Presentation - Irrigation Australia

Aerated water irrigation on table grapes Surya P. Bhattarai, David J. Midmore and Lance Pendergast

Introduction & outline 

Background to oxygation research

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Introduction to concept “Oxygation”, what is it?

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Brief overview of research to date

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Grapes

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Future focus / activities

Plant / oxygen 

Active roots are major sinks for oxygen in plants -consume about x 9 their volume of oxygen gas each day

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In plant cells, oxygen participates in over 200 different cellular chemical reactions

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95 % oxygen consumption is devoted towards energy needs (production of ATP) from carbohydrates)

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Poor soil aeration is a major abiotic stress that limits the success of crops

Bigger wetting front in clay

Wetting front ubiquitous of SDI

Left: Wetting front after 10 h irrigation @ Right: Simulated wetting front after 12 h irrigation applied at 1.25 l h-1 1.7 l h-1 from simulated emitter at 0.30 m from emitter installed at a depth of 0.40 m in a sandy (left) and clay in a loamy soil (Battam et al., 2003). (right) soil (Source: Thorburn et al., 2001)

Oxygation@CQU

Research for Impact (Concept testing-industry adoption) Driver: Improving crop water productivity Issue: Impeded soil aeration associated with irrigation Approach: Aerated water irrigation (oxygation)

Theory-1

M-Air injector

Seair

Mixaerator

Test Verify

Adopt Improve

Diversify

Field trials, research outreach and industry collaboration for oxygation of annual and perennial crops

6

Cotton field trials Location: Nyang, Emerald, Soil: Vertosol, Irrigation: SDI, Trt: Oxygation & control, Replication:~6, Plot size:0.4 ha, Paddock: 0.4 x 12=4.8ha, Air injector: 12% by MI-1583, Irrigation: 6.3ML/ha Lint yield (bales/ha) in vertosol over seven seasons

Results: 14.7% higher lint yield

Pineapple @Valley Syndicate, Yeppoon Planting:24/10/07 (GC-2), Oxygation:14/03/08, Harvest:05/01-17/04/09, Mazzei-1583, Drip-Hydro PC 16/20 0.3m 1.2L/hr

Treatments

1Harvested

yield (t/ha)

2Industry

yield (t/ha)

Phytophthora (% plants)

Main crop

Ratoon

Total

Main crop

Ratoon

Total

Control

68.20

38.17

106.37

50.92

18.25

69.17

4.9

Oxygation

79.60

54.11

133.71

53.08

20.18

73.26

3.0

Noirrigation

71.30

19.07

90.37

49.50

16.42

65.92

10.5

P value

0.005

0.001

0.032

0.295

0.051

0.076