Should I use liquid or solid fertiliser on my pastures?

Published 4th November 2021
Pasture and Soil All Studies

In theory, there is no or little difference in terms of efficiency between nutrients supplied by a granular/dry fertiliser or a liquid fertiliser on your pastures, but they both have advantages depending on the application.

In this article, we consider as a fertiliser any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. We also acknowledge that fertilisers can also be organic and used on organic farms. 

Granular/dry fertilisers

Dry fertilisers are generally incorporated into granules – reason why often call them granular fertiliser instead of dry or solid fertiliser. Granular fertiliser allow a greater range of blends. Fertiliser blends can be created by mixing different fertiliser (mind the proper ratio!) to create the desired effect. Dry fertilizers can be ground-applied as a broadcast – meaning spreading the fertiliser evenly over the soil surface with or without working it into the soil, or applied as sidedress and cultivated shallowly into the soil. When farmers have access to custom blended granular fertiliser, they can fine-tune their pasture fertility program and potentially improve pasture production efficiency. 

Liquid fertilisers

The use of liquid fertilisers have largely increased in popularity in recent years. They can be either ground applied or foliar applied. Liquids can be broadcast, used in a band application at planting and as mid-season sidedress. When foliar applied, the plant nutrients are absorbed through the leaves and are more readily available for plant use than if ground applied. However, the availability of foliar-applied nutrients is short-lived and not continuous for the rest of the growing season. Foliar applications are a good way to correct mid-season deficiencies or supplement soil-applied nutrients.

Liquid vs Solid fertiliser

  Liquid fertiliser Solid fertiliser
Spatial In liquid form, they are more mobile in the soil water solution. The distance from plant roots to fertilizer nutrients. Less mobile nutrients like phosphorus can’t get closer than the individual granule containing them.
Salt content Liquids are often preferred for “starter.” Granular fertilizers can be “hot.” Roots can steer away from a band of granular fertilizer that contains high levels of nitrogen and potassium.
Consistency The nutrient content is identical in every drop of liquid fertiliser. Granulars have individual nutrient components in each granule.
Equipment The cost of converting equipment to handle liquid fertilizer can be an obstacle. The equipment is supposed to be cheaper but also doesn’t offer to handle both types of application.

 

Advantages of each type of fertilisers

Liquid fertiliser Solid fertiliser
Ease of handling and application (once set up) Often cheaper
Ease of blending and Uniformity of application Easier to store (does not “settle out” over time or “salt out” in cold weather)
Starter and in-season application More efficient for heavy pre-plant applications
Blend with pasture protection products Slow-release options (polymer-coated urea)

 

Did you know?

For farmers wanting to use both granular and liquid fertiliser, the Hustler Applic8r range offers an optional induction hopper, the ErgoMax™. ErgoMax™ is a pre-mixing system that allows the operator to pre-mix powders, granulars or any chemicals from waist height for extra convenience. Designed with a sluce feature and container rinse nozzle to simplify clean up and is fully sealed to prevent dust from entering the hopper during transport and contaminating your spray.

 

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And if you want to explore the fertiliser topic further, find an interesting review conducted by the Fertiliser Association of New Zealand:

Review of research on pasture yield responses to fine particle application of fertiliser in New Zealand.