Placement of additional drip lines to enhance soil fumigation and

irrigation efficiency and minimize environmental impacts

Oleg Daugovish, Ben Faber, Surendra Dara, Mike Cahn, Steve Koike and Husein Ajwa (Univ. of California

Cooperative Extension farm advisors and specialist)

Collaborators:

• Dole (Watsonville), Manzanita Berry Farms (Santa Maria), and Ito Bros. (Oxnard), and Solimar Farms (Camarillo)

• California Strawberry Commission

• Farm Bureau, Resource Conservation Districts, Natural Resource Conservation Service, United Water and other stakeholders

California strawberries

• $ 2.6 billion annual value in California (~90% of US)• #6 crop in California• Neighbors: urban and natural environments

Two problems: lack of water and soil pathogens

Macrophominaphaseolina

Fusarium oxysporum

Using drought tolerant plants

Taking

shower with friends

Harvesting rainwater

From United Water CD report:

Water Pumping through pipeline, Ventura County, CA

Why are sprinklers used instead of drip?

Used for other purposes: wet

soil before bed shaping,

‘settling furrows and beds’,

frost protection, fast plant

hydration during hot wind

conditions

Used for fumigation and

fertigation only

Water delivered into

planting holes from the top

aids in leaching salts

Water delivered at drip

burial depth, salts above

drip not leached

Immediate plant-water

contact aids secondary

root development

Risk of plants ‘drying out’

SPRINKLERS DRIP

Placement of drip: Deliver water to roots and move salts away

VS

X XX

X X X

6 in

12 in

F. oxysporum inoculum buried in beds prior to fumigation

Drip lines

Effect of location on F. oxysporum survivalS

pore

s p

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m o

f soil

Beds fumigated with 200 lbs/a PicClor-60

6” depth

12” depth

2013-14 NSSI project

Oxnard and Camarillo

Santa Maria

Watsonville

Drip Fumigation

• Camarillo (200 lbs /A InLine): native Fusarium oxysporum in soil: no symptoms in plants observed as of May 15

• Watsonville (300 lbs /A Piclor 60): buried inoculum – no survivorship in 2 or 4 lines per bed at 2 depth for both M. phaseolina and F. oxysporum

• Oxnard: did not fumigate with 4 lines but irrigated with 4 or 3 in season

Oxnard: irrigation affecting plant mortality due to F. oxysporum

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Surface 4 drips-only

Buried 4 drips- only

Sprinkler, then 3 drips

Oxnard, CA, Oct 28, 2014

What was % of plant establishment?98.45 surface drip, 98.6 buried drip and 98.3% in sprinkler irrigation

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21-Oct 28-Oct 4-Nov 11-Nov 18-Nov 25-Nov 2-Dec 9-Dec 16-Dec 23-Dec 30-Dec 6-Jan 13-Jan 20-Jan 27-Jan 3-Feb

EC in root zone, bulk soil

sprinkler, then 3 tapes

4 tapes surface or buried

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0.050 m³/m³

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21-Oct 28-Oct 4-Nov 11-Nov 18-Nov 25-Nov 2-Dec 9-Dec 16-Dec 23-Dec 30-Dec 6-Jan 13-Jan 20-Jan 27-Jan 3-Feb

Volumetric moisture in root zone

avg buried drip

avg surface drip

avg overhead

Establishment period

4 drip surface 4 drip buried Sprinkler, then 3 drip

chloride 0.64 meq/L 0.79 meq/L 2.74 meq/L

sodium 5.89 meq/L 7.09 meq/L 9.97 meq/L

EC sat

paste

3.66 dS/m 4.21 dS/m 3.99 dS/m

sulfate 39.2 meq/L 36.3 meq/L 45.2 meq/L

4 drip surface 4 drip buried Sprinkler, then 3 drip

Nitrate -N 931 ppm 668 ppm 905 ppm

Phosphate -P 2030 ppm 2040 ppm 2450 ppm

Zinc 21.9 ppm 24.1ppm 27.7 ppm

Manganese 76 ppm 109 ppm 174 ppm

Soil Analyses 0-6 “ Nov 19

No differences in Ca, Mg, K or B, slightly heavier soil in sprinkler block

No differences in Ca, Mg, K, Fe, or Na slightly heavier soil in sprinkler block

Plant Tissue Analyses, Feb 18

Buried 4 lines = SprinklerSurface 4 lines(22% smaller)

Nov 26, 2014 canopy size

Plant dry biomass, Dec 12

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Dry biomass of old crowns

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Marketable fruit yield- Oxnard

Surface 4 drips-only

Buried 4 drips- only

Sprinkler, then 3 drips

total by Apr 19,622

10,548

8,696

Water use/acre by Nov 12 (before removal of sprinklers):

• 4-DRIP block: 11, 200 gal (by drip) + 4, 060 gal (2 sprinkler runs during Santa Ana conditions, 1st week of Nov) = 15,260 gal

• SPRINKLER block: 47, 250 gal (collected by cans)

Sprinklers for cooling plants

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minutes after end of overhead irrigation

Temperature

Air Leaf

End of sprinkler irrigation

Santa Maria and Watsonville

• 20-30% water savings (reduced sprinkler + 4 drips vs standard sprinkler)

• Similar among treatments: plant performance, soil water and salt parameters

Outreach so far:

• 3 field days (14 speakers) and 2 meetings (380 participants),

• >30 individual contacts with growers and industry stakeholders

• Electronic: web site and blog >6000 hits/month

• Ventura County Star: 2 publications, reached >0.5 mlnpeople (paper and on-line)

• Video on UCCE –Ventura web site (loaded May 25th)

• Doubling number of tapes included in UC water quality BMP guidelines publication (bi-lingual)

Prácticas Agrícolas para Proteger la Calidad del Agua

Grower responses:

• “improved fumigant distribution/wetting pattern in 4-drip beds” (Solimar Farms)

• “next year plan is to increase area with 4-drip use for establishment at least 10 times” (Ito Bros.)

• Dole: “doubling drip tape is becoming increasingly common in Central Coast” and “will help South Coats grower with salts management”

• Manzanita Berry Farms: “ 4 tapes and reduced sprinkler use” is a standard.

• Driscoll’s: Additional drip tapes and micro-sprinkler used for grower demonstrations to save water and minimize runoff (first time in summer strawberry)