Agronomy Advice

Increase potato yield with better phosphate management

Getting potatoes to a good start is vital and ensuring sufficient phosphate is available for critical early root growth is key to this. So perhaps it is time you had a re-think about phosphate and considered the benefits of compound NPKS fertilisers rather than DAP.

Potato farmer grower and yara agronomist reviewing potatoes
Potato farmer grower and yara agronomist reviewing potatoes

Getting any crop off to a good start is vital but for potatoes ensuring sufficient phosphate is available is one of the keys to unlocking the maximum yield potential.

Phosphorous is particularly important for root development

A nutrient that is particularly important for potato establishment is phosphorus. Phosphate has an important role in the development of shoots and in particular roots and this is why a sufficient supply is key in the early stages of potato crop.   The problem here is that phosphate is relatively immobile in the soil and relies on the roots being able to grow towards it rather than the phosphate moving through the soil towards the roots.  Couple this with the fact that potatoes are a particularly poor rooted crop and in the early stages often struggle to establish an effective root network capable of accessing water and other nutrients and you can see why this is an issue.

There are several ways to improve management of phosphate in potatoes by using YaraMila compound fertilisers rather than more traditional 'straight fertilisers'.

Better timing of P and K applications ensures that the phosphate is applied close to when the plant requires, so limiting the amount that becomes locked up by the soil.  This is favoured by applying P and K as compound fertiliser at or just after planting rather than as separate 'straight' applications prior to planting.

Use a fertiliser with an extended phosphate supply

Choosing a form of phosphate which not only supplies readily available phosphate but also maintains a supply of phosphate over time also avoids problems of 'lock-up'.  Lock up is where the available phosphate becomes bound up in the soil as either iron or aluminium phosphate at low pH or as calcium phosphate at higher pH.  YaraMila compound fertilisers contain phosphate in the form of P-Extend which supplies available phosphate over an extended period to avoid potential lock up in the soil.

YaraMila compound fertilisers all contain each nutrient in every granule

Better distribution of phosphate through the soil profile also helps plant uptake.  The best way to achieve this is to increase the number of fertiliser particles. Traditionally phosphate has been applied as relatively concentrated DAP di-ammonium phosphate, containing 21% P so there are relatively few concentrated particles.

Similarly if the phosphate is applied in a blended fertiliser using DAP or MAP there is still the same problem of the phosphate being contained in relatively few particles resulting in a an uneven distribution of nutrient through the soil. 

However, if phosphate is applied as a compound fertiliser such as YaraMila Actyva S instead then every single prill or granule contains all nutrients and at a concentration of 6%  P there will be approximately three times as many particles.  This leads to more even spreading and a more effective distribution of nutrients throughout the soil which inturn leads to more even crop growth and increased yield


Fertiliser with extended phosphate supply

YaraMila fertilisers all contain P-Extend which provides an extended supply of phosphate to ensure it is available when required by the crop.