Organic Fertilisers: What Actually Replaces Urea and DAP

The hardest mental switch in going organic is not learning new inputs — it is unlearning the one-bag-one-nutrient logic of synthetic fertiliser. A bag of urea is 46% nitrogen; you know exactly what you are buying and the plant takes it up within days. Organic fertilisers do not work that way, and pretending they do is why first-year conversions so often disappoint.

Organic systems feed the soil, not the plant. You add organic matter; soil microbes break it down and release nutrients slowly across the season. That is slower and less precise than a urea top-dress — and it is also what rebuilds the soil that continuous chemical use runs down.

The building blocks

No single organic input replaces the fertiliser shelf. You combine a bulk organic source, a concentrated nutrient source, and a biological one.

Every rate above varies with crop and soil. Your soil health card, free under the government scheme, is worth more than any table here — most Indian soils are short of a specific micronutrient, not of everything at once.

Why FYM alone is not enough

Farmyard manure is the foundation, and on most farms it is the single biggest organic input. But two things limit it:

It is low in phosphorus. A fruiting or flowering crop — tomato, chilli, any pulse setting pods — needs phosphorus that FYM cannot supply in time. Pair it with bone meal, rock phosphate, or a PSB culture.

Fresh dung is a mistake. It has to be composted first. Fresh dung composts thermophilically, robs the soil of nitrogen as it breaks down, and carries weed seed and pathogens. Use it well-rotted — dark, crumbly and cool — never straight from the shed.

Building the nitrogen, over years

Nitrogen is where organic farming is most often misunderstood. There is no organic urea. Instead you build a soil that supplies nitrogen itself:

• A legume in the rotation — gram, moong, a green manure — fixes atmospheric nitrogen through root nodules and leaves it for the next crop.
• Oil cakes (neem, mustard, castor) are the most concentrated organic nitrogen you can buy, at 4–5% N, and neem cake suppresses soil pests as a bonus.
• Biofertilisers — Azotobacter and Azospirillum for cereals, Rhizobium for pulses — add nitrogen-fixing bacteria directly.

This is why the conversion window is 2–3 years. You are not swapping one input for another; you are rebuilding the soil's own nutrient supply, and that takes seasons.

A workable combination

For a general kharif or rabi field crop on average soil, a starting programme looks like:

1. Basal: 4–6 t/acre well-rotted FYM or 2 t vermicompost, worked in before sowing, plus a phosphorus source for fruiting crops.
2. Seed treatment: the appropriate biofertiliser culture (Rhizobium for pulses, Azotobacter for cereals; PSB for all).
3. Top-up: one or two foliar sprays of jeevamrit or a 2% oil-cake extract at the crop's active-growth stages.
4. Next season: a green manure or a legume before the main crop, ploughed in to keep building the soil.

Change every figure to your crop and soil. The programme matters less than the principle: a bulk source for organic matter, a concentrated source for the nutrient your crop is short of, and a biological source to keep the soil alive.

Worth remembering

Organic fertility is cumulative. The field that has had compost and a legume rotation for three years feeds itself far better than the one converted last month — same inputs, very different result. Start building soil organic matter now, even before you decide to certify, and the conversion is far easier when you come to it.

Frequently asked questions

Can organic fertilisers fully replace urea and DAP?

Yes, but not one-for-one and not overnight. A single bag of urea carries 23 kg of nitrogen; matching it takes several tonnes of FYM. Organic systems feed the soil rather than the plant, so the nitrogen is released slowly by soil microbes over the season — which is why building organic matter over two or three years matters more than any single input.

How much compost is needed per acre?

As a general guide, 2–4 tonnes of well-rotted FYM or 2–2.5 tonnes of vermicompost per acre per season, adjusted to the crop and your soil health card. Vegetables and potato need the higher end; cereals and pulses need less.

Which organic fertiliser gives nitrogen, and which gives phosphorus?

For nitrogen: FYM, vermicompost, oil cakes (neem, mustard, castor) and biofertilisers like Azotobacter and Rhizobium. For phosphorus: bone meal, rock phosