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Frequently Asked Questions

Agrisilica® contains high levels of monosilicic acid – Si(OH)4, known as Plant Available Silicon (PAS), plus calcium, magnesium and iron.
Silicon (chemical symbol Si) is a Group 4 element in the Periodic Table and, after oxygen, is the second most abundant terrestrial element. Silicon tends to want to form bonds with oxygen and various other elements (e.g. calcium, aluminium, magnesium). Monosilicic acid, silicic acid and othosilicic acid are different terminologies for the same compound Si(OH)4 and the only form of silicon which plants can absorb as a nutrient, known as Plant Available Silicon (PAS).

Interest has increased significantly with numerous scientific papers supporting the extraordinary
benefits of silicon in relation to agriculture. One of the leading world authorities, The Association
of American Plant Food Controls Officials (AAPFCO) has now officially designated Silicon (Si) as a
plant “beneficial substance”. This quasi-essential status means plant available silicon (PAS) may
be listed on fertiliser labels and regarded as delivering significant benefits to crops and soils.

Plants perform best when all required nutrients are taken up and available for utilisation. If one nutrient is lacking, then all nutrients are compromised because the plant’s biochemical process is limited. Therefore, PAS is required in similar quantities to other nutrients to optimise plant and soil health and productivity.

Yes. Agrisilica® in Chip and Powder products are certified for use in organic agriculture. For farming where drip and irrigation systems are required, our powder fertilisers are able to be used in hydroponic systems or in fertigation while kept in a suspension. For best results seek advice from your local agronomist.

(Please note - not all silicon fertilisers on the market are the same, some having gone through a process known as calcining which is a potential carcinogen, and some is sourced from slag which could be a source of toxic heavy metals which can be taken up by plants into the edible crop).

Plant available silicon:
  • Optimises healthy photosynthesis (ie: higher plant energy, more erect presentation, higher Brix content, etc)
  • Optimises uptake of all nutrients from the soil
  • Optimises all nutrient benefits within the plant
  • Sequesters carbon in plants which they convert to energy for growth
  • Sequesters carbon in soils which helps soils retain water and improves soil structure
  • Increases plant strength - root, stem, leaf, skin or husk (ie: reduces lodging)
  • Increases resistance to pathogens and insect attacks (ie: plant less disease susceptible and plant’s epidermal layer is stronger and more resilient to herbivorous attack)
  • Increases resilience to stress causes by drought and heat through lowered transpiration rates
  • Increases resilience to salt stress by inhibited absorption of sodium
  • Increases absorption and utilisation of nitrogen, phosphorus and potassium (NPK)
  • Increases tolerance of heavy metal toxicity (ie: iron, manganese, cadmium, zinc, mercury, arsenic and aluminium)
  • Increases cation exchange capability (CEC) enabling higher retention and uptake of nutrients and water
  • Increased carbon sequestration in plants.
In addition, Agripower’s Agrisilica® has a high Cation Exchange Capacity (> 30 cmol/kg) and a high water- holding capacity (holds > 150% its weight in water), making it a valuable soil amendment.
There are several reasons for this:
  • Silicon and the science of PAS in relation to plant and soil biology has historically not been well understood, and only in relatively recent times have substantial controlled and commercial trials been undertaken and their results analysed.
  • Silicon as a fertiliser additive has until now, been predominantly available via calcium silicate slags, which may contain heavy metals.
  • Silicon in crystalline form can pose health issues for humans and animals, and they contain little if any Agrisilica® contains high levels of PAS (derived from non-crystalline, silicon) is safe for animals and humans and now available at bulk scale for fertilisers.
  • Current farming practices remove naturally occurring plant available silicon, leaving soils depleted and exhausted. This is why crops are responding so well to Agrisilica®, as it replaces a much-missed nutrient in amounts needed to effect plant and soil health.
  • Abiotic and biotic stress are a major cause of annual crop loss globally. Recent commercial field trials with Agrisilica® are seeing significant reductions in crop losses from stress.
  • Bulk quantities of user-friendly Silicon fertilisers have been limited until now.
    • Agrisilica® 2-5mm granules are easy to spread and can be blended with NPK fertilisers
    • Agrisilica® Liquid Solution can be easily applied as a foliar application or through irrigation fertigation systems

All crops require Silicon. In fact, every living thing (plants, animals and humans) require Silicon for connective tissue and cell strength. Agripower has conducted more than 600 trials on over 46 different crops including grains, vegetables, tree crops, vines, sugar cane, sugar beet, strawberries and turf. Every crop Agripower has applied Agrisilica® to has responded positively.

Yes, it is now possible to test your soil and plant tissue for PAS. It is critical to measure using specific methods which Agripower can advise on for your situation.

