Potash for sugar beet & root crop
- Potassium (K, potash: K2O) is essential for all crops and sugar beet requires large amounts.
- Soils should be maintained above the critical level for plant-available K, P and Mg to achieve optimum yields and quality of all the crops grown on the farm.
- For sugar beet, the critical level for potash is K Index 2-. Below this level, yield will be lost. Yields are not increased when soils are at K Index 3 and above.
- Crops need K where the roots can get it, i.e. throughout the soil explored by the roots. Sugar beet only very occasionally responds to freshly applied potash, and then only on soils with very low levels of available K (K Index 0). It is wise to regard applications of potash as part of the longer-term strategy to raise or maintain soil K at a suitable level rather than as a means of immediately increasing beet yields.
- Potassium in the ploughed-in tops is returned to the soil K reserve.
- To maintain adequate levels of soil K, the K removed in the harvested beet needs to be replaced on all soils below K Index 3. The quantity removed can be seen for individual contracts from British Sugar On-line.
- Sugar beet requires a small amount of sodium (Na). In addition sodium can substitute for some of the functions of potash; applying Na will be of benefit on K Index 0 and 1 soils and on soils low in available sodium.
REMEMBER: Once soil K has been adjusted to above the critical level it needs to be maintained at that level. This can be done by estimating the amount likely to be removed in the harvested beet before the sugar beet is sown or replacing the amount removed before the next crop is sown. Either way, the actual K status of the soil needs to be checked by soil sampling and analysis every 4-5 years. Because the K status of the soil can vary widely within a field, growers may wish to maintain their average soil K index closer to 2+.
The function of Potassium, Magnesium and Sodium in root crops
Use of Sodium (salt)
The BBRO Growers Guide & RB 209 Recommendations for Sodium
Potassium uptake & offtake by Sugar Beet
Fertiliser recommendations for Potash, Magnesium and Sodium
Timing of applications
K-Salt can be applied at anytime of the year prior to planting.
For soils at K Index 2- there are several potential benefits to be gained by applying the necessary K, Na and Mg in the late autumn and early winter prior to ploughing the land destined for the beet or root crop. Sugar beet has active roots at depth, but the main advantage of such early spreading is that the absence of newly applied nutrients in the seedbed is helpful to germination and the establishment of a good plant population. The fact that there will be no wheel-marks in the seedbed from the spreading and incorporation of these nutrients is another significant benefit.
JSE-Systems operate a fleet of high capcaity belt spreaders suitable for spreading K-Salt and can deliver up to 10t directly in the spreader; with in a 50km radius of Ancaster, Lincolnshire.