Publication 360, Fruit Production Recommendations:
Chapter 5: Berry Crops - Blueberry Nutrition


Excerpt from Publication 360, Fruit Production Recommendations 2010-11,
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Cover of Publication 360, Fruit Production RecommendationsTable of Contents

  1. Highbush Blueberries
  2. Other berry nutrition information
  3. Pub 360 Chapter 5, Berry Crops - (PDF 364 kb)
  4. Related Links

Highbush Blueberries

Introduction

Blueberries perform best on acidic, well-drained soils with high organic matter content.

  • Before you plant, test to determine the pH of the soil and fertilizer requirements.
  • Incorporate acidic peat moss with the soil in the planting hole to significantly improve plant establishment and development. Dry peat moss will draw soil moisture away from plant roots so be sure it is thoroughly moistened before planting.
  • For information on increasing soil organic matter, see Soil Management at ontario.ca/crops.

pH requirements

Blueberries require a soil pH between 4.2 and 5.0 for optimum growth and production. A soil pH above 6.5 usually cannot be lowered economically through the use of sulphur or peat moss. For this reason, choose the site for blueberry production carefully.

  • If the soil pH is too high but less than 6.5, acidify through the incorporation of elemental sulphur and/or acidic peat moss prior to planting. See Table 5-1. Amount of Sulphur Required to Lower Soil pH. This also provides essential organic matter.
  • Incorporate sulphur one year prior to planting to allow sufficient time for the sulphur to acidify the soil.
  • Check the soil pH annually in the plant row and add sulphur when necessary.

Fertilizer for blueberries

Nitrogen (N)

Highbush blueberries respond best to ammonium forms of nitrogen. Use ammonium sulphate (21% N) if the soil pH is above 5.0 and urea (46% N) if the pH is below 5.0. Avoid the use of the nitrate form of nitrogen. Avoid fertilizers containing lime filler as they will raise the pH of the soil.

  • In the spring after planting, apply a total of 12 g of actual nitrogen per bush in a split application. Increase the rate of nitrogen each year until a total of 36-48 g per bush is applied. Apply the nitrogen just prior to bud break, petal fall and early July.
  • Distribute the fertilizer in a circle from 30 cm around the plant to just beyond the spread of the branches. On older bushes, apply most of the fertilizer under the outer spread of the branches. See Table 5-2. Nitrogen Requirements for Highbush Blueberries, on this page.

Table 5-1. Amount of Sulphur Required to Lower Soil pH (kg/ha) (PDF 68 kb)

Soil type
For each 1.0 pH unit
For each 0.1 pH unit
sand
350
35
sandy loam
750
75
loam
1,100
110

Example: The initial pH of a sandy loam soil is 6.2; the desired soil pH for blueberries is 4.8. The soil pH must be lowered by 6.2-4.8 = 1.4 units. Therefore, 1.4 ? 750 = 1,050 kg/ha of sulphur is required.

Table 5-2. Nitrogen Requirements for Highbush Blueberries (g N per plant) (PDF 65 kb)

Plant Age
April 1-15
May 15
July 1
Newly set
0
6
6
1 year
3
6
6
2 year
6
6-12
6-12
3 year
9
6-12
6-12
4 year
12
12-18
6-12
5 year
15
12-18
6-12
6 year or older
18
12-18
6-12

 

Phosphorus (P) and Potassium (K)

Apply phosphorus and potassium according to soil tests. Consult Table 5-3. Phosphorus and Potassium Requirements for Highbush Blueberries, Strawberries, Raspberries, Currants, Gooseberries for soil test interpretation. A single application of phosphorus at soil preparation time is usually all that is required. It is critical to correct phosphorus deficiencies prior to planting.

Apply all of the required potassium early in the spring under the outer branches of the bushes as described for nitrogen. Potassium can be mixed and applied with the spring nitrogen. Use sulphate of potash magnesia (22% potash, 11% magnesium) or potassium sulphate (50% potash). Blueberries are sensitive to injury from the chloride contained in muriate of potash (0-0-60).