The most important fact when selecting a silicon fertiliser is to understand the form of silicon in the product.
  • The key to silicon fertilisers is the amount of monosilicic acid or plant available silicon (PAS) in the product you buy.
  • Agrisilica® contains high amounts of PAS which can be taken up and used by plants as silicon in nutrient form.
  • A number of so-called silicon fertilisers claim high silicon levels but in fact contain very low monosilicic acid levels, meaning low plant available silicon - PAS.
  • It is PAS that is essential to health and productivity of your soils and crops.
  • Keep in mind, beach sand is over 90% crystalline silicon and contains little if any monosolicic acid / PAS.
The Agrisilica® fertiliser range is produced to suit all types of current and new technology farming. No special equipment or change of methodology is required. The range includes:
  • 2-5mm Granule
  • 0-2mm Granule
  • 2-8mm Chip
  • 300 micron Powder
  • 100 micron Powder
  • Liquid Solution.
Agrisilica® solid fertilisers release PAS in moist soil and continues to release as the plant requires. The length of time is dependent on soil type, soil pH, soil moisture, irrigation / rainfall levels and plant root activity. The silicon contained in Agrisilica® Liquid fertiliser is available immediately to plants.

Recommendations will vary depending on soil type and chemistry, crop type, target yields and likely stress events.

A soil test and consultation with an agronomist is advised to provide accurate recommendations.

General application rates are :

  • Field crops (e.g. wheat) : 150-300 kg/ha
  • Vegetable crops : 150-500 kg/ha
  • Tree crops : 300-600 kg/ha
  • Vines : 150-300 kg/ha
  • Strawberries : 500-750 kg/ha
  • Turf : 300-600 kg/ha

Agrisilica® can be applied as per:

Field crops

  • Banded at seeding / planting
  • Broadcast and incorporated prior to seeding / planting
  • Broadcast or banded post crop emergence or after planting


Tree crops and vines

  • Banded along drip lines - split applications are best
  • Broadcast under tree / vine drip line - split applications are best
Climate-Smart Agriculture (CSA) was developed in 2009 by FAO – Food and Agricultural Organisation of the United Nations – as a unified approach to address climate challenges in relation to agriculture and food security. The three main objectives are:
  1. Sustainably increase agricultural productivity and incomes
  2. Build resilience to climate change and variability
  3. Reduce and/or remove greenhouse gas emissions where possible.
Agrisilica® meets these global social, economic and environmental goals and challenges by:
  1. Optimising soil structure and condition by increasing soil flocculation and aggregation
  2. Optimising soil moisture levels (water retention without waterlogging)
  3. Optimising cation exchange capability (CEC) enabling higher retention and uptake of nutrients and water
  4. Optimising retention and release of water and nutrients to critical root zone
  5. Optimising absorption and utilisation of nitrogen, phosphorus and potassium (NPK)
  6. Optimising capacity to reduce chemical pesticides by 40-70%
  7. Optimising capacity to accelerate organic pesticide degradation in soil
  8. Optimising capacity to reduce traditional fertilisers by 10-40% while still returning increased yield
  9. Optimising reduction of nitrogenous fertiliser run-off and leaching by polymerising it into a more readily plant available form
  10. Increasing organic carbon and oxygen
  11. Increasing root mass (up to 200%)
  12. Increasing crop survival
  13. Increasing crop quality and taste
  14. Increasing crop yield
  15. Increasing crop value
  16. Increasing plant strength - root, stem, leaf, skin or husk (ie: reduced lodging)
  17. Increasing plant resistance to pathogens/insect attacks
  18. Increasing photosynthetic activity / (ie: higher plant energy, higher Brix content in fruits)
  19. Increasing crop resistances to Abiotic and Biotic stresses (responsible for up to 82% crop loss annually)
    1. Increasing plant resilience to drought and heat stress through lowered transpiration rates
    2. Increasing plant resilience to salt stress by inhibited absorption of sodium
    3. Increased plant tolerance of heavy metal toxicity (ie: iron, manganese, cadmium, zinc, mercury, arsenic and aluminium)
  20. Reducing leaching of fertilisers and nutrients into ground water, water systems and oceans
  21. Reducing plant uptake of sodium and heavy metal toxicity eg; aluminium
  22. Increasing carbon sequestration and reducing CO2, N2O and CH4 emissions by:
    1. promoting photosynthesis which increases root and vegetative biomass (particularly under stressful growing conditions such as drought, soil salinity, pests and disease): the increased plant biomass captures greater amounts of carbon.
    2. improving soil health on a chemical, physical and biological level: by improving soil structure (particularly sandy soils), the water holding capacity of soils is increased which improves the cation exchange capacity of the soil.
    3. improving soil health, soils become more efficient in soil biology, delivering improved plant growth and higher sequester more carbon.
    4. reducing chemical leaching, particularly nitrogen, due to its ability to retain moisture and its high cation exchange capacity, less GHG’s are emitted or ‘escape’ because they are under-utilised by both soils and plants
    5. increasing plant and soil phytoliths through introducing silicon in nutrient form enabling carbon can be captured – phytoliths can sequester carbon for 200-1,000+ years.
While some of the above points may seem repetitive, Agripower believes it important for you to know that while Agrisilica® can have direct benefits to plants or soils, it can also have additional flow-on benefits such reducing greenhouse gas emissions and pollution – we want to ensure you understand the larger, very exciting interconnected, cyclical benefits of farming with plant available silicon. Farming with Agrisilica® makes good environmental, social and economic sense.

We welcome your further interest in Agrisilica®

Please get in touch by email or phone Agripower on +61 2 9251 8884