The remarkable improvements in Australian mixed farming

Transcription

1 The remarkable improvements in Australian mixed farming John Angus Honorary Research Fellow, CSIRO Plant Industry, Canberra and Wattle Flat, Stockinbingal Hector and Andrew Stewart Memorial Lecture, University of Western Australia, 18th March 2011

2 Average dryland farm land area, crop area and livestock number Farm area Land area (ha) Cattle number Sheep number Sheep number Cattle number 500 Crop area ABARE data

3 Australian wheat yields, Annual 5-year running mean Trends N fertiliser in Sth. Aust Break crop (canola) in Sth. Aust Break crop(lupin) in WA Yield (t/ha) Nutrient exhaustion Superphosphate New cultivars Fallowing Legume nitrogen Better rotations Mechanisation Semidwarf cultivars Selective grass herbicides Millenium drought Aust. J. Exp. Agric 41,

4 Wheat yield gap below the water-limited potential 6 China Loess Plateau Mediterranean Basin North American Great Plains SE Australia 5 Yield (t/ha) n = Evapotranspiration (mm) Aust. J. Agric. Res 57,

5 Contributions to increased wheat productivity Breeding Timing Disease resistance Stress tolerance ( / search: wheat & drought) Stature semi dwarfs Grain quality Crop management Timing Nutrition fertilisers and pasture-n Crop sequences rotation Tillage and stubble management Correcting soil acidity - liming Weed control herbicides Disease control - fungicides Climate change Adoption - innovation

6 Studies evaluating the contribution of crop management to yield increase Reference Region Percentage of yield improvement due to management Warren (1971) Southern NSW 100 Russell (1973) South Australia 78 Greb (1979 USA 70 Ridley and Hedlin (1980) Canada 85 O Brien (1982) Victoria 67 Schmidt (1984) USA 47 Perry and D Antuono (1989) Western Australia 71 Bell et al (1994) Mexico 50 Anderson and Impiglia (2002) Western Australia 68 Horie (2004) Rice, Japan 100 Mackay et al (2010) UK winter wheat Mackay et al. (2010) UK winter wheat Average 65

7 Trends of WA wheat yield on farms and in variety trials Variety yields by year of release (Perry and D'Antuono 1989) Yield (t/ha) WA wheat yields (5-year running mean)

8 Western Australian wheat and barley yields, Yield (t/ha) Wheat Barley Yield ratio (wheat/barley)

9 Wheat yields on farms and variety trials in the Victorian Wimmera 4 3 Free Gallipoli Federation Ghurka Free Gallipoli Summit Kewell Meering Cocamba Yield (t/ha) 2 Federation Pinnacle Ghurka Pinnacle Summit Meering

10 Contributions to grain yield GRDC R&D investments in Breeding Slice 2 Management Varieties $55.1m Practices $36.7m New Products $11.2m Communications $8.9m Others $3.4m

11 Middle-distance speed of racehorses (selectively bred) and human males (not selectively bred) 5 Time (m:s) 4 Melbourne Cup World mile record

12 Adoption of N fertiliser in Australia is recent World nitrogen fertiliser (x 10 6 t N) Australian nitrogen fertiliser (x 10 3 t N) World Australia 200

13 Wheat yield response to topdressed nitrogen fertiliser Yield response to 40 kg N/ha topdressed ShootDens vs YldResp Shoots / m 2 After break crop No break crop

14 2 1 Fertiliser N use (million tonnes) Canola area (million ha) Canola triggered the use of lime and nitrogen fertiliser Fertiliser N use NSW lime use Canola area Lime in NSW (million tonnes)

15 NSW canola and lime use Lime ( '000 tonnes) Canola area ('000 ha)

16 Prime hard wheat experimental sites Mullawa Morawa Dalwallinu Kalannic Mukinbudin Merredin Varley Salmon Gums Lake Grace Cascade Minnipa Moree Gulargambone Gilgandra Ariah Condobolin Loxton Park Thuddungra Walpeup Kyalite Nangus Horsham

17 Grain quality: screenings of wheat grain in 3 regions Screenings (%) North SE West Grain protein (%)

18 Increased wheat production Rotations per farm since 1990 Crop sequences Break crops

19 One of 700 assessments of break crops Wheat after wheat 2 t/ha Wheat after canola 5 t/ha

20 Possible mechanisms of the break- crop effect Root disease absence of host or biofumigation? Foliar disease Residual water Residual nutrients Biologically fixed N residues Hydrogen fertilisation Suppression of arbuscular mycorrhizal fungi (AMF) Better weed control / earlier sowing

