Leonardite Humic Acid Soil Conditioner: Source, Composition, and How It Works

SoilBoost EA, a leonardite humic acid soil conditioner manufactured by Chemiseed in Malaysia

Leonardite is a soft, naturally oxidised form of lignite (brown coal) and one of the richest natural sources of humic substances, both humic and fulvic acids. SoilBoost EA is a soil conditioner derived from 100% leonardite ore, manufactured exclusively by Chemiseed Sdn. Bhd. in Malaysia. It is rich in humic and fulvic acids, chelates micronutrients, and improves how soil holds and delivers nutrients. It is a soil conditioner, not a fertiliser, and does not replace one.

Quick facts

  • Source: 100% leonardite ore (oxidised lignite), one of the richest natural humic deposits
  • Active fractions: leonardite-derived humic acid plus an active fulvic fraction, described qualitatively
  • Also present: chelated micronutrients (iron, zinc, copper) and approximately 0.45% sulphur; pH 3.84
  • Role: soil conditioner, not a fertiliser, fungicide, or pesticide
  • Product: SoilBoost EA, manufactured exclusively by Chemiseed Sdn. Bhd., Malaysia

What is leonardite?

Leonardite is a soft, brown, highly oxidised form of lignite (brown coal). It sits near the surface above older coal seams, where long, slow oxidation broke down and concentrated its organic matter into humic substances. That is why leonardite is one of the richest natural sources of the humic and fulvic acids used in agriculture: gram for gram it carries far more humic material than compost, peat, or raw manure, so a small, consistent dose delivers a known quantity of humic substances rather than a variable one.

Composition of a leonardite soil conditioner

SoilBoost EA is produced from 100% leonardite ore and is rich in humic and fulvic acids. Extractable humic figures vary with the laboratory method used, so the humic content here is described qualitatively rather than as a single headline number. The confirmed specification is:

Source material 100% leonardite ore (oxidised lignite)
Humic and fulvic acids Rich in both; humic acid is the major active fraction, with a lighter, mobile fulvic fraction that carries micronutrients into the plant
Chelated micronutrients Iron, zinc, and copper held in plant-available form
Sulphur Approximately 0.45%
pH 3.84 (acidic; suits neutral-to-alkaline tropical soils applied at low rates)
Manufacturer Chemiseed Sdn. Bhd., Malaysia (exclusive maker)

How leonardite humic acid works

Leonardite humic acid conditions soil through four well-documented pathways:

1. Nutrient chelation

Humic and fulvic molecules form stable, water-soluble complexes with iron, zinc, and copper, keeping these micronutrients bioavailable to roots instead of precipitating in the soil.

2. Cation exchange capacity

The high charge density of humic acid raises the soil cation exchange capacity, so the soil holds and exchanges more potassium, calcium, magnesium, and ammonium and loses fewer of these cations to leaching in heavy rain.

3. Gene upregulation

Humic substances can activate the root nitrate-uptake machinery, including transporter and proton-pump genes such as NRT2.1 and MHA2, which is associated with improved nitrogen-uptake efficiency.

4. Organo-mineral complexation

Humic acid binds minerals and labile carbon into stable aggregates, protecting soil carbon, improving structure and aeration, and building long-term fertility.

What the research shows

Independent research on leonardite and humic substances supports these mechanisms. A 2024 meta-analysis in Agronomy (MDPI; Ma et al.) reported that humic-acid application raised average crop yield by about 12%, nitrogen-use efficiency by about 27%, and nitrogen uptake by about 17% versus untreated controls. An earlier meta-analysis in Advances in Agronomy (Rose et al., 2014) found that humic substances increased shoot dry weight by roughly 22% and root dry weight by roughly 21% on average, with the strongest responses, around 28%, under high-stress conditions. These figures come from the wider humic-acid literature, not from SoilBoost EA trials specifically. For SoilBoost EA field data, including the FPA EUP 3227 banana trial, see the Evidence Hub.

Why it matters for tropical plantations

Humic acid gives its strongest and most consistent response under a specific set of conditions: moderate-pH soils (roughly 6 to 8), rainfall above about 300 mm, and low baseline soil nitrogen. Those conditions describe much of Southeast Asia. On oil palm, rubber, cocoa, durian, and coconut estates, high rainfall leaches potassium, calcium, magnesium, and ammonium out of the root zone, while weathered tropical soils often hold nutrients poorly. By raising cation exchange capacity and chelating micronutrients, a leonardite humic acid helps these soils retain and deliver nutrients between fertiliser applications, which is where the nutrient-use-efficiency gains reported in the literature tend to come from.

SoilBoost EA: our leonardite soil conditioner

SoilBoost EA is Chemiseed's leonardite humic acid soil conditioner, produced from 100% leonardite ore and manufactured exclusively by Chemiseed Sdn. Bhd. in Malaysia for oil palm, rubber, fruit trees, and other tropical crops. It supports nutrient uptake and soil structure and is used alongside your existing fertiliser program. SoilBoost EA is a soil conditioner, not a fertiliser, fungicide, or pesticide, and it is not a treatment for Fusarium TR4, Phytophthora, or any plant disease; it supports soil health and nutrient uptake rather than controlling pests or pathogens. View SoilBoost EA (25 kg), choose the smaller SoilBoost EA 1 kg, or size a dose with the application-rate calculator.

Frequently asked questions

What is leonardite?

Leonardite is a soft, naturally oxidised form of lignite (brown coal). Slow oxidation concentrated its humic substances, which is why it is regarded as one of the richest natural sources of humic and fulvic acids used in agriculture.

Is leonardite the same as humic acid?

Not quite. Leonardite is the raw ore, and humic and fulvic acids are the active substances extracted from it. Humic acid is the major fraction, while fulvic acid is a lighter, more mobile fraction that helps carry micronutrients into the plant.

How is leonardite used on plantations?

It is applied as a soil conditioner, typically by broadcasting, fertigation, or per-tree dosing, alongside the usual fertiliser program. Rates depend on the crop, soil, and method, so growers size the dose with an application-rate calculator rather than a single fixed rate.

Does SoilBoost EA come from leonardite?

Yes. SoilBoost EA is made from 100% leonardite ore and is manufactured exclusively by Chemiseed Sdn. Bhd. in Malaysia.

Is it a fertiliser?

No. SoilBoost EA is a soil conditioner, not a fertiliser, fungicide, or pesticide. It does not supply significant NPK on its own; it improves how the soil holds and delivers nutrients, so it complements rather than replaces fertiliser, and it is not a treatment for any plant disease.

What crops benefit?

Leonardite humic acid tends to help most in moderate-pH, higher-rainfall soils with low baseline nitrogen, conditions common to Southeast Asian oil palm, rubber, cocoa, durian, and coconut estates. Results still vary with soil type, rate, crop, and management.

Related resources

Use leonardite humic acid on your soil

SoilBoost EA is Chemiseed's leonardite humic acid soil conditioner, manufactured exclusively in Malaysia for oil palm, rubber, fruit trees, and tropical crops. View SoilBoost EA, request a quote, or size a dose with the application-rate calculator.

Note: Leonardite humic acid is a soil conditioner, not a fertiliser, fungicide, or pesticide, and is not a treatment for Fusarium TR4, Phytophthora, or any plant disease. It supports soil health and nutrient uptake; it does not control or cure pests or pathogens. Independent yield and nitrogen figures are from the general humic-acid literature (Ma et al. 2024; Rose et al. 2014), not from SoilBoost EA trials, and results vary with soil type, rate, crop, and management. SoilBoost EA values (pH 3.84, approximately 0.45% sulphur) are from product testing. Last reviewed July 2026.