Manganese Sulphate: Uses in Agriculture and Industry
Manganese sulphate (MnSO4·H2O, CAS 10034-96-5) is the most widely used manganese fertiliser. Farmers apply it to the soil or as a 0.2% to 0.5% foliar spray to correct manganese deficiency, and manufacturers use it in micronutrient mixtures, agrochemical intermediates and animal feed. A good monohydrate grade carries 30.5% to 32% manganese.
This guide explains how common manganese deficiency is in Indian soils, how to spot and correct it, where the chemical is used outside the farm, and what to check on a specification sheet.
What is manganese sulphate?
Manganese sulphate is an inorganic salt sold mainly as the monohydrate, a white to light-pink powder that dissolves readily in water. That solubility is what makes it useful: it delivers manganese in a form plants can take up straight away, and it mixes cleanly into spray tanks and fertigation systems.
Retail fertiliser packs in India are commonly labelled at 30.5% manganese. Neshiel’s monohydrate grade is specified at 32% manganese minimum and 98.7% minimum purity on a dry basis.
How common is manganese deficiency in India?
An ICAR study under the All India Coordinated Research Project on Micro- and Secondary-Nutrients analysed 242,827 surface soil samples from 615 districts in 28 states. It found the following share of soils deficient in each nutrient (including latent deficiency):
| Nutrient | Soils deficient |
|---|---|
| Sulphur | 58.6% |
| Zinc | 51.2% |
| Boron | 44.7% |
| Iron | 19.2% |
| Manganese | 17.4% |
| Copper | 11.4% |
Source: ICAR, Deficiency of phyto-available sulphur, zinc, boron, iron, copper and manganese in soils of India. The same study found combined zinc and manganese deficiency in 3.4% of soils.
Roughly one soil in six is short of manganese. The problem concentrates where availability is chemically locked up. Manganese is most available at soil pH 5.0 to 6.5 and less available above that, so calcareous and alkaline soils are most at risk. Research from Punjab has focused on wheat grown after rice on coarse-textured soils, a common situation across the Indo-Gangetic plains.
Signs of manganese deficiency in crops
Manganese has low mobility inside the plant, so symptoms appear first on younger leaves. Look for:
- Yellowing between the veins while the veins stay green. In soybean, TNAU notes this differs from iron deficiency, where the veins also yellow.
- Brown spots and dead patches as the deficiency worsens.
- Stunted growth and, in tomato, narrower and longer leaflets with a reduced root system.
A soil test confirms it. For wheat, researchers set critical soil manganese levels of 1.25, 2.18 and 3.5 mg/kg for severe deficiency, deficiency and latent deficiency respectively (Springer study cited above).
How to apply manganese sulphate: dosage by crop
The recommendations below come from Tamil Nadu Agricultural University and ICAR research. Always confirm rates with a soil test and a local agronomist, because soil type and pH change the response.
| Crop | Foliar spray | Soil application | Source |
|---|---|---|---|
| Groundnut | 0.2% to 0.5% MnSO4 at fortnightly intervals | 5 to 10 kg/ha | TNAU |
| Soybean | 0.5% at fortnightly intervals | 20 to 25 kg/ha | TNAU |
| Tomato | 0.5% twice at a fortnightly interval | Not specified | TNAU |
| Wheat | Three sprays of 0.5% | Varies with deficiency level | ICAR, Indian Journal of Agricultural Sciences |
A 0.5% spray means 5 g of manganese sulphate per litre of water. In the ICAR wheat trial, foliar sprays raised grain yield by 0.30 to 0.85 tonnes per hectare depending on the variety.
Why foliar spraying often works better
On alkaline soils, soluble manganese applied to the ground converts quickly into forms roots cannot use, and soil applications can be hard to make effective. Foliar sprays bypass the soil. In the Punjab wheat research, three foliar sprays matched soil applications of 20 to 40 kg Mn per hectare. Soil application still has a place on acidic, sandy soils, and some growers combine a basal dose with follow-up sprays.
Monohydrate vs other forms
Manganese sulphate is also sold as the tetrahydrate and in chelated forms, and comparing them by price per bag is misleading. The manganese content is what counts.
| Form | Theoretical Mn content | Notes |
|---|---|---|
| Manganese sulphate monohydrate (MnSO4·H2O) | 32.5% | Most traded form; commercial grades 30.5% to 32% Mn |
| Manganese sulphate tetrahydrate (MnSO4·4H2O) | 24.6% | More water of crystallisation, so less Mn per kg |
| Mn-EDTA chelate | Usually around 12% to 13% | Costlier; used where soil pH or tank mixes cause precipitation |
Theoretical values are calculated from molecular weights. In practice, a 32% monohydrate delivers about a third more manganese per kilogram than the tetrahydrate.
Using manganese sulphate in fertigation
The monohydrate dissolves readily, which suits drip fertigation and water-soluble fertiliser blends. Dissolve it fully in clean water before injecting, keep it apart from phosphate concentrates in the stock tank (manganese and phosphate can precipitate together), and run a jar test before tank-mixing with pesticides or other nutrients. The water-insolubles limit on the specification matters most here, because undissolved particles block emitters.
Industrial uses of manganese sulphate
- Micronutrient fertiliser mixtures. Blended with zinc, iron and boron sources into grade-specific mixtures and water-soluble fertilisers.
- Agrochemical intermediates. Neshiel’s specification lists use as an intermediate for agrochemicals.
- Animal feed premixes. Manganese is an essential trace mineral for livestock and poultry, and the sulphate is a common source.
- Manganese chemicals and batteries. Manganese sulphate is a precursor to manganese metal and many manganese compounds, including electrolytic manganese dioxide used in batteries.
What to check when buying manganese sulphate in bulk
| Parameter | Neshiel specification | Why it matters |
|---|---|---|
| Manganese content | 32% minimum | The figure you are paying for; compare grades on Mn%, not price per bag |
| Purity (dry basis) | 98.7% minimum | Lower purity means more inert material per tonne |
| Moisture (LOD) | 0.3% maximum | Higher moisture causes caking in storage |
| Water insolubles at pH 5 | 0.1% maximum | Insolubles block spray nozzles and drip emitters |
| Appearance | White to light-pink powder | Off-colour can indicate iron or other contamination |
For fertiliser use, also confirm the product meets India’s fertiliser control requirements and ask for heavy-metal test results. For feed use, ask for a feed-grade certificate.
Neshiel supplies manganese sulphate monohydrate in 25 kg HDPE bags and in 1,000 kg, 1,200 kg and 1,250 kg jumbo bags. Blenders and fertiliser manufacturers usually take jumbo bags; distributors repacking for farmers usually take 25 kg bags.
Buying manganese sulphate for fertiliser, feed or chemical use? Get a quote from Neshiel for 32% Mn monohydrate in bags or jumbo bags, or see our industrial chemicals range.
Frequently asked questions
What is manganese sulphate used for in agriculture?
To correct manganese deficiency in crops, applied either to the soil or as a foliar spray, and as an ingredient in micronutrient fertiliser mixtures.
How much manganese sulphate should I spray per litre?
TNAU recommends 0.2% to 0.5%, which is 2 g to 5 g per litre, sprayed at fortnightly intervals once symptoms appear. Confirm the rate for your crop locally.
What is the difference between 30.5% and 32% manganese sulphate?
Both refer to manganese content. A 32% grade delivers more manganese per kilogram, so less product is needed for the same dose.
Can manganese sulphate be mixed with other fertilisers?
It is commonly blended with zinc, iron and boron sources. Check compatibility before tank-mixing with phosphate fertilisers or alkaline products.
