6 Weed surveys ty ) d densi ants/m 2 ) Weed (pla Thomas et al. 2005

7 Microbial biomass Greater microbial biomass under ZT than under CT. Highest biomass in wheat following red clover and lowest biomass in wheat following summer fallow Lupwayi et al. 1998

8 No-till increases soil microbial diversity 5 Conventional tillage No tillage 4 rsity index (H') Dive Fallow Wheat Clover GM Pea Lupwayi et al Previous crop

9 CO 2 evolution (Microbial Activity) Lower CO 2 evolution under ZT than under CT. Lowest CO 2 evolution in wheat following peas under ZT.

10 Where do we go from here with conservation tillage research? Beneficial arthropods as affected by tillage Phosphorus use efficiency in conservation tillage systems Micronutrient application in conservation tillage systems e.g. copper Nitrogen mineralization in well managed conservation tillage systems???

11 Impact of removing inputs on yield [average over 4 years (2005 to 2008) at 5 locations] Crop yield (kg/ha) % N - 50% N - 100% N Canola Barley

12 N fertility Are we overestimating fertilizer N requirements on well managed fields Credit No Till, continuous cropping, pulse rotations and long term fertilizer use? Accurate estimates of N supplied by soil becomes more important Do we need a method to predict N supply from soil 11

13 On-farm positive changes in crop production in western Canada Conservation tillage Crop rotation ti Seeding date Herbicide timing Crop seed rate Crop fertilization

14 Crop Rotation Rotating cereals with oilseeds and pulses Diverse rotations ti are essential to effective long-term crop and pest management Facilitates herbicide rotation Much less monoculture cropping in western Canada than there used to be introduction of HR canola, greater awareness of disease issues

15 Percentage leaf area diseased (flag leaf 2) after 5 yr of continuous barley and barley in rotation with canola and field pea ased LSD (0.05) = 2.2 % leaf ar rea dise Vivar AC Lacombe 0.0 Continuous Rotation Turkington et al.

16 Pulses in rotation Better soil and crop health Reduced d dependence d on inorganic i N fertilizers More sustainable st weed management m

17 N fixation ability of pulses 2007 Trt 1 Pea, Camry 2 Pea, Pea, Camry, stubble only 4 Pea, 4010, stubble only 5 Faba bean, seed 6 Faba bean, GM 7 Chickling vetch (AC Greenfix) 8 Barley 16

18 N Fixed (kg/ha) by various legumes 250 a b b bc c bc 0 Camry Pea 4010 Pea Camry, No Res. 4010, No Res. Faba, Seed Faba, GM Vetch, GM Faba > 4010 pea & Camry pea > GMs Luwayi et al. (unpublished)

19 Green manure Widely used by organic farmers Sweetclover, red clover Limited use by conventional nti n farmers

20 Weed suppression with sweetclover residue Sweetclover Weed growth without t residue sweetclover J. Moyer, AAFC, Lethbridge

21 Pulses in rotation the future The knowledge of rotational effects of pulse crops in the Northern Great Plains remains imprecise and inadequate - Miller et al Canola following a pulse hybrids are avid users of nitrogen Are there disease issues? Prairie canola agreement

22 On-farm positive changes in crop production in western Canada Conservation tillage Crop rotation ti Seeding date Herbicide timing Crop seed rate Crop fertilization

23 Never seed canola before the middle of May Early spring Late spring Clayton et al

24 Never seed canola before the middle of May! Yield (bu 40 u/acre) LSD (0.05) = Late April Mid May Time of Seeding Exceed InVigor 2153 Clayton et al. 2005

25 Economics of canola seeding time Hybrid Open Pollinated $800 $600 $400 $200 $0 Early Spring Late Spring Returns from hybrids are higher than open pollinated Early spring seeding has highest h returns Upadhyay et al. 2005

26 On-farm positive changes in crop production in western Canada Conservation tillage Crop rotation Seeding date Herbicide timing Crop seed rate Crop fertilization

