2015/09/29 INTRODUCTION. INTRODUCTION...(continue) Why is irrigation necessary?

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1 215/9/29 INTRODUCTION Why is irrigation neessary? To make the ultivation of rop more profitable i.e. higher yields = higher profits! Summer rainfall to low in most areas for sustainability What determine a rops water requirement? Fators in the environment surrounding the rop eg. limate, soil harateristis and onditions, wetted soil surfae, et. Fators and harateristis of the plant itself e.g. planting denities, plant orientation, total exposed leaf area, et. * INTRODUCTION...(ontinue) Growers in the South Afrian Wine Industry fored to produe high yields to stay eonomially viable not neessarily ompensated for higher quality lower yields produed Water shortage, ost and future alloations more and more unertain!!! 1

2 21 July 22 (September 214???) 21 July 23 (September 215???) HOW CAN WE AS GRAPE GROWERS BUFFER OURSELFS AND PREPARE FOR POSSIBLE CHANGES IN WATER AVAILABILITY? WE MUST STRIVE TO PRODUCE GRAPES UNDER BETER WATER USE EFFICIENCY CONDITIONS!!! 2

3 IRRIGATION WATER USE EFFICIENCY (IWUE) IWUE = Grapes produed per hetare (kg) Water irrigated during prodution season (m 3 ) OBJECTIVE OF PRESENTATION Brief disussions around the diret and/or effets of some aspets with respet to the improvement of IWUE, i.e.: 1. Irrigation strategies 2. Soil preparation 3. Irrigation system 4. Soil surfae management 5. Plant material (Clone) 6. Alternative trellis systems/canopy management 3

4 11 7 Relative yield (% of maximum) t/ha 15.4 t/ha 66 % 1.8 t/ha 2.3 t/ha 44 % 2.1 t/ha 24.5 t/ha 39 % 2.8 t/ha 25.6 t/ha Irrigation, rain and soil water holding apaity (mm) Relationship between irrigation, rain and potentially stored water in the root zone and relative yield, as well as potential wine quality of Shiraz near Robertson (sandy loam soil) and Lutzville (wind blown sandy soil). 38 % Potential wine quality (%) Relative yield (% of maximum) Irrigation, rain and soil water holding apaity (mm) Relationship between irrigation, rain and potentially stored water in the root zone and relative yield, as well as potential wine quality of Merlot near Wellington (sandy lay loam soil), Ashton (alluvial sandy loam) and Lutzville (wind blown sandy soil) Potential wine quality (%) Example of IWUE alulation 1) 24.9 tons of grape produed per hetare by irrigating 54 mm throughout season Example of IWUE alulation 2) 13.9 tons of grape produed per hetare by irrigating 12 mm throughout season 24.9 tons grapes = 24 9 kg and 54 mm = 5 4 m tons grapes = 13 9 kg and 12 mm = 1 2 m 3 IWUE = 24 9 kg 5 4 m 3 IWUE = 13 9 kg 1 2 m 3 = 4.6 kg/m 3 = 11.6 kg/m 3 4

5 Example of IWUE alulation EXAMPLE 1 EXAMPLE 2 Irrigation (m 3 ) Yield (kg) IWUE (kg/m 3 ) IWUE of example 2 produed 2.5 times more grapes per unit of water i.e. potentially ould produe 62.6 t/ha with 5 4 m 3 water in 4.5 hetares Irrigation and rain (mm) T1 T2 T3 T4 T5 T6 T7 T8 T9 T1 3-4% 7-8% Prevéraison 7-8% 3-4% 3-4% CDI 7-8% Postvéraison 7-8% (1) Soil profile refilled to field apaity at véraison (2) Partial profile refill >9% >9% >9% CDI CDI (1) 7-8% 3-4% CDI >9% CDI CDI PPR (2) Figure The average amount of rain and irrigation applied to ten irrigation strategies during the 26/7, 27/8 and 28/9 growing seasons on Shiraz/11R near Robertson. Yield (t/ha) a ab b d d de e e T1 T2 T3 T4 T5 T6 T7 T8 T9 T1 Irrigaion water prodution (kg/m 3 ) a b d d d T1 T2 T3 T4 T5 T6 T7 T8 T9 T1 3-4% 7-8% Prevéraison 7-8% 7-8% >9% >9% >9% CDI CDI (1) 7-8% 3-4% 7-8% Prevéraison 7-8% 7-8% >9% >9% >9% CDI CDI (1) 7-8% 3-4% 3-4% CDI Postvéraison 7-8% 3-4% CDI >9% CDI CDI PPR (2) 3-4% 3-4% CDI Postvéraison 7-8% 3-4% CDI >9% CDI CDI PPR (2) (1) Soil profile refilled to Field apaity at véraison (1) Soil profile refilled to Field apaity at véraison (2) Partial profile refill (2) Partial profile refill Figure 4.6 Effet of ten irrigation strategies on the mean yield of Shiraz/11R in a fine sandy loam soil near Robertson during the 26/7, 27/8 and 28/9 seasons. Figure 4.6 Effet of ten irrigation strategies on the mean irrigation water prodution of Shiraz/11R in a fine sandy loam soil near Robertson during the 26/7, 27/8 and 28/9 seasons. 5