21 Take-all fungus in wheat roots

22 Suppression of take-all by brassica and linseed tissue biofumigation Plant and Soil 162,

23 Hydrolysis of glucosinolates releases isothiocyanates N - - OSO3 Glu Glu - S - C R-N=C-S \ R Glucosinolate Isothiocyanate R = phenylethyl (generally present in Brassica roots) = propenyl (present in mustard roots)

24 Hydrogen fertilisation Nodule N 2 +6H + 6e - 12 ATP 12 ADP 2NH 3 Nitrogenase 3H + 1.5H 2 3e - 6 ATP 6 ADP 3e - 3H + Uptake Hydrogenase (HUP+)

25 Hydrogen fertilisation Nodule N 2 +6H + 6e - 12 ATP 12 ADP 2NH 3 Nitrogenase 3H + 1.5H 2 3e - 6 ATP 6 ADP Diffuse Energy = 5-6% of daily photosynthesis H 2 Many symbioses are HUP-

26 Break crops regulate mycorrhizal colonisation of wheat... Previous crop Δ wheat field pea canola Filled symbols no P Open symbols 17 kg P/ha Plant and Soil (2005) 270:

27 Break-crop effect of oats (0.47 t/ha) 10 Yield of wheat after oats (t/ha) Sweden Australia Other Yield of wheat after wheat (t/ha) Australian Agronomy Society 2008

28 Break-crop effect of canola (0.8 t/ha) 10 Yield of wheat after canola (t/ha) Australia Other countries Yield of wheat after wheat (t/ha) Australian Agronomy Society 2008

29 Break Yields crops benefits of break crops for wheat Break crop No. of obs. Yield benefit (t/ha) Wheat yield Barley Oats Canola Mustard Flax Field pea Fababean Lupin Chickpea Lentil

30 Lupins give a greater break-crop benefit than field pea 8 Yield of wheat after legume (t/ha) After field pea After narrow-leaf lupin Yield of wheat after wheat (t/ha)

31 Effect of 3 different break crops on wheat yield Barley Oats Canola Mustard Flax Field pea Lupin Wheat Number

32 Sources of the break-crop effect and estimates of their contribution to additional yield for a 4 t/ha wheat crop Mechanism Additional yield (t/ha) Take-all suppression 0.5 Suppression of other root diseases 0.3 Net N benefit of canola 0.1 Hydrogen fertilisation by legumes 0.4 Suppression of AMF by non-hosts 0-0.1? Net N benefit of legumes 0.5

33 Adoption of break crops (particularly canola) triggered: Liming Increased yield of following cereals More extraction of soil water and N by wheat More reliable cereal response to N fertiliser Lime helped the return of lucerne and barley

34 Twenty-years of conservation cropping at Harden

35 Yield response to direct drilling in relation to seasonal rainfall Yield diff (RDD-BC) (t/ha) Yield gain Longterm Average Yield loss Growing season rainfall (mm)

36 Wheat response to conservation cropping at Harden DC30 Biomass (g/m 2 ) Yield (t/ha) * Burn/Cult Retain/DD * * * * * * * * * * * * * *

37 Yield (t/ha) of wheat grown every second year, Harden Burn No burn Till No till

38 Grazing vegetative crops

39 Effects of grazing vegetative crops with sheep (~20 dse /ha for days) delayed maturity (1 day s flowering delay per ~4 grazing days deferred water use poor nitrogen uptake after grazing? reduced lodging of early-sown crops yield response - 4 ± 25%

40 Wheat yield increased by grazing because water use is deferred until after flowering 2.27 t/ha 2.80 t/ha

41 Reintegrating livestock with cropping Opportunities Perennial pastures Grazed crops Failed crops as a feed source Wool-shedding sheep (Dorper & Wiltipolls) Fewer pests (flies, worms, PETA) Transporting northern cattle south? Problems Breeding stock on grazed crops Excess paddock size Less shade

42 The County Agent, Norman Rockwell, 1948 Innovation and adoption

43 Adoption: Delay of ~30 years between research and adoption on farms. Alston et al Innovation: users of products and services both firms and individual consumers are increasingly able to innovate for themselves. von Hippel 2005

44 Acknowledgements Wal Anderson Bill Bowden Tony Fischer Tony Good John Kirkegaard Lars Ohlander John Oliver John Passioura Mark Peoples Megan Ryan Victor Sadras Anthony van Herwaarden Jim Virgona

45 Nitrogen supply and demand by a wheat crop 3 N supply and demand (kg ha -1 day -1 ) 2 1 Supply Demand 0 J F M A M J J A S O N D

46 Grain quality: test weight of wheat grain in 3 regions 100 North Test weight (kg/hl) SE West Grain protein (%)