Nitrogen and Potassium Utilization in Almond Orchards
F.J.A. NiederholzerUC ANR CE Farm Advisor, Colusa/Sutter/Yuba Counties
February 7th, 2017
This talk will cover the following topics.
Annual N Treatme
nt(N/acre)
2008Kernel yield
(lb/acre)
2009Kernel yield
(lb/acre)
2010Kernel yield
(lb/acre)
2011Kernel yield
(lb/acre)125 lb 3,506 a 2,715 a 2,849 a 3,811 a
200 lb 3,534 a 2,943 ab 3,413 b 4,274 b
275 lb 3,732 a 3,183 b 3,734 bc 4,643 c
350 lb 3,733 a 3,489 b 4,030 c 4,735 c
Why N & K matters in almond production
N & K in the soil and trees
Effective, efficient and safe N & K management
Annual N Treatment(N/acre)
2008Kernel yield
(lb/acre)
2009Kernel yield
(lb/acre)
2010Kernel yield
(lb/acre)
2011Kernel yield
(lb/acre)
125 lb 3,506 a 2,715 a 2,849 a 3,811 a
200 lb 3,534 a 2,943 ab 3,413 b 4,274 b
275 lb 3,732 a 3,183 b 3,734 bc 4,643 c
350 lb 3,733 a 3,489 b 4,030 c 4,735 c
Within a year of changes in N fertilizer treatments, yield differences can appear.
15.3 28.9 30.2ROI
P. Brown, U
C Davis
Nutrient Nutrient removed in 1000 lb kernel crop
Nutrient/acre removed in average crop
Potassium 80.0 lbs 195.2 lbsNitrogen 68.0 lbs 165.9 lbsPhosphorus 8.96 lbs 21.86 lbs
Calcium 6.68 lbs 16.30 lbsMagnesium 4.64 lbs 11.32 lbs
Sulfur 2.62 lbs 6.39 lbsBoron 0.31 lbs 0.76 lbsIron 0.19 lbs 0.46 lbsZinc 1.12 oz 2.72 oz
Manganese 0.68 oz 1.66 ozCopper 0.34 oz 0.83 oz
P. Brown, U
C Davis
Nitrate concentrations in many CA wells exceed drinking water standards
Red dots represent wells that exceed the drinking water standards.
Excessive orchard N risks increasing hull rot and yield loss.
Treatment(K2O/acre/
year)
1998 Kernel yield
(lb/acre)
1999 Kernel yield
(lb/acre)
2000 Kernel yield
(lb/acre)
ROI(income$:
fertK$)
0 lb 780 a 3930 a 2410 a240 lb 890 a 3840 a 2860 b600 lb 830 a 4380 a 2860 b960 lb 1070 a 4020 a 2770 b
Reidel, Weinbaum, Brown and Duncan, UC Davis
Potassium fertilization provides a return on investment, especially after heavy crop year.
6.12.41.2
The NITROGEN CYCLE in soils.
Singer and Munns, Soils: An Introduction. 2002, page 173
Singer and Munns, Soils: An Introduction. 2002, page 229
Potassium Cycle in soil.
Potassium and nitrogen reach roots by two processes: mass flow and diffusion. Generally, N is more soil mobile than K.
Nutrient Root interception Mass Flow Diffusion
Nitrogen 1 99 0
Potassium 2 20 78At the root surface, plants expend energy to absorb the nutrients.
In the tree, potassium is a chemical activator/regulator, while nitrogen is a essential ingredient of proteins, etc.
Nitrogen Potassium
Function
Essentialingredient in molecules in
plant
Helps regulate essential
processes and transport within
the plant Feedback
mechanism limiting uptake?
Yes No (luxury consumption)
The timing of greatest need for available N is March to June, when the crop is growing.
P. Brown, UC Davis
2011 2012
P. Brown, UC Davis
The amount of N (and K) needed during March to June is driven by cropload.
Same orchard. 2012 orchard N use is 200 lbsN/acre LESS than 2011 due to very light ’12 crop.
Almond nut K & N accumulation patterns differ during a growing season.
Lb N per 1000 lb crop Lb K per 1000 lb crop
Days after full bloom Days after full bloom
Nitrogen storage in woody tissue = ̴40 lbs N/acrePotassium storage in woody tissue = ̴25 lbs K/acre
P. Brown, UC Davis
Traditional orchard fertility test (leaf analysis) are a good indication of deficient, but not excessive nutrients.
