All nutrition applications must be determined in association with an approved soil Analysis. Correct nutrition is critical. If too much N is used, maturity and bulking will be delayed, reducing the field yield.
Most agricultural soils other than organic soils (peats) are depleting in organic matter (OM) and hence manures are applied to build OM. Available nutrients and application rates are unreliable. Care should be taken to test applied manures for nutrient content and availability and these more accurate figures used to reduce artificial inputs.
Nitrogen is essential for good haulm development. Markies has strong, vigorous foliage characters. High levels of Nitrogen may delay tuberisation and therefore delay maturity and reduce yield.
| Soil Index | 0 | 1 | 2 |
|---|---|---|---|
| Markies | 120 | 80 | 50 |
On light soils and irrigated soils Markies may respond to top dressing (40-50 Kg N) between emergence and tuber initiation. Where heavy irrigation is used regular feeding with folia Nitrogen is also advised. For highly fertile silts and Black Fens soils use nitrogen index of 2.
P2O5 will help to encourage and develop tuber numbers, but the response is less from high soil indices. Markies will naturally produce moderate tuber numbers. Foliar applied phosphorus applied singly or split before and at tuber initiation is recommended. All base phosphate should be applied in the seedbed just prior to planting.
| Soil Index | 0 | 1 | 2 | 3 | 4 |
|---|---|---|---|---|---|
| Markies | 270 | 230 | 180 | 130 | 50 |
Phosphate of any grade will lock up 10-20 days after application. The finer the particle to start with then, in theory, the faster will be the conversion back from Appatite to plant available phosphate
Potato plants absorb large quantities of K, therefore adequate amounts of the nutrient need to be supplied. K2O will help increase tuber size and high applications may reduce dry matter content according to some sources. Potash should be applied in the Autumn / early Spring or at least 6 weeks prior to planting on low index soils. Limit the amount of Muriate of Potash (MoP) at planting to 150 - 200 kgs/Ha depending on soil index. High rates of MoP applied late can cause damage to sprouting seed especially if soil conditions encourage salinity.
| Soil Index | 1 | 1+ | 2- to 2 | 2+ | 3- to 3 | 3+ |
|---|---|---|---|---|---|---|
| Ppm | < 90 | 90 - 120 | 120 - 180 | 180 - 240 | 240 - 320 | 320 - 400 |
| Markies | 375 | 360 | 350 | 325 | 250 | 240 |
Is an essential element for good crop production. Check levels by soil tests and apply as necessary at planting. Early application of Kieserite (MgSO4) is preferred. In periods of heavy rain or irrigation Mg may be leached from soils. Foliar Mg applied with blight sprays is an effective way of supplying Mg in the appropriate formulation.
| Soil Index | 0 | 1 | 2 | 3 |
|---|---|---|---|---|
| Markies | 150 | 75 | 50 | 25 |
Best results are achieved using Kieserite close to planting.
Potatoes remove little Ca from the soil, however there can be a high requirement in the growing plant, particularly at the later growth stage.
Decreases in pollution has caused a major reduction of industrial S deposition. Check on recent history and levels of S in the growing crop. Symptoms appear as early senescence. Deficiencies can be rectified by prior application of foliar SO4 products such as MnSO4 and MgSO4. Sulphur can also be included in the base fertiliser in maintenance quantities.
Historic experience will show if the plant needs Mn