6 Sugar ontent ( B) % PAW Depletion Berry mass (g) % PAW Depletion Target.5 3% PAW Depletion 9% PAW Depletion Days after bud break Days after bud break Shallow vs. deep soil preperation E.g. 1 mm/m water holding apaity A B m Extra soil water available 7 m 12 m 6

7 A B m Extra soil water available 7 m 12 m Available water = 1 mm/m.7 m = 7 mm = 7 litre per m 2 Available water = 1 mm/m 1.2 m = 12 mm = 12 litre per m 2 Irrigation systems Irrigation systems have inherent water appliation effiienies due to water losses that our while irrigations are being applied Irrigation systems... Evaporation losses an be redued onsiderably if the irrigation water is only applied to a fration of the irrigated land Irrigation system effiienies as proposed by Ley (1994). Irrigation system Appliation effiieny (%) Flood (border, rill) 45 to 6 Sprinklers - portable 6 to 7 Miro-sprinklers 75 to 85 Drip (trikle) 85 to 9 Subsurfae drip 9 to 95 Full surfae vs. partial surfae wetting systems??? 7

8 Two most important proesses of water loss: Transpiration 5 Effet of limate on evaporation 4 Phase I Phase II Evaporation Cumulative E s (mm) Time (days) Evaporation Water loss through evaporation E.g. Overhead or miro sprinkler full surfae wetting E.g. Drip irrigation partially wetting Transpiration Water loss through plant E.g. Overhead or miro sprinkler full surfae wetting E.g. Drip irrigation partially wetting 25 mm per,6 m 25 mm per,6 m 25 mm per,6 m 25 mm per,6 m 5 mm = 17 liter 5 mm = 4 liter 6 liter 6 liter 2 mm 2 mm 23 mm 18 mm 8

9 Irrigation systems... Evaporation losses an be redued onsiderably if the irrigation water is only applied to a fration of the irrigated land Evapotranspiration (mm/d) Drippers Miro-sprinklers Transpiration Evaporation Jul Aug Sep Ot Nov De Jan Feb Mar Apr May Jun Effet of irrigation system on evapotranspiration of table grapes near Augrabies. OBJECTIVE OF PRESENTATION Brief disussions around the diret and/or effets of some aspets with respet to the improvement of IWUE, i.e.: 1. Irrigation strategies 2. Soil preparation 3. Irrigation system 4. Soil surfae management 5. Plant material (Clone) 6. Alternative trellis systems/canopy management Evaporation (mm d -1 ) Effet of soil surfae onditions on evaporation 1 Bare soil a a 8 a a b 6 4 d d d de de 2 e de e e e Position number Soil with mulh d d d d d d d d d 1 e de e e de 3 Days after irrigation Position number Also soil olour through radiation refletion or aumulation Es (mm) Effet of soil surfae onditions on evaporation Effets of mulhing and tillage on E s following irrigation No tillage Clean tillage 5 Mulh - 4 t/ha Mulh - 8 t/ha Days after irrigation 9

10 OBJECTIVE OF PRESENTATION Brief disussions around the diret and/or effets of some aspets with respet to the improvement of IWUE, i.e.: 1. Irrigation strategies 2. Soil preparation 3. Irrigation system 4. Soil surfae management 5. Plant material (Clone) 6. Alternative trellis systems/canopy management Clone Plant material an also determine the mass of fruit produed per unit volume irrigation water Non-lone Effet of plant material on IWP of furrow irrigated Thompson Seedless grapevines near Upington. Data are means for three seasons. Plant material Irrigation applied (m 3 ) H5 lone Yield (t/ha) IWP (kg/m 3 ) Non-lone H5 lone E.g. SHIRAZ - SH1 vs. SH9 Effet of leaf area on transpiration Effet of leaf area on transpiration Transpiration (l day -1 grapevine -1 ) Horisontal trellis systems (y =.328x R =.91) VertikVertial trellis systems (y =.185x +.16 R =.873) Transpiration (ml houur -1 grapevine -1 ) Bunhes removed, leaf area = 9,96m 2 per grapevine Bunhes left, leaf area = 1,86m 2 per grapevine Bunhes remove Leaf area per grapevine (m 2 ) 12: : 12: : 12: : 12: : 12: : 12: Time (hour) 1

