5th World congress of conservation agriculture               Incorporating 3rd farming systems design conference      Irri...
Introduction           Major Agricultural Challenges                       Land            Water UseWater Scarcity        ...
1. Water Scarcity Issuesa)     Population-      Population growth increase pressure on       available water resources-   ...
2. Land Degradation Issuesa) Intensive cultivation-    Damages soil physical, chemical and     biological health-     Caus...
3. Water Use Efficiency (WUE) Issues  • WUE is a generic term used for indicating water use in crop production.    (GPWUI,...
Research opportunities     •    Past NCEA studies identified furrow irrigation (Ea) 30-60% and reasons were          attri...
Objectives:   Evaluate the irrigation performance of   existing PRB farming systems under   Australian vertisol soil condi...
Methodology   Field trials:       Site 1: Marinya farm, Cambooya (Soybean)       Site 2: Bandawing farm, Dalby (Cotton) ...
Layout of Sentek (enviroscans) sensors placed across         the bed for logging wetting front penetration into bed       ...
Results                                                    1200                                                           ...
Figure : Cotton crop at Bandawing farm near Dalby with (a)          measured irrigation 1; (b) measured irrigation 2 with ...
Table : Impact of irrigation management strategies on current irrigation performance of          two sites under black cra...
Figure : Relationship of optimum Tco vs. Q, average values of two          irrigations, with predicted irrigation performa...
4.50                                                                    1 L/s                   4.00                      ...
Figure : Temporal and spatial variations in lateral water infiltration across 2 m wide          bed at (a) 33cm, (b) 67cm ...
ConclusionsThe current irrigation management is not optimal , often longer Tco and lower Qthan optimal are practiced unde...
Data recording                        Bulk Density and soil moisture data1st Irrigation at Cambooya            2nd irrigat...
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Irrigation performance and seasonal changes under permanent raised beds on Vertisol in Queensland, Australia. Ghani Akbar

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Irrigation performance and seasonal changes under permanent raised beds on Vertisol in Queensland, Australia. Ghani Akbar