27 Time of Weed Removal - Canola Yield (kg/ha) bu/ac bu/ac bu/ac 1 to 2 3 to 5 6 to 7 Canola Leaf Stage Means of 10 western Canada locations CCC Agronomists - large-scale plots (9 x 122 m) in grower fields Harker et al Weed Technol. 22:

28 Waiting to Spray $ lost / half section 6-7 Leaf $650/t Leaf $250/t $Lost

29 On-farm positive changes in crop production in western Canada Conservation tillage Crop rotation ti Seeding date Herbicide timing Crop seed rate Crop fertilization

30 Barley seed rate effects on wild oats without herbicide Normal seed rate High seed rate

31 Do western Canadian growers reduce in-crop herbicide rates? Province Herbicide rate < Recom. > Recom. None Alberta 38% 13% 8% Saskatchewan 26% 5% 12% Manitoba 32% 9% 1% Average 32% 9% 7% Leeson et al. 2007; Thomas et al. 2007

32 Importance of crop competition in enhancing herbicide performance Wild oat dw (g/m 2 ) Herbicide In crop No crop Difenz Diclofop Flamprop From Sharma and Vanden Born, 1983

33 Effect of 0.75x herbicide rates on wild oat control in wheat seeded at low and high seeding rates yr 3 Normal seed rate O Donovan et al Double normal seed rate

34 Crop seeding rate effects on herbicide efficacy in semi-dwarf barley (barley/canola) 25% herbicide rate normal seed rate 25% herbicide rate - double seed rate O Donovan et al. 2001

35 Competitive barley varieties Semi-dwarf - poor Tall -strong competitor O Donovan et al competitor

36 Seeding rate Improved crop competition and herbicide performance Earlier, more uniform maturity reduced green seed content in canola more uniform kernel size in cereals (better malt and feed quality) Less risk of frost damage Farmers have increased seed rates by 30-50% in the last 6 years Less overall herbicide application

37 Continuous barley vs rotation; tall vs short barley; 200 vs 400 seeds/m 2 ; 25, 50 and 100% herbicide rate Harker et al. 2009

38 Wild Oat biomass (maturity) in % herbicide rate for 5 years kg/ha to 400 = 3X reduction Short to Tall = 2X reduction 4000 Both factors = 8X reduction All factors = 70X reduction Continuous Rotation 65 Short 200 Tall 200 Short 400 Tall 400 LSD (0.05) = 614

39 25% herbicide rate every year for 5 years August 23, % herbicide id rate every year for 5 years - Short seeds - B-B-B-B-B - 25% Rate Tall 400 seeds B-C-B-P-B 25% Rate

40 Surface broadcast nitrogen 4 years Wild mustard in wheat 50% reduction in surface broadcast fertilizer in favor of subsurface banded in the last 6 years. Adoption of conservation tillage has facilitated t this Blackshaw et al Subsurface banded nitrogen - 4 years

41 Weed resistance to glyphosate when sound agronomy succumbs to the magic bullet Lolium rigidum - Rigid Ryegrass Australia, USA, South Africa Eleusine indica Goosegrass Malaysia Conyza canadensis Horseweed USA many States) Lolium multiflorum - Italian Ryegrass Chile, Brazil, USA Plantago lanceolata - Buckhorn Plantain South Africa Conyza bonariensis - Hairy Fleabane South Africa, Spain, Brazil, USA Ambrosia artemisiifolia - Common Ragweed USA (several states) 2004 Ambrosia trifida Giant ragweed Indiana, Kansas Amaranthus palmeri - Palmer Amaranth USA (Georgia) 2005 Sorghum halepense - Johnsongrass Argentina 2005 Amaranthus rudis Common waterhemp Illinois, Kansas 2006 Euphorbia heterophylla Wild poinsetta Brazil 2007 Echinochloa colona Junglerice Australia No reports of glyphosate resistance in Canada Yet!! Source: Heap

42 Palmer amaranth (Amaranthus palmeri) Glyphosate resistant palmer amaranth Georgia 2005 (1 site) in RR cotton in Georgia Documented in RR cotton Other biotypes have developed resistance to herbicides in Groups B, C1 and K1 Has this affected the land value? S. Culpepper, University of Georgia

