Nitrogen and Potassium Utilization in Almond Orchards F.J.A. Niederholzer UC ANR CE Farm Advisor, Colusa/Sutter/Yuba Counties February 7 th, 2017
This talk will cover the following topics. Annual N Treatme nt (N/acre) 2008 Kernel yield (lb/acre) 2009 Kernel yield (lb/acre) 2010 Kernel yield (lb/acre) 2011 Kernel 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 Effective, efficient and safe N & K management N & K in the soil and trees
Within a year of changes in N fertilizer treatments, yield differences can appear. Annual N Treatment (N/acre) 2008 Kernel yield (lb/acre) 2009 Kernel yield (lb/acre) 2010 Kernel yield (lb/acre) 2011 Kernel 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 ROI 15.3 28.9 30.2 P. Brown, UC Davis
Nutrient Nutrient removed in 1000 lb kernel crop Nutrient/acre removed in average crop Potassium 80.0 lbs 195.2 lbs Nitrogen 68.0 lbs 165.9 lbs Phosphorus 8.96 lbs 21.86 lbs Calcium 6.68 lbs 16.30 lbs Magnesium 4.64 lbs 11.32 lbs Sulfur 2.62 lbs 6.39 lbs Boron 0.31 lbs 0.76 lbs Iron 0.19 lbs 0.46 lbs Zinc 1.12 oz 2.72 oz Manganese 0.68 oz 1.66 oz Copper 0.34 oz 0.83 oz P. Brown, UC 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.
Potassium fertilization provides a return on investment, especially after heavy crop year. Treatment (K 2 O/acre/ year) 1998 Kernel yield (lb/acre) 1999 Kernel yield (lb/acre) 2000 Kernel yield (lb/acre) 0 lb 780 a 3930 a 2410 a ROI (income$: fertk$) 240 lb 890 a 3840 a 2860 b 600 lb 830 a 4380 a 2860 b 960 lb 1070 a 4020 a 2770 b 6.1 2.4 1.2 Reidel, Weinbaum, Brown and Duncan, UC Davis
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 78 At 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. Function Feedback mechanism limiting uptake? Nitrogen Essential ingredient in molecules in plant Yes Potassium Helps regulate essential processes and transport within the plant No (luxury consumption)
The timing of greatest need for available N is March to June, when the crop is growing. P. Brown, UC Davis
The amount of N (and K) needed during March to June is driven by cropload. 2011 2012 Same orchard. 2012 orchard N use is 200 lbs N/acre LESS than 2011 due to very light 12 crop. P. Brown, UC Davis
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/acre Potassium 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
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. Right Rate Right Time Right Location Right Material
1. Use yield history to estimate annual budget. Ante up: apply 20% of annual budget by mid-march. Application Timing % of total budget Lb. 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_d emand Patrick_Brown/ or https://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% 71 May/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% 71 May/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 2,947 200 Monterey 2,586 176 Aldrich 2,468 168 Carmel 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. K 2 O per application if it s a normal crop Bloom-leaf out (Feb-Mar) 20% 46 April 30% 70 June 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 target Nitrogen 2-2.5 2.4-2.5 Potassium >1.4 1.0
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
Right Place: Irrigation Rapidly Moves N into Soil Surface 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 Dormant Soil Applications Banding gypsum to move potassium In-Season Applications Fertigation of K High CEC Soil (>15 meq/100 g of soil) Yes can be slugged on Yes, if heavy clay Yes, if needed Yes Low CEC soil (<15 meq/100g of soil) Yes but only partial budget NO Yes- 40-60% of the budget 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 Potassium Annual Rate* Timing Location 68 lbs N Mar-early June; Sept. 20-30-30-20 Tree row, upper 0-2 root zone 80 lbs K (96 lbs K 2 O) Mar-June; Sept. 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