Strawberry Nitrogen Fertilization from Organic Nutrient Sources

Mark Gaskell, Mark Bolda, Joji Muramoto,and Oleg Daugovish

U i it f C lif i C ti E t iUniversity of California Cooperative Extensionand University of California – Santa Cruz

USA

Background and overview

• Organic or “ecological” production of strawberries is increasing rapidly in the US US

• Prices for organic strawberries ae typically 15-25% higher than for c nv nti n l b rri sconventional berries

• Prices are also more stable – low prices do not reach as low as conventionally do not reach as low as conventionally grown fruit

• Little research-based information il bl t id ni savailable to guide organic growers

CA Strawberry Acreage

Source: K.Klonsky - CDFA registration

CA Organic Strawberry Acreage

Source: K. Klonsky - CDFA registration

CA Organic Strawberry Sales

Source: K. Klonsky - CDFA registration

Nitrogen and organic strawberry production

• Transplanted strawberries in California usually grown as an annual cropplanted October – November and h d lpharvested January >> July- critical N needs in first 2-6 months

• Timing of N availability is critical for Timing of N availability is critical for strawberry yield and fruit quality

• Asynchrony of N availability has been d d f

y y ydocumented for organic N systems.

• Organic N management is inefficient and costlycostly.

Principal California Strawberry Production Districts

35o

N availability affects number

d i fand size of crown shoots.

Crop N demande

Warmer temperatures

n Uptake

Cooler temperatures

Nitrogen

2 763 54 981 10

WeekTransplant

Crop

 

Time

Nitrogen in organic systems

• Multiple studies over many years in diverse cropping environments have shown that preplant applied compost or p p pp pincorporated green manure do not release appreciable N beyond 6-8 weeks

• Synchrony of N supply to strawberries • Synchrony of N supply to strawberries during early development is critical to competitive yields and fruit size.

• Periodic N fertilization – liquid N injection – critical to organic production

30

20

25+ GM

GMpm)

15

20 - GM

3-N

(pp

10

al N

O 3

5

Resi

dua

0

May Jun

Jun Jun Jul Jul Aug

R

19-M

ay2-J

un16

-Jun

30-Ju

n14

-Ju28

-Ju11

-Aug

Date

Pre‐plant organicke p gmaterialmineralization

gen Uptak

and Nitrog

0 2   763 54 981   10ralization a

76  3   54   9  8   10

Prepare beds. apply plastic

WeekCompost incorporation

of N M

iner

plastic,drip tape arrival of plants from nursery 

Rate o

Time

Pre‐plant organicke

C N d d

p gmaterialmineralization

gen Uptak

Southern Districts

Northern

Crop N demand

and Nitrog

0 2   763 54 981   10

Northern DIstricts

ralization a

76  3   54   9  8   10

Prepare beds. apply plastic

WeekCompost incorporation

of N M

iner

plastic,drip tape arrival of plants from nursery 

Rate o

Time

Liquid fertilizers are valuable d t l b t thand necessary tools but they

have special challenges for efficient management:

• If material not finely ground N is lost behind filter or drip emitter.

C ti i i i d• Continuous mixing required

• Mineralization characteristics are important

90

100180 lb N / acreWhen does N

il bl ?

70

80

Residual

come available?

50

60

l Soil Nitr

30

40

rate-N (pp

14 3 5 0

10

20

pm)

May

5 7 9

11 13 15 CoPell

FishPhyta

LiqFisFeatheGranGu

0

Date / Week CompostellChickhmeal

ytaminish er

Guano

= N applied

Pre‐plant organicke

C N d d

p gmaterialmineralization

gen Uptak

Southern Districts

Northern

Crop N demand

and Nitrog

0 2   763 54 981   10

Northern DIstricts

ralization a

. . ..76  3   54   9  8   10

Week

of N M

iner

Rate o Will need periodic (weekly(?)

organic N injection

Time

Organic fertilizer problem areas

• lack uniformity • bulky• bulky,• unstable, • inconsistency --> hidden y

management costs • higher cost and variability for

research research

Certified Organic Fertilizers

Field trials evaluate efficacy of alternative fertilizer o a te at e e t ematerials

Strawberry Nitrogen Fertilization fromOrganic Nutrient SourcesOrganic Nutrient Sources

Mark Gaskell, Mark Bolda, Joji Muramoto,and Oleg Daugovishand Oleg Daugovish

University of California Cooperative Extensionand University of California – Santa Cruzand University of California Santa Cruz

USA