There is endless amounts of information to take in when it comes to Plant nutrition. With the focus on Fertiliser, Robert Megier of Everris has provided us with the answers to some common questions in the Landscape industry.

What factors are important to maximise fertiliser efficiency?

The physical, chemical and biological characteristics of the soil are important to maximise fertiliser efficiency. Plants take up nutrients in the form of dissolved ions in solution. It is important therefore that soil moisture levels are at a level suited to the particular species.

Just as important is the amount of oxygen available to plant roots. Different species will have different requirements as far as the air filled porosity of the soil is concerned. Chemical properties such as pH of the soil, the overall EC (electrical conductivity) of the soil and the balance of nutrients in the soil will also affect nutrient uptake.

Biological activity in the soil is also important, especially the balance between desirable microbes and pathogenic microbes. Soil structure is important in the factors – soil moisture, oxygen and microbial activity. If the soil allows good infiltration, drainage and the ability to hold moisture and oxygen, then the available nutrients can be maximised by the plant.

So if the soil is no good can you put more fertiliser on and that way it won’t be terribly efficient but at least you know the plants will get what they need?

Not necessarily. If the soil is very sandy and prone to high leaching, then yes, applying more fertiliser will be beneficial. However, if the soil is low in oxygen or is prone to water logging, then adding more fertiliser just adds salts which can’t be taken up by the plant and this adds another stress to the plant’s roots. Root health is the primary concern. When you have healthy roots you have the ability to maximise water and fertiliser use and to resist pests and diseases both above and below ground.

Is there any table of soil type and suitable fertiliser in landscaping?

There are no generalisations here. Only to repeat what we have already covered – that the entire root zone environment is important. That includes physical, chemical and biological characteristics. When these conditions are optimised the plant’s roots will be best able to utilise the water and nutrients available.