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