Beetroot fertilizer requirements can be calculated if you know your soil type and have a good idea of the yield potential of your land and climate. These are basic norms and your specific microclimate and variety can have an influence on the total amount applied. These norms do not take top dressings into account, only the total amount of N, P and K applied during the growth season. The fertilizer can be applied either through the irrigation system or as granular fertilizer. Consult your supplier on the effectiveness of these fertilizers on the various soils to make adjustments to these amounts.

Three soils are used in these tables:

  • S/SL – Sandy to Sandy Loam
  • SL/S – Sandy Loam to Sand
  • SCL/C – Sandy Clay Loam to Clay

Beetroot Nitrogen (N) application

Beetroot fertilizer requirement ito nitrogen is easy. You don’t need a soil analysis just a good idea of your yield potential in the area. Be careful not to overestimate your potential yields as too much nitrogen will also have a negative effect on total yield and the quality of the bulbs. High nitrogen content makes the plant more susceptible to insect damage and diseases.

Yield target t/ha S/SL SL/S SCL/C
0-40 80-100 70-90 60-80
41-60 100-120 90-110 80-100
61-99 120-140 110-130 100-120

Beetroot Phosphorus (P) requirement – (Bray 1)

Phosphorus fertilizer requirements are based on Bray 1 lab analysis. If another method is used the values must be adjusted. The minimum amount applied is always about 20 kg P per hectare as P is not that mobile and a certain level of P must always be maintained in the soil.

 

P analysis (ppm) Yield target 0-99 t/ha
1-10 140-160
11-20 120-140
21-30 100-120
31-40 80-100
 41-60 60-80
 61-80 40-60
 81-100 20-40
 101-120 0-20
121-200 0

Beetroot Potassium (K) fertilization

Potassium requirements are based on a soil analysis and yield estimates. Potassium is extremely important for flower formation and water regulation. Over fertilization can increase the salt content of the soil to such an extent that water uptake is reduced. Note that low nitrogen soil content will impair the translocation of potassium to other parts of the plant. A potassium deficiency in the plant will not be noticed as quickly as nitrogen or iron. Deficiency symptoms occur first in the older leaves as potassium is transferred to younger leaves first. Note that beans are sensitive to salt stress, so too high applications can reduce yields.

Soil type Soil analysis Yield t/ha
ppm 0-40 41-60 61-99
S/LS 1-20 200 240 290
SL/L 1-30 200 240 290
SCL/C 1-40 200 240 290
S/LS 21-40 162 206 255
SL/L 31-60 162 206 255
SCL/C 41-80 162 206 255
S/LS 41-60 125 172 220
SL/L 61-90 125 172 220
SCL/C 81-120 125 172 220
S/LS 61-80 87 138 177
SL/L 91-120 87 138 177
SCL/C 121-160 87 138 177
S/LS 81-100 56 104 145
SL/L 121-150 56 104 145
SCL/C 161-200 56 104 145
S/LS 101-121 39 70 110
SL/L 151-180 39 70 110
SCL/C 201-240 39 70 110
S/LS 121+ 20 45 70
SL/L 180+ 20 45 70
SCL/C 241+ 20 45 70

 

Below is the well known soil texture triangle on which the Beetroot fertilizer recommendations are based. Most commercial agricultural soils are found in the left bottom corner as they are the most productive and provide the plant with best yield potentials.

Soil textural triangle for Beetroot fertilizer requirements.1)https://commons.wikimedia.org/wiki/File:USDA_Soil_Texture.svg by Christopher Aragón

 

 

References

References
↑1 https://commons.wikimedia.org/wiki/File:USDA_Soil_Texture.svg by Christopher Aragón