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Potassium Humate

Potassium Humate and Humic Acid

Potassium Humate Introduction

Humic acid is naturally occurring, organic substance found more in forest soil and rich in oxidized low rank coal, lignite, peat, etc. It is not a substitute to chemical fertilizers and bio-fertilizers. It increases water retention, retains nutrients and enhances microbiological activity, enzymes in soil, etc.

The organic matter on biodegradation is converted in to humus, which contains humic and fulvic substances. The humic substance contains various functional groups of carboxylic, carbonyl, phenolic, alcoholic with higher molecular weight of 40,000 to 70,000 and higher cation exchange capacity (100-130 meq/100 gm). Lignite contains more of humic acid. Whereas some of the oxidized coals contain higher content of fulvic acid; both of them are plant growth stimulant and beneficial to crops.

General Properties and Constituents

pH : 8.0-9.5

CEC : 100-130 meq/100 g

Carbon & Oxygen : 90-95 %

Nitrogen & Hydrogen : 3-5%

Organic Carbon : 18.0-22.0%

It also contains plant nutrients such as nitrogen, potassium, calcium, sulphur, manganese, iron, molybdenum (0.10-6.0%), copper, zinc, magnesium, boron (20-200 ppm), etc. It is soluble in water and has high biological activity in soil conditions.


All commercial crops, cereals, pulses, oilseeds, vegetables, trees, orchards, green house crops, ornamental plants, grass lawns and nurseries can be sprayed with potassium humate in soil before planting and foliar spray in two or three stages on plants before flowering for best results. Potassium humate can be mixed with organic manures and fertilizers, applied as seed soaking treatment, root application, foliar application or used directly during fertigation.

Soil application

Liquid potassium humate may be applied 35 ml/m2 area before planting / sowing / during irrigation. For aged or grown up trees, the dosage can be increased to about @ 200 ml per tree. Solid potassium humate may be applied @ 10 kg/hectare for all crops.

Foliar spray

One liter of liquid is diluted in 30 liters of water and sprayed to all crops before flowering, ornamental plants and grass lawn; once in 30 days in morning or evening for better results and may be combined with fertilizer spray also.

Mode of Action

The quinoidine and active acids within the liquid product of potassium humate have strong potentiality of oxidation, which restrains the activities of free radicals and hence, avails the development of the foliage and positively influences plants metabolism, photosynthesis, respiration, activity of ferments. Potassium, acting on the cell level, facilitates the absorption of nutrients by the roots and the exchange of gases through the stomata; this element is also a vital constituent of chlorophyll, speeding up photosynthesis. Potassium Humate alleviates the toxicity of pesticide residue and prevents soil from contamination of heavy metallic ions as well as other harmful matters. The high Cation Exchange Capacity of the product improves the utilization of fertilizers. It combines with such elements as Nitrogen, Phosphorus and Potassium which constitute in highly-efficient multi-function compound fertilizers.

Functions of Potassium Humate

1.Promoting the formation of good soil structure, increasing the cation exchange capacity (CEC), water-holding capacity, and the capacity of fertilizer retention.

2. Promoting nutrient uptake by plants and enhances the soil’s ability to chelate nutrients and to promote exchange of nutrients between plants and the fertilizers being applied. Thereby reducing the loss of applied fertilizers from leaching and run off. Because they are already a part of a certain organic structure, the humates chelate complexes with microelements can penetrate into the cell more easily than ordinary ions.

3. Stimulating beneficial microbial activity and root growth. Long-term research showed that humic substances bond many organic and non-organic substances into poorly soluble or insoluble compounds, so it reduces the toxic effect of residual amounts of herbicides, soil polluting radio nuclides, heavy metals, and other harmful substances, as well as radiation and chemical contamination.

4.Improve crop stress-resistance ability, it has been proved that the humates help to fight the effect of droughts and ensures their drought resistance. Long-term experience in the use of humates has shown that their presence is important during all stages of plants’ development but particularly vital in the early stages. The pre-planting treatment of seeds is very important. Even before germination begins, vital forces are awakened, and the immune system is stimulated.

5. Increase the yield and quality of various crops. Humates contain more biologically active components, and it directly affects their use.

Potassium humate (A Salt of Humic Acid) Benefits

Physical Benefits

Humic acids physically modify the structure of the soil.