43 Objectives To determine the relative importance of various agronomic factors in relation to barley seed uniformity and yield and malt homogeneity and quality The project is the first of its kind in North America to link agronomic practices directly to quality as determined by the micro-malt malt assessment process (Mike Edney, Canadian Grain Commission)

44 Agronomic factors investigated Variety Seeding date Seeding rate Nitrogen rate Stubble type Fungicide application Three research trials (zero tillage) at 8 locations

45 Relationship between seeding rate and plump seed in 2007 % plump seed sometimes decreased with increasing seed rate ump (%) Pl Fort Vermilion 100 y= x , r 2 = Plu ump (%) Scott 90 y= x, 04 r 2 = Barley seeds/m 2 Barley seeds/m 2

46 Relationship between seeding rate and days to maturity Days to barley seed maturity always decreased with increasing seeding rate 96 All Locations y2 y= x, 012 r 2 = maturity ays) Seed m (da Barley seeds/m 2

47 Relationship between seeding rate and malt protein and beta-glucan Malt protein and beta-glucan mostly decreased with increasing seeding rate protein (%) Malt y = x, r 2 = 0.87 Beta a-glucan y = x x 2, r 2 = Barley seeds/m Barley seeds/m 2

48 Relationship between seeding rate and malt extract Malt extract increased with increasing seeding rate y = x, r 2 = 0.92 Malt ext tract (%) Barley seeds/m 2

49 Relationship between seeding rate on friability and homogeneity Friability and homogeneity increased with increasing seed rate y = x, r 2 = 0.89 y = x, r 2 = 0.80 Friab bility (%) eneity (% %) Homog Barley seeds/m 2 Barley seeds/m 2

50 Why? More uniform kernel size and better modification at the higher seeding rates Edney et al. (unpublished)

51 Relationship between nitrogen rate and yield Barley yield mostly increased with increasing seeding rate eld (kg/ha a) Barley yi Lacombe 5500 y= x-0.11x 26 2, r 2 = Nitrogen rate (kg/ha) Barley yi ield (kg/ha a) Indian Head 5500 y= x-0.11x 11 2, r 2 = Nitrogen rate (kg/ha)

52 Relationship between nitrogen rate and malt protein and beta-glucan Malt protein and beta glucan increased with increasing nitrogen rate Malt prot tein (%) All locations y = x, r 2 = Nitrogen rate (kg/ha)( g Beta-gl ucan All Locations y = x, r 2 = Nitrogen rate (kg/ha)

53 Relationship between nitrogen rate and malt extract and beta-glucan levels Malt extract decreased with increasing nitrogen rate All Locations y = x, r 2 = 0.99 Malt extra act (%) Nitrogen rate (kg/ha)

54 Interaction between nitrogen rate and barley variety on % friability and homogeneity Friability and homogeneity decreased with increasing nitrogen rate but the negative effect was more pronounced with AC Metcalfe Friabil lity (%) All Locations AC Metcalfe: y = x, r 2 = CDC Copeland: y = x, r 2 = Nitrogen rate (kg/ha) Homoge neity (%) All Locations AC Metcalfe: y = x, r 2 = 0.98 CDC Copeland: y = x, 04x r 2 = Nitrogen rate (kg/ha)

55 Future malting barley agronomic research Can we mitigate the negative impact of nitrogen on malt barley quality without seriously impairing yield? How do other varieties respond to nitrogen in terms of malt quality? What about varietal mixtures in terms of responses to nitrogen, diseases and quality?

56 Conclusion Over the last 20 years or so, agronomic research has contributed significantly to on-farm crop production changes that are positive in terms of economics and sustainability The need for this research will continue into the future, and may intensify While advances in biotechnology may indeed revolutionize crop production in the 21 st century, proper stewardship of the land through appropriate agronomic practices will always be a major priority

57 Acknowledgments Alberta Canola Producers Commission, Alberta Barley Commission, Alberta Agricultural Research Institute, Canadian Wheat Board, RAHR Malting, Matching Investment Initiative of Agriculture & Agri-Food Canada Superb scientists, technicians and extension and industry personnel at various locations across western Canada