Allan Fulton, Irrigation and Water Resources, Farm Advisor, Tehama, Glenn, Colusa, and Shasta Counties

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1 Allan Fulton, Irrigation and Water Resources, Farm Advisor, Tehama, Glenn, Colusa, and Shasta Counties 1

2 Trends in California s almond and walnut industries Research impacts and challenges Irrigation scheduling tools Production Water use efficiency 2

3 780,000 acres of bearing almonds in 2012 An increase of 250,000 acres in last decade Statewide average production up 30 %, 1750 to 2285 lbs/ac 245,000 acres of bearing walnuts in 2012 An increase of 50,000 acres in last decade Statewide average production up 75 %, 1.2 to 2.1 tons/ac an additional 100,000 acres of non-bearing and new plantings of almond and walnut in 2012 On average, demand and prices of both commodities increasing even though production increases, expect more expansion o o Heart healthy foods and other Growing middle class worldwide 3

4 Source: DWR NRO Land & Water Use Section 4

5 Seven year study in bearing walnuts This study documents the effects of managing on-farm irrigation practices, with and without using CIMIS information, in a Kings County walnut orchard. In this example, increased water use, increased production, and increased profits were experienced as a result of implementing CIMIS information Implementing CIMIS at the farm level: A grower s experience in walnuts. Fulton, Beede, and Phene. Sept-Oct California Agriculture 5

6 Changes in almond and walnut culture New varieties and rootstocks Different orchard designs Changes in pruning and canopy management, less pruning More micro irrigation and fertigation Changes in grower support Internet and mobile communication More involvement from private sector Advanced research tools among public sector More holistic perspectives So, what have been the impacts and what challenges lie ahead? 6

7 A 2012 survey of almond growers More adoption of scientific methods to decide when to irrigate and how much water to apply. 47 % - Use automated soil moisture monitoring to aid decision making 64 % shovel or auger 7

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9 Dielectric sensors and radio telemetry for monitoring soil moisture depletion 9

10 4/15 4/25 5/5 5/15 5/25 6/4 6/14 6/24 7/4 7/14 7/24 8/3 8/13 8/23 9/2 9/12 9/22 10/2 10/12 10/22 11/1 11/11 Soil water content (in/ft) Midday Stem Water Potential (bars tension) 1-May 11-May 21-May 31-May 10-Jun 20-Jun 30-Jun 10-Jul 20-Jul 30-Jul 9-Aug 19-Aug 29-Aug 8-Sep 18-Sep 28-Sep 8-Oct 18-Oct 28-Oct inches 18 inches 30 inches 42 inches 54 inches 66 inches Fully irrigated baseline Weekly measurement of soil moisture depletion in Tehama County walnut Orchard Weekly measurement of orchard water status in same walnut Orchard 10

11 A 2012 survey of almond growers More adoption of scientific methods to decide when to irrigate and how much water to apply. 47 % - Use automated soil moisture monitoring to aid decision making 64 % shovel or auger 44 % - Consider real-time ETc when making decisions Prefer real-time ETc to historic or normal year averages 60 % know water application rates of irrigation systems ETc = (ETo x Kc) Applied Water = ETc Account for contribution from dormant season soil storage Account for effective in-season rainfall 11

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13 Kern Bearing Almonds (1000 ac) & Revenue ($100/ac) Nut Meat Yield (lb/ac) Weekly Eddy Covariance Crop Coefficient (Kc) DATE Almond Kc Almond Kc Mar 1-15 NA 0.54 Mar Apr Apr May May : 52.8 in 2009: 61.5 in 2010: 54.9 in 2011: 50.3 in 2012: 48.2 in June June July July Aug Aug Sept Sept Oct Oct Nov /1 1/29 2/26 3/26 4/23 5/21 6/18 7/16 8/13 9/10 10/8 11/5 12/3 12/31 Bearing (1000 acres) Gross Revenue ($100/ac) Meat Yield (lb/ac) 150 Cultural Yield 3000 Years Practice (lb/ac) (2008 ET measured 3/19to 11/ through 2012 are for the full year.) Source: Sanden and Snyder, Short Prune Long Prune More Water & N Total ETc

14 Kc (ETc/ETo) Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct DWR Northern District Historic Almond Kc 2008 Surface Renewal Almond Kc, Tehama County 2009 Surface Renewal Almond Kc, Tehama County 2010, Eddy Covariance, Almond Kc, Tehama County 14

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16 1-Feb 3-Mar 2-Apr 2-May 1-Jun 1-Jul 31-Jul 30-Aug 29-Sep 29-Oct Actual Coefficient (K a =K c XK s ) Avg Kc Values: Source 2011 Tehama County Eddy Covariance Study (Source: Fulton, Little, and Snyder) Avg Kc Values: Source 1996 Walnut Manual 16

17 Conventional Theory Single tree reps? Single year orchard or plot averages Multi year plot averages Source: Bruce Lampinen, UC Davis Statewide Almond and Walnut Specialist,

18 A 2012 survey of almond growers More adoption of scientific methods to decide when to irrigate and how much water to apply. 47 % - Use soil moisture monitoring to aid decision making 64 % shovel or auger 44 % - Consider real-time ETc when making decisions Prefer real-time ETc to historic or normal year averages 60 % know water application rates of irrigation sytems 23 % - Crop stress, pressure chamber and stem water potential 58 % look for and respond to visual signs of crop stress 18

19 Almond guidelines Walnut Guidelines 19

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21 According to a previous study, mild to moderate stress may not be unusual in commercial almond production (Shackel 2001). Therefore, it is difficult to determine how much water might be saved statewide if our recommendations for regulated deficit irrigation were widely adopted. 21

22 Average Seasonal SWP (bars) Seasonal Range in SWP (bars) Average Applied Irrigation Water (inches / acre) -3.6 to to to to to to to to to 23 Location Tehama County CA Three-year Average SWP (bars) 2002 Yield (tons/ac) 2003 Yield (tons/ac) 2004 Yield (tons/ac) 2004 Yield Reduction (%) a 2.82 a 2.24 a a 2.33 b 1.65 b a 2.07 b 1.31 b 42 San Joaquin County CA a 4.43 a 3.77 a a 3.94 a 2.98 b a 3.80 a 3.08 b 18 22

23 Achieving water (energy) conservation with wider adoption of irrigation scheduling tools is questionable Depends on existing irrigation management More water, production, farm revenue, quite possible Representative, automated soil moisture monitoring provides insight to irrigation needs, fate of water and rainfall, and provides detail and ease of acquiring information. Some important, outstanding questions still surround realtime ETc estimates for almonds and walnuts o o In particular, the effect of canopy size on ETc? What is the potential for site specific measurement of ETc? A reliable indicator of tree water status offers unique and important insights to making irrigation decisions o o o Many orchardists know this intuitively and indicate so Labor intensity of the pressure chamber and SWP can be a barrier Perhaps the tool with a greater chance of realizing water savings 23

24 Faculty, CE Specialists, Staff Farm Advisors Michael Delwich David Goldhamer Blaine Hanson Bruce Lampinen Sam Metcalf Terry Prichard Larry Schwankl Ken Shackel Richard Snyder Dave Smart Shrini Upadhyaya Mike Whiting Others Robert Beede Richard Buchner Joe Connell David Doll Allan Fulton Joe Grant Janine Hasey Bill Krueger Dan Munk Franz Neiderholzer Blake Sanden Others THANK YOU! 24