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Survey and Estimation of NPK (Nitrogen, Phosphorus, Potassium) Absorption (g/m²) by Growth Stage for Cabbage
Overview
Cabbage (Brassica oleracea var. capitata) is a major leafy vegetable widely grown in Japan; fertilizer management (especially NPK) directly affects yield and quality. This report details NPK absorption (g/m²) at each growth stage (germination/seedling, vegetative growth, heading, flowering, maturation/harvest) using domestic and international literature, with estimation methods where direct data are lacking.
1. Total NPK Absorption (Japan Data)
According to agricultural experiment stations, municipalities, and extension materials in Japan, typical total uptake per 10a is:
- Nitrogen (N): 20–30 kg/10a (2.0–3.0 g/m²)
- Phosphorus (P): 5–7 kg/10a (0.5–0.7 g/m²)
- Potassium (K): 25–35 kg/10a (2.5–3.5 g/m²)
Peak uptake consistently occurs around heading initiation. Guidance clearly links fertilization timing to growth stage: low uptake in germination/early seedling, sharp increase in mid-season (vegetative to heading start), slowdown at maturity/harvest, with nutrient redistribution from old leaves to the head in some cases [1][2][3][4][5][6].
2. Absorption Patterns by Growth Stage
Absorption patterns per stage (common in Japanese and international literature):
- Germination/Seedling
Very low NPK uptake; about 2–5% of total. - Vegetative Growth (rosette)
Uptake increases; N and K demand rises. About 15–25% of total. - Heading Initiation
Uptake rate maximizes; 50–60% of total uptake occurs in this period. - Heading / Head Development
High uptake rate but gradually peaks out; P and K uptake continues somewhat. - Flowering / Maturity / Harvest
Little new uptake; redistribution from old leaves. A few percent of total.
This curve matches Japanese reports and California peer-reviewed literature [7] and international extension materials [8].
3. Japan-Specific Data and Limitations
No primary Japanese data directly state stage-by-stage NPK absorption in g/m². Literature mainly reports total uptake (kg/10a or kg/ha) and peak uptake timing. Therefore, allocating Japanese total uptake using international absorption curves (e.g., California research) is a reasonable estimation approach [1–6][7][8].
4. Estimation Method: Stage-by-Stage NPK Absorption
4.1 Basis for Estimation
- Use Japanese total uptake as baseline (e.g., N = 3.0 g/m², P = 0.7 g/m², K = 3.0 g/m²).
- Apply stage absorption rates from California peer-reviewed research [7] and international patterns [8].
- Allocation by stage [7][8]:
| Stage | Absorption share (%) | Absorption (g/m², N example) |
|---|---|---|
| Germination/seedling | 3% | 0.09 |
| Vegetative growth | 20% | 0.60 |
| Heading initiation | 55% | 1.65 |
| Heading–flowering | 17% | 0.51 |
| Maturity/harvest | 5% | 0.15 |
| Total | 100% | 3.0 |
Similar proportions apply to P and K.
4.2 Full N, P, K Example
Using total uptake from [2][3][4]:
- N: 3.0 g/m²
- P: 0.7 g/m²
- K: 3.0 g/m²
Estimated stage absorption (g/m²):
| Stage | N | P | K |
|---|---|---|---|
| Germination/seedling | 0.09 | 0.021 | 0.09 |
| Vegetative growth | 0.60 | 0.14 | 0.60 |
| Heading initiation | 1.65 | 0.385 | 1.65 |
| Heading–flowering | 0.51 | 0.119 | 0.51 |
| Maturity/harvest | 0.15 | 0.035 | 0.15 |
| Total | 3.0 | 0.7 | 3.0 |
*Actual total uptake may vary ±20% by region, cultivar, fertilization, and cropping system [2][3][4].
4.3 Validity of Estimation
Supported by:
- Japanese field guidance consistently states maximum uptake just before and during heading [1][2][3][4][6].
- California detailed tracking [7] and Arizona extension [8] provide numeric curves supporting global physiological similarity.
- Related Brassicas such as broccoli show similar trends [6][7].
5. Implications for Fertilization and Management
- Early growth promotion: Use basal fertilizer at seedling stage despite low uptake to avoid growth inhibition.
- Mid–late nutrient supply: Timely side-dressing from before heading through heading period.
- Avoid excess: Limit fertilizer after heading and at harvest to reduce disease and head splitting.
6. Future Tasks and Applications
Accumulating direct stage-by-stage measurements by cultivar and cropping system in Japan remains important. Estimation is practical but should be revalidated for local environments and systems.
Conclusion
- No direct g/m² primary data per stage exist in Japan, but estimation using total uptake and international absorption curves is standard.
- Maximum uptake occurs around heading initiation; timing and balance are critical in fertilization and field management.
- For totals such as N 3.0 g/m², P 0.7 g/m², K 3.0 g/m², allocating about 60% to heading initiation and the remainder to early and late stages is reasonable.
Sources
[1] Potential for reducing cabbage fertilizer on sandy fields - Aichi Prefecture: https://www.pref.aichi.jp/uploaded/attachment/34473.pdf
[2] Cabbage regional customary standards [chemical fertilizer]: https://www.pref.nagano.lg.jp/nogi/documents/16kyabetsu.pdf
[3] Cabbage fertilizer design for quality and yield: https://minorasu.basf.co.jp/80311
[4] Fertilizer application science - BSI cabbage: http://bsikagaku.jp/f-fertilization/cabbage.pdf
[5] Soluble phosphate in cattle manure compost for melon and cabbage - Kumamoto: https://www.pref.kumamoto.jp/uploaded/attachment/5064.pdf
[6] Nutrient uptake of vegetables: https://www.maff.go.jp/j/seisan/kankyo/hozen_type/h_sehi_kizyun/pdf/siryo5.pdf
[7] Cabbage yield and nutrient uptake - California Agriculture: https://californiaagriculture.org/api/v1/articles/110854-cabbage-yield-and-nutrient-uptake.pdf
[8] Cabbage: https://cales.arizona.edu/crop/soils/azncabbage.pdf