walnut nutrition management: where, when & how …cecontracosta.ucanr.edu/files/209257.pdf ·...
TRANSCRIPT
Walnut Nutrition Management:
Where, When & How (Much?)
Katherine Pope
UCCE Sac-Solano-YoloMarch 11, 2015
Overview
• Principles of N Management
• N Budget Worksheet
• Areas for Improved Efficiency
Take Aways
1) 30 – 44 lbs N / ton
harvested nuts
2) Demand steady over
growing season
3) Roots in top 2-3 feet
Why Care?
Ag 94% groundwater N
30+% of wells
over EPA limits
94% from Crops
Images: Harter et al, 2012
4 R’s of N Management
• Apply the RIGHT RATE
• Apply at the RIGHT TIME
• Apply in the RIGHT PLACE
• Using the RIGHT SOURCE
4 R’s of N Management
• Apply the RIGHT RATE – How Much
• Apply at the RIGHT TIME - When
• Apply in the RIGHT PLACE - Where
• Using the RIGHT SOURCE
Methods – NPK Demand Model
Apr– Nov
May – Sept/OctSenescence
Jan, Apr, May, Jul, Nov
3 x Chandler, Tulare 10 trees / site
4 R’s of N Management
• Apply the RIGHT RATE
• Match SUPPLY w/ tree DEMAND
• Fertilizer + organic N + water
Nutrients in Fruit - Totals
N (lbs/ton) - 2013
Site Nuts Hulls
N Chandler 25.86 a 0.66
D Chandler 30.90 a 0.52
S Chandler 24.62 a 0.68
N Tulare 24.82 b 0.75
D Tulare 31.82 a 1.29
S Tulare 26.94 b 1.91
N / ton of nuts (in-shell, 8% moist) and assoc. hulls.
*Letters show dif’s w/in cv.
Meat & Shell: 25-32 lbs
Hulls: 0.5-2 lbs
Other Scraps: 0.5-2 lbs
New Growth: 4-8 lbs
=
30-44 lbs N / ton in-shell
4 R’s of N Management
• Apply at the RIGHT TIME
• Match w/ timing of tree demand,
root uptake
• Trees take up nutrients when
needed, not when applied
Nitrogen in Fruit - Monthly
0
5
10
15
20
25
30
May Jun Jul Aug Sep
N (
Lbs
/ To
n In
-Sh
ell H
arve
sted
)
Chandler - N - 2013
PreviousIn-Month
0
5
10
15
20
25
30
May Jun Jul Aug Sep
N (
Lbs
/ To
n In
-Sh
ell H
arve
sted
)
Tulare - N - 2013
24%
24%
28%
24%
20%
29%
19%
14%
18%
N accumulation in fruit fairly evenly distributed over the course of the
growing season for both cultivars
N Content of Perennial Parts
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 2 4 6 8 10 12
% N
Month
SmlRt
LrgRt
Branc
Canop
Scaff
Trunk
*
*
Nitrogen in Fruit - Monthly
0
5
10
15
20
25
30
May Jun Jul Aug Sep
N (
Lbs
/ To
n In
-Sh
ell H
arve
sted
)
Chandler - N - 2013
PreviousIn-Month
0
5
10
15
20
25
30
May Jun Jul Aug Sep
N (
Lbs
/ To
n In
-Sh
ell H
arve
sted
)
Tulare - N - 2013
24%
24%
28%
24%
20%
29%
19%
14%
18%
N accumulation in fruit fairly evenly distributed over the course of the
growing season for both cultivars
4 R’s of N Management
• Apply in the RIGHT PLACE
• Delivery to active roots
• N moves w/ water
• Minimize movement below
root zone
Courtesy www.IPNI.orgLampinen et al
Surface N + 90 min irrig’t
Roots in top 30”
N moves 6-9”
in 90 min
Show worksheet
Nutrients
Kathy Kelley-Anderson et al: ANR Pub # 21623
Supply = Demand
Loss
Show worksheet
Show worksheetDEMAND
Show worksheetDEMAND
(supply)
(supply)
(supply)
Show worksheetDEMAND
(supply)
(supply)
(supply)
NonFert N Supply
Show worksheetDEMAND
(supply)
(supply)
(supply)
NonFert N Supply
NonFertDemand - =Tree Needs
Show worksheetDEMAND
(supply)
(supply)
(supply)
NonFert N Supply
NonFertDemand - =Tree Needs
Need / =Effic.
Amt of
Fertilizer to
Apply
Hypothetical
• Jonny Walnut Grower
– Yield: 3 tons / ac / year
– Groundwater: 12 ppm Nitrate
– No Compost or Cover Crop
– 100 lbs N demand
1. Nitrogen removed in crop
3 120
2. Nitrogen from
irrigation water
12 429
20
0
20
0
20
6. Additional nitrogen
needed
6. Additional nitrogen
needed
3 120
20
100
7. Nitrogen fertilizer
application rate
100
100 0.4 250
7. Nitrogen fertilizer
application rate
100
100 0.7 143
70 0.7 143
Right Time
Right Place
4 R’s of N Management
Right Rate
4 R’s of N Management
• Apply at the RIGHT TIME
• Match w/ timing of tree demand,
root uptake
• Trees take up nutrients when
needed, not when applied
Nitrogen in Fruit - Monthly
0
5
10
15
20
25
30
May Jun Jul Aug Sep
N (
Lbs
/ To
n In
-Sh
ell H
arve
sted
)
Chandler - N - 2013
PreviousIn-Month
0
5
10
15
20
25
30
May Jun Jul Aug Sep
N (
Lbs
/ To
n In
-Sh
ell H
arve
sted
)
Tulare - N - 2013
24%
24%
28%
24%
20%
29%
19%
14%
18%
N accumulation in fruit fairly evenly distributed over the course of the
growing season for both cultivars
4 R’s of N Management
• Apply in the RIGHT PLACE
• Delivery to active roots
• N moves w/ water
• Minimize movement below
root zone
Courtesy www.IPNI.orgLampinen et al
Surface N + 90 min irrig’t
Roots in top 30”
N moves 6-9”
in 90 min
5th R – Leaf MonitoRing
• Monitor impact of changing practices
• Deficiencies affect crop before leaves
• Protocol:
• Sample in July
• Only terminal leaflets
• 6-8 ft from ground, tree periphery
• ~50 leaflets from area of interest,
scattered
Take Aways
1) 30 – 44 lbs N / ton
harvested nuts
2) Demand steady over
growing season
3) Roots in top 2-3 feet
Resources• Sac Valley Water Coalition – svwqc.org
• Walnut Production Manual, ANR 3373
• Guide to Efficient Nitrogen Fertilizer Use in Walnut Orchards, ANR 21623
• Fruit & Nut Research and Information Center (FNRIC) fruitsandnuts.ucdavis.edu
• Patrick Brown, Ted DeJong, Sebastian Saa, Andres Olivos, Kathy Kelley, Joe Grant, Janine Hasey
• Funding: CWB, CDFA
Contributors
http://www.waterboards.ca.gov/centralvalley/water_issues/irrigated_lands/coalition_groups/
www.svwqc.org/sacramento-valley-watersheds/