Table 5-3a. Phosphorus Requirements for Highbush Blueberries, Strawberries, Raspberries, Currants, Gooseberries (PDF 74 kb)

Soil test
(ppm P)

Rating
New Planting
Phosphate required
(kg P2O5 per ha)
Established plantings
Phosphate required
(kg P2O5 per ha)
0-3
HR
140
100
4-5
HR
130
90
6-7
HR
120
80
8-9
HR
110
70
10-12
HR
100
70
13-15
HR
90
60
16-20
MR
70
50
21-25
MR
60
40
26-30
MR
50
30
31-40
MR
40
20
Above 40
MR
0
0

HR, MR, LR, denote, respectively, high, medium, AND low probabilities of profitable crop response to applied nutrient.


Table 5-3b. Potassium Requirements for Highbush Blueberries, Strawberries, Raspberries, Currants, Gooseberries (PDF 74 kb)

Soil test (ppm K)
Rating
Potash required (kg K2O per ha)
0-15
HR
130
16-30
HR
120
31-45
HR
110
46-60
HR
110
61-80
HR
90
81-100
HR
80
101-120
MR
70
121-150
MR
60
151-180
MR
40
Above 180
MR
0

HR, MR, LR, denote, respectively, high, medium, AND low probabilities of profitable crop response to applied nutrient.

Other nutrient requirements

Magnesium (Mg) deficiency may occur on blueberries. Soil and/or foliar applications of magnesium are required to correct this deficiency. For soil applications, 80 kg Mg per ha is required where a confirmed deficiency exists. Use magnesium sulphate (Epsom salts, 9.5% Mg) or sulphate of potash magnesia (21% potash, 11% Mg). Since sulphate of potash magnesia contains potash, adjust the rate of application to coincide with potash requirements. For foliar sprays, 1.9 kg Mg per 1,000 L of water (20 kg magnesium sulphate, Epsom salts) with at least 2,000 L/ha should correct the deficiency. Annual foliar sprays may be necessary.

Leaf analysis

Leaf tissue analysis can help to assess the nutrient status of the plants and more accurately determine fertilizer requirements. In late July, take leaf samples from halfway down the new shoot growth of the current season. For adequate representation, collect at least 100 leaves throughout the sampling area. Sample areas with different soil, plant vigour, fertility programs, etc., separately. See Table 5-4. Standard Ranges for Nutrient Levels in Highbush Blueberry Leaves.

Table 5-4. Standard Ranges for Nutrient Levels in Highbush Blueberry Leaves (PDF 72 kb)

Element ( )
Acceptable Range
Nitrogen (N)
1.7-2.3%
Phosphorus (P)
0.15-0.40%
Potassium (K)
0.36-0.7%
Calcium (Ca)
0.3-0.8%
Magnesium (Mg)
0.12-0.3%
Manganese (Mn)
150-500 ppm
Iron (Fe)
30-100 ppm
Zinc (Zn)
10-100 ppm
Boron (B)
15-50 ppm

See Appendix C, Accredited Soil-Testing Laboratories in Ontario, for a list of laboratories that provide leaf analysis.

Micronutrients for Berry Crops

Deficiencies of micronutrients or trace elements are not widespread in Ontario fruit plantings. The desirable range for micronutrients is quite narrow. More damage is possible if micronutrients are applied in excess rather than from deficiencies. For this reason, do not apply micronutrients to fruit crops unless leaf analysis or visible symptoms confirm a deficiency. Apply only the deficient nutrient in sufficient quantities to correct the problem. Leaf analysis is more effective than soil analysis to evaluate a crop's micronutrient status.

See Micronutrients, for additional information.

Related Links

 


For more information:
Toll Free: 1-877-424-1300
Local: (519) 826-4047
E-mail: ag.info.omafra@ontario.ca
Author: OMAFRA Staff
Creation Date: 27 January 2010
Last Reviewed: 04 December 2010