11 215/9/29 6. Alternative trellis systems Is it possible to improve IWUE, yield and wine quality at the same time? Yes, if you adapt other praties, e.g. trellis system. 65 m 7 m Six-strand hedge Different irrigation strategies in ombination with different anopy management manipulations performed on Shiraz/11R in a fine sandy loam soil near Robertson. 6. Alternative trellis systemsj... Sukered tuked 3% PAW depletion Two-tier hedge Two-tier hedge 584 mm 47 mm 21.1 t/ha 3.1 t/ha 26.7 t/ha 49.4% 49.7% 58.7% 3.6 kg/m3 5.2 kg/m3 6.6 kg/m3 Six-strand hedge Irrigation: 584 mm Yield: Quality: IWP: Two-tier hedge 6% PBW depletion 9% PBW depletion tuked Sprawl T1 T2 T3 T4 T5 T6 T7 T8 T9 T1 Meanial pruned 11

12 The effet of ten different irrigation strategy and anopy management ombinations on the irrigation amounts applied to Shiraz/11R in a fine sandy loam soil near Robertson (means of 211/12, 212/13 and 213/14 seasons). The effet of ten different irrigation strategy and anopy management ombinations on the yield of Shiraz/11R in a fine sandy loam soil near Robertson (means of 211/12, 212/13 and 213/14 seasons). Irrigation (mm)* Yield (t/ha) b 25.4 a 23.2 ab 17.9 d 22.4 ab 16.5 de 15.1 de 14.4 de 13.1 e 22.3ab 1 5. T1 T2 T3 T4 T5 T6 T7 T8 T9 T1 Irrigation a. 3% PAW depletion a. 6% PAW depletion a. 9% PAW depletion. T1 T2 T3 T4 T5 T6 T7 T8 T9 T1 Irrigation a. 3% PAW depletion a. 6% PAW depletion a. 9% PAW depletion Canopy manipulation Sukered Sukered Sukered Meahnial pruning Canopy manipulation Sukered Sukered Sukered Meahnial pruning * Multiply with 1 to get m 3 /ha The effet of ten different irrigation strategy and anopy management ombinations on the irrigation water use effiieny (IWUE) of Shiraz/11R in a fine sandy loam soil near Robertson (means of 211/12, 212/13 and 213/14 seasons). IWUE (kg/m 3 ) b 1.4 b 9.5 b 13.8 a T1 T2 T3 T4 T5 T6 T7 T8 T9 T1 Irrigation a. 3% PAW depletion a. 6% PAW depletion a. 9% PAW depletion Yield (t/ha) 4 35??? 3??? VSP 1 Non VSP 5 Mehanial Pruning Irrigation (mm) Canopy manipulation Sukered Sukered Sukered Meahnial pruning 12

13 The effet of different irrigation strategies in ombination with different anopy management manipulations performed on the IWUE of Shiraz/11R in a fine sandy loam soil near Robertson. Sukered tuked tuked Sprawl Meanial pruned 3% PAW depletion ?? 6% PBW depletion ?? 9% PBW depletion Conlusions - Don t be in denial water alloations won t inrease BE PREPARED! - We must be prepared to adapt to produe grapes in an eonomially viable manner - Prodution plateau with higher irrigation volumes rather use aess water on extra hetares to inrease IWUE Conlusions - Lower yield losses with irrigation strategies that ripen earlier - Deeper soil preparation allows higher water holding apaities derease irrigation requirement - Loalised irrigation systems deliver water more effetive and lower evaporation losses Conlusions - Clones with high yield apaities inrease IWUE - Trellis systems and/or anopy manipulation appliations to inrease yield per area higher IWUE 13

14 Aknowledgements: -, DTS and for partial funding; - SA for irrigation equipment; - Mrss Johan and Pierre Brouwer, Pierre Blake and Hannes and JC Erasmus for the use of their vineyards; and Thank you - ARC Infuite-Nietvoorbij Irrigation personnel. 14