P. Brown, UC Davis
• Right Rate• Right Time
• Right Location
• Right Material
The 4 R’s of Fertilizer management are the guiding strategy for all nutrients & especially Nitrogen and Potassium.
• Right Rate
•Right Time• Right Location
• Right Material
The 4 R’s of Fertilizer management are the guiding strategy for all nutrients & especially Nitrogen and Potassium.
1. Use yield history to estimate annual budget. Ante up: apply 20% of annual budget by mid-March.
Application Timing % of total budgetLb. N per
application if it’s a normal crop
Bloom-leaf out (Feb-Mar) 20% 47
April 30%
May/June 30%Hull split to postharvest 20%
Experience & spring leaf test results helps decide N & K inputs after first 20% of annual N budget is applied.
In season, use spring leaf levels (N) to revise fertilizer program on the go.
• UC ESP (Early season Protocol) – 43 days (± 6 d.) after full bloom– Take all leaves of 2-3 non-bearing spurs around the tree– Sample trees at least 90’ feet apart– Request full nutrient analysis from lab– Plug results into UC model in Excel.– Find the model at:http://ucanr.edu/sites/scri/Crop_Nutrient_Status_and_Demand__Patrick_Brown/orhttps://www.sustainablealmondgrowing.org/
2. Use experience, bloom weather & spring leaf N levels to decide on April-June rates (30% & 30% of total if all appears “normal”).
Application Timing % of total budget Lb. N per application if it’s a normal crop
Bloom-leaf out (Feb-Mar) 20% 47
April 30% 71May/June 30% 71
Hull split to postharvest
3. Use actual cropload and summer leaf N analysis to determine how much, if any, postharvest N to apply.
Application Timing % of total budget Lb. N per application if it’s a normal crop
Bloom-leaf out (Feb-Mar) 20% 47
April 30% 71May/June 30% 71
Hull split to postharvest 20% 47?
An example of differences in yields and N use in the same orchard. Nickels pruning trial. 2015.
Variety Yield/acre N use/acre*
Nonpareil 2,947 200Monterey 2,586 176
Aldrich 2,468 168Carmel 2,225 151
*Assumes 68 lbs N/1000 lbs crop for all varieties
Irrigation systems can be designed to treat varieties separately.
Potassium timing and rates are similar to nitrogen for the same cropload.
Application Timing % of total budget Lb. K2O per application if it’s a normal crop
Bloom-leaf out (Feb-Mar) 20% 46
April 30% 70June 30% 70
Hull split to postharvest 20% 46
Summer leaf levels are a report card for preharvest fertility & key planning input(s) for postharvest fertility program.
Critical July leaf nutrient concentration (%)
Old target New targetNitrogen 2-2.5 2.4-2.5
Potassium >1.4 1.0
• Right Rate
• Right Time
•Right Location• Right Material
The 4 R’s of Fertilizer management are the guiding strategy for all nutrients & especially Nitrogen and Potassium.
Right Place: Irrigation Rapidly Moves N into SoilSurface applied N Followed by Irrigation (90 minutes)
Broadbent, 1958, graph from www.IPNI.org
In season, use K deficiency leaf symptoms (or early leaf sampling from private lab) to revise fertilizer program on the go.
Soil CEC (soil K storage potential) influences K input plans & practices.
Practice High CEC Soil (>15 meq/100 g of soil)
Low CEC soil (<15 meq/100g of soil)
Dormant Soil Applications Yes – can be “slugged” on Yes – but only partial
budgetBanding gypsum to
move potassium Yes, if heavy clay NOIn-Season
Applications Yes, if needed Yes- 40-60% of the budget
Fertigation of K Yes Yes – be cautious of large applications
No benefit from applying more than 240 lbs K2O/acre/year has been measured in short (< 5 years) UC trials.
Right timing, location, & rate are vital to effective, efficient & safe N & K fertilization. Material is less critical.
Nitrogen PotassiumAnnual Rate* 68 lbs N 80 lbs K
(96 lbs K2O)
Timing Mar-early June; Sept.20-30-30-20 Mar-June; Sept.
Location Tree row, upper 0-2’ root zone
Tree row, upper 0-2’ root zone
Material Grower choice Grower choice
*per 1000 lbs kernel crop (includes hull, shell and kernel). Adjust annual rate for the current year based on cropload and tissue tests
Thank you