Fertilizing Young Almond Orchards

27 Pages·2015·1 MB·English

by  David Doll

Fertilizing Young Almond Orchards
David Doll
UCCE Merced
1/16/2015
Fertilizing Young Almond Orchards
Fertilizing Considerations:
• What type of fertilizer to
apply?
• How much should be
applied?
• How much should be
applied in a single
application?
• What are the other concerns
for young orchards?
Fertilizing Young Almond Orchards –
What Type?
Fertilizer Source Trials
• Two locations within
Merced Co.
• Nitrogen was sourced as
ammonium, nitrate, or
blends
• Applied as granular multiple
times through the year at
the same rate (4 ozs/tree)
• Measured growth, tissue
analysis
First Year Fertilizer Studies:
Merced County
Loamy sand soil, irrigated with solid set sprinklers, neutral soils, low cation
exchange capacity – 4 ozs total N, 6 applications of 1 oz/tree
A
30
AB AB
B
25
)
m
m
20
(

h
t
w
o
15
r
G

l
a
n
o 10
s
a
e
S
5
0
Ammonium Sulfate Calcium Nitrate Slow Release Triple 15
First Year Fertilizer Studies:
Merced County
Sandy loam soil, irrigated with micro-sprinklers, acidic soils, medium cation
exchange capacity – 4 ozs total N, 6 applications of 1 oz/tree
30
25
)
m
m
( 20

h
t
w
o 15
r
G

l
a
n 10
o
s
a
e
S 5
0
Ammonium Calcium Ca/Pot Potassium Slow release Triple 15
sulfate nitrate Nitrate Blend Nitrate
First Year Fertilizer Studies:
Merced County
4
e 3.5
u A A Major nutrients affected
A A
s B BC
s 3
i B
T C by fertilizer content
f
a 2.5 A
e
L
f 2 B
o B B

e
g 1.5
a
t
n
e 1
c
r
e 0.5
P
Treatments not connected by
0
same letter indicate statistical
Nitrogen Phosphorus Potassium Calcium
difference at p>0.05
80
)
M
70
P
P
(
60
n
o
i
Micro nutrients affected t 50
a
r A A Ammonium sulfate
t A
n 40 BC B
by fertilizers – suspect e C A Calcium nitrate
c
n
30
o
changes in soil pH C A B Slow release

e 20
u BC B
s C Triple 15
s 10
i
T

f
a 0
e
L
Zinc Boron Manganese
Fertilizing Young Almond Orchards:
What type?
Nitrogen is nitrogen
- certain fertilizers leach more rapidly
-affect soil pH, changes micronutrient
availability
Fertilizing Young Almond Orchards:
What Rate?
Fertilizer Rate Trials
• Sand soil
• Nitrogen was sourced using
blended triple 15 granular,
controlled release
• Applied at variable rates
with 0, 1, 2, 4, 6 ozs of
N/tree with split
applications
• Tree growth and tissue
(tissue not shown)
Merced Trials – First Year Almond
Fertilization Rate
45
40
)
m
m
35
(

r
e
t 30
e
m
a
25
i
D

k
n 20 Conventional
u
r
T
15
n
i

e
120 Day Controlled
g 10
n
a Release
h
C 5
0
00 1 10 2 20 3 340 5 40 6 50
OuncPeosu nodfs N oift Nroitgroegne/nT/rAecere
Fertilizing Young Almond Orchards:
What rate?
• Study suggest somewhere between 3-4 ozs of
Nitrogen per tree
– Supported earlier work of John Edstrom
– Supports Patrick Brown’s work of 20-30 lbs/acre of
vegetative growth requirement
Rate/Tree 18’x22’ (110) 16’x22’ (123) 14’x22’ (141)
3 oz 20 lbs N 23 lbs N 27 lbs N
4 oz 28 lbs N 31 lbs N 35 lbs N