Improve the structure of soil: Prevent high water and nutrient losses in light, sandy soils. Simultaneously convert them into fruitful soils by way of decomposition. In heavy and compact soils, aeration of soil and water retention is improved; cultivation measures are facilitated.
Prevent soil cracking, surface water runoff and soil erosion by increasing the ability of colloids to combine.
Help the soil to loosen and crumble and thus increase aeration of soil as well as soil workability.
Increase water holding capacity of soil and thus help resist drought.
Darken the color of the soil and thus help absorption of the sun energy.

Chemical Benefits

Humic acids chemically change the fixation properties of the soil.

Neutralize both acid and alkaline soils; regulate the pH-value of soils.Improve and optimize the uptake of nutrients and water by plants. Increase buffering properties of soil.Act as natural chelator for metal ions under alkaline conditions and promote their uptake by the roots.Rich in both organic and mineral substances essential to plant growth.
Retain water soluble inorganic fertilizers in the root zones and reduce their leaching.Possess extremely high cation-exchange capacities.Promote the conversion of nutrient elements (N, P, K + Fe, Zn and other trace elements) into forms available to plants.

Enhance the uptake of nitrogen by plants.
Reduce the reaction of phosphorus with Ca, Fe, Mg and Al and liberate it into a form that is available and beneficial to plants. The productivity of particularly mineral fertilizers is increased considerably.Liberate carbon dioxide from soil calcium carbonate and enable its use in photosynthesis.Help to eliminate chlorosis due to iron deficiency in plants.Reduce the toxic substances in soils.

Biological Benefits

Humic acids biologically stimulate the plant and the activities of micro-organisms.

Stimulate plant enzymes and increase their production.Act as an organic catalyst in many biological processes.Stimulate growth and proliferation of desirable micro-organisms in soil.Enhance plant’s natural resistance against disease and pest.Stimulate root growth, especially vertically and enable better uptake of nutrients.Increase root respiration and root formation.

Promote the development of chlorophyll, sugars and amino acids in plants and aid in photosynthesis.
Increase vitamin and mineral content of plants.Thicken the cell walls in fruits and prolong the storing and shelf time.Increase germination and viability of seeds.Stimulate plant growth (higher biomass production) by accelerating cell division, increasing the rate of development in root systems and increasing the yield of dry matter.Increase the quality of yields; improve their physical appearance and nutritional.

Humic acids chelate nutrient compounds, especially iron, in the soil to a form suitable for plant utilization. Thus, the nutrient supply of plants is optimized. High increases up to 70% in yield, accompanied by a reduction up to 30% in the use of fertilizers and pesticides, as well as better and healthier growth of green grass, ornamentals, agricultural crops and woods can be attained with the regular application of first-quality humic acids. Furthermore, water holding capacity of soils is increased considerably, which means that the use of water can be reduced substantially.Best economic results can be obtained in light and sandy soils poor in humus as well as on re-cultivation fields.

The diverse positive impacts of humic acids are to be observed particularly in such soils. This is true for almost all soils in dry and warm regions. As a result of the high mineralization rate of organic substances, providing these soils with stable humic acids is indispensable for the maintenance and improvement of soil fertility.Trials conducted by Tamil Nadu Agricultural University (TNAU), Coimbatore for four years in various agro-climatic conditions in their experimental stations as well as in farmers’ fields on various crops using the potassium humate produced by Neyveli Lignite Corporation (NLC) Ltd, Neyveli have revealed increase in yield of crops over control. Some of the research findings are given below:

Sl # Crop Improvement in yield
1. Rice 2.5 to 22.4%
2. Sugarcane 5.1 to 24.1%
3. Groundnut 14.0 to 27.2%
4. Pulses 14.3 to 27.7%
5. Cotton 15.4 to 24.4%
6. Tomato Maximum 16%
7. Onion (dried) Up to 47.83%
8. Tea Up to 30.00%


It has been proved that the crop yields have increased from 10 to 30 per cent apart from reduction of chemical fertilizers, which adversely affects environment. The product is presently imported from other countries. The product has large potential for use in agriculture and horticulture especially for food crops, commercial crops like spices, pulses, grapes, coffee, tea, cashew, cotton, fruit-bearing trees and apart from vegetables.

As per an empirical study carried out by the NLC team, with the cropping pattern in India with the cultivable land of 140 million hectares, the potassium humate requirement will be about 6.2 billion liters and with a market penetration of just 10%, the demand will be 620 million litres. NLC has proven technology for the manufacture of potassium humate from lignite on a pilot plant scale with a capacity of 3,60,000 liters per annum.

It is felt that there is a huge market potential for the application of the product in the Indian agriculture with appropriate marketing and promotional activities.