Organic and Inorganic Fertiliser
Although both organic and inorganic fertiliser are essentially used to promote lawn health
and vigour, there are several differences between the two fertilisers. Each type have their own
advantages and disadvantages to the lawn and soil etc.
Inorganic fertilisers are man made, chemical based products, while organic fertilisers are
derived from natural products or natural substances such as animal manure, blood and bonemeal
For countless years now, there have been debates and differing opinions amongst gardeners over
organic and inorganic fertiliser, and which type is more beneficial to the soil and the lawn.
The simple fact is that each type of fertiliser offer their own advantages to the lawn, at the
same time they both have their disadvantages too. However it is important to note that the grass
plant can't tell the difference between inorganic and organic fertilisers.
As the name suggests, organic fertilisers are derived from natural or living substances. These
substances include dried blood, hoof and horn, farm manure and bone meal. Inorganic fertilisers are
made from non-living materials and are chemical based.
The advantages of organic fertilisers
- Beneficial to the soil and root zone - Organic fertilizers do more than
supply the grass plant with vital nutrients, over a period of time they will help improve the
soil structure. Organic fertilisers also improve water retention within the soil, this
particularly beneficial during periods of drought stress, as it helps the lawn retain a healthy
coverage of grass.
- Grass growth is consistent - Organic feeds create slow, consistent plant
growth. This is because they have to be degraded by the soil microbes (micro organisms) prior
to them being released and absorbed into the grass plant. This process prevents any unwanted
surge or flush of grass growth.
- Greater longevity - Organic fertilisers have a greater longevity than
chemical or inorganic feeds, which all adds up to fewer applications being required to sustain
healthy plant growth.
- The supply of additional trace elements - Organics typically supply
additional nutrition to the grass plant in the form of trace elements (most inorganic formulas
don't contain additional trace elements).
- Safer to apply - How many times have you heard about people damaging their
lawns through fertiliser scorch, this is more common when applying inorganic feeds. There are
fewer problems with scorching or burning when applying organic feeds.
- Encourages healthier conditions - Organics encourage healthier soil
conditions, thus improving pest and disease resistance, with the end result being less problems
in the lawn. Encourages beneficial micro organisms - Organic fertiliser
encourages a healthy population of soil micro-organisms which are important for a healthy soil.
These soil microbes degrade organic matter, control thatch build up,
prevent lawn disease and break down chemicals and toxins in the
Disadvantages of Organic fertilizer
- Expensive to purchase - One of the drawbacks with organic feeds is the
purchase price, they are more expensive than inorganic feeds.
- Slower response times - Because organic feeds need to be broken down by
soil microbes before being available to the grass plant, the time they take longer to work than
inorganic feeds. Soil temperate can also be a factor, as soil microbes require warm soils.
- Application can be difficult - Organic fertilisers take on many forms such
as powder and meal, therefore applying them can often be difficult. Solid formulations may lack
a consistent particle size, or excess residue is regularly found in liquid feeds and may cause
sprayers and applicators to clog up.
Inorganic also known as synthetic or chemical fertilizers are man made, they are not derived
form natural sources.
Advantages of inorganic fertilizer
- Availability - As inorganic fertiliser is very common, then availability
is not going to be a problem. Many garden centers carry a large stock and a wide selection of
brands to suit most budgets and lawn requirements.
- A wide range nutrient combinations - Inorganic fertilizers are available
in wide variety of nutrient combinations, enabling you to find a product suitable for your
lawn. There is also a wide range fertilizers for different applications e.g spring and summer
feeds (high nitrogen) & autumn and winter feeds (high phosphate & potash).
- Quick response times - Inorganic fertilizers often ensure quick response
times. Results can often be witnessed within a few days of application.
- Easy to apply - As inorganic fertiliser is available in a variety of
formulations, such as liquids, granules, pellets and soluble, application is made easy for the
gardener. A range of different spreaders, sprayers and applicators are available for applying
these products. Another plus factor is many of these product come with information and advice
on spreader settings to ensure accurate calibration and application rates.
- Cheap to purchase - Inorganic fertilisers are less expensive than their
organic counterparts. However it should be noted that some inorganic feeds such as
slow and controlled release feeds can prove to be more costly.
Disadvantages of inorganic fertilizer
- Short life span - Inorganic or synthetic fertilizer have a shorter
longevity. This means additional applications have to be applied to maintain the correct level
of nutrition for the grass plant.
- Excess growth following application - Many inorganic fertilisers are fast
acting, the downside to this is an unwanted, initial flush of growth.
- Subject to leaching from the soil - As inorganic feeds are water soluble,
it is possible they can be leached through the soil and wasted, (especially following periods
of heavy rain fall) before the plant has chance to absorb them.
- Application problems - The danger with inorganic fertilisers is that if
they are not applied correctly (overdosing) they can damage the lawn by scorching the grass and
in some cases kill the grass.
- No real benefits to the soil - Inorganic fertilizers only feed the grass,
they will not improve the soil structure and increase micro organism populations, as organics