  1. 1. 5th World congress of conservation agriculture Incorporating 3rd farming systems design conference Irrigation performance and seasonal changes under permanent raised beds on Vertisol in Queensland, Australia Ghani Akbar (NCEA, USQ Toowoomba, Qld) Professor Steven Raine (FOES, USQ Toowoomba, Qld) Dr Allen Jack McHugh (NCEA, USQ Toowoomba, Qld) Mr Greg Hamilton (Maximum Soil & Water Productivity Pty Ltd. Perth WA)26 to 29th September, 2011 1
  2. 2. Introduction Major Agricultural Challenges Land Water UseWater Scarcity Degradation Efficiency Issues Issues Issues Population Intensive Irrigation growth cultivation management Inefficient Seasonal Agronomic irrigation changes management systems 2
  3. 3. 1. Water Scarcity Issuesa) Population- Population growth increase pressure on available water resources- (2000-5000 Litres/day) is required to support a single person diet Figure : Global water withdrawal by sector Source: WWI from P.H. Gleick (1993),Water in crisis, Oxford University Pressb) Inefficient irrigation systems- Only 20% global cultivated land is irrigated- Irrigated lands produce 40% world food- Utilise 70% of global water withdrawal- Inefficient & poor irrigation management(There is need for the efficient use of available water Figure : Percentage of cultivated area equipped for irrigationto meet the growing food, fibre & domestic needs) Source: FAO-AQUASTAT Introduction 3
  4. 4. 2. Land Degradation Issuesa) Intensive cultivation- Damages soil physical, chemical and biological health- Causes erosion, crusting, sealing, loss of OM & nutrients thus productivity decline Intensive cultivationb) Seasonal changes- Wetting, flowing water, rainfall hammering slaking, shrinking, swelling & subsidence Fresh bed Subsided bed- Affect soil hydro-physical properties which also affect irrigation & crop performance- Maintenance cost also increase( There is a need for adoption of soil friendly Seasonal changesagronomic practices for improving soil health& stability on sustainable basis) Introduction 4
  5. 5. 3. Water Use Efficiency (WUE) Issues • WUE is a generic term used for indicating water use in crop production. (GPWUI, IWUI, CPWUI,...) (Burett Purcell & associate, 1999) a) Irrigation management • Type of irrigation system Irrigation Agronomic Issues Issues • System efficiency & uniformity (Ea, Er, DU etc) b) Agronomic management Water Use • Land management & tillage Efficiency • Cropping management • WUE improvement is the key for producing more food with less water (Under the prevailing water scarcity and declining land productivity situations WUE improvement on sustainable basis is essential for future food security)Introduction 5
  6. 6. Research opportunities • Past NCEA studies identified furrow irrigation (Ea) 30-60% and reasons were attributed to excessive deep drainage losses, poor irrigation management and field design issues. They identified 85-95% achievable (Ea) by better irrigation management & field design. (Raine & Bakker, 1996; Smith et al. 2005) • Similarly improved soil amelioration (i.e. better structure, porosity, hydraulic conductivity) were reported under the rain-fed Vertosol soil condition by adopting zero till control traffic farming. (Tullberg, 1988, McGarry, 2001, McHugh et al. 2003) • However, evaluation of current PRB farming system affected by variable bed furrow configurations, soil management, subbing and their impact on irrigation management strategies were rarely considered.Literature Review 6
  7. 7. Objectives: Evaluate the irrigation performance of existing PRB farming systems under Australian vertisol soil conditions To identify potential for lateral wetting front infiltration from furrow to centre of bed 7
  8. 8. Methodology Field trials: Site 1: Marinya farm, Cambooya (Soybean) Site 2: Bandawing farm, Dalby (Cotton) Data collection  Tillage and field information  Irrigation inflows Advance Sensors  Flow advance along furrows  Runoff at tail end  Furrow geometry & slope (Use of IRRIMATETM tools) Use of IPARM & SIRMOD for performance evaluation Flume with flow meter Soil moisture movement across the bed (Using assembly of Sentek (Enviroscans) for lateral wetting front infiltration (Cambooya) Use of SIRMOD for irrigation performance optimization (Er≥ 85%, Water arrival to furrow tail, maximum water saving) Siphon with flow meter 8
  9. 9. Layout of Sentek (enviroscans) sensors placed across the bed for logging wetting front penetration into bed centre at Marinya farm CambooyaMethodology 9
  10. 10. Results 1200 1000 Advance time (min) Irrigation 1 800 Irrigation 2Site 1:Irrigation 1: Narrow 600furrows, loose soil 400Site 2: 200Irrigation 2: Cracking due 0dry soil conditions 200 0 100 300 400 500 Distance along furrow (m) Figure: Measured advance curves of two irrigations to soya bean at Marinya farm Cambooya (bars shows +/- standard deviation) 700 Irrigation 1 Flow advance time (min) 600 Irrigation 2 500 400 300 200 100 0 0 100 200 300 400 500 Distance along furrow (m) Figure : Measured advance rate during two irrigations of cotton crop at Bandawing farm, Dalby (bars shows +/- standard deviations) 10
  11. 11. Figure : Cotton crop at Bandawing farm near Dalby with (a) measured irrigation 1; (b) measured irrigation 2 with flow crossing the bed through cracks due to dry soil conditionsResults 11
  12. 12. Table : Impact of irrigation management strategies on current irrigation performance of two sites under black cracking Vertisol soils in southern Queensland, Australia, (values in brackets are +/- standard deviation). Water Q Tco Ea Er Inflow Site Strategies DU (%) saving* (L.s-1) (min) (%) (%) (m3/ha) (%) Farmer 1.94 1100 73 100 90 1393 managed (0.1) (61) (6) (0) (3) (113) Cambooya 1. Tco 1.94 921 80 92 74 1167 16.2 optimised (0.1) (84) (8) (2) (3) (137) 2. Tco & Q 3.25 425 98 85 88 879 37 optimised (0.7) (88) (1) (0) (3) (11) Farmer 2.54 635 79 97 87 1062 managed (0.1) (64) (8) (2) (1) (84) Dalby 1. Tco 2.54 473 97 88 77 790 25.6 optimised (0.1) (121) (1) (3) (2) (186) 2. Tco & Q 3.125 370 97 85 82 762 28.3 optimised (0.2) (40) (3) (0) (4) (125) *Water saved as compared to farmer practiceResults 12
  13. 13. Figure : Relationship of optimum Tco vs. Q, average values of two irrigations, with predicted irrigation performance (Ea, Er and DU) at two sites.Results 13
  14. 14. 4.50 1 L/s 4.00 2 L/s 3 L/s 3.50 4 L/s 3.00 5 L/s Tco/Ta 2.50 2.00 1.50 1.00 0.50 0.00 0 100 200 300 400 500 600 Furrow length (m) Figure: Effect of furrow length and inflow rate on the ratio (between time to cut-off and time of advance to tail end) for achieving Er≥ 85% and flow arrival at tail end (Cambooya: irrigation 1).Results 14
  15. 15. Figure : Temporal and spatial variations in lateral water infiltration across 2 m wide bed at (a) 33cm, (b) 67cm and (c) 100cm from furrow centre during summer 2010 (soya bean) at Cambooya, Qld, Australia.Results 15
  16. 16. ConclusionsThe current irrigation management is not optimal , often longer Tco and lower Qthan optimal are practiced under farmer managed conditions.Majority of current soil management/raised bed renovation practices are notoptimal leading to low irrigation performance and poor water use productivity.The current bed furrow configurations are largely not optimal causing poorirrigation performance and crop establishment leading to low WUP.Subbing is not a significant problem under the current irrigation management ofAustralian farms with lengthy furrows and prolonged irrigation cut-off times butcan affect crop performance especially at tail end if infiltration opportunity time isnot sufficient (i.e. <5 hours in the case evaluated). 16
  17. 17. Data recording Bulk Density and soil moisture data1st Irrigation at Cambooya 2nd irrigation Soybean crop The End Thanks all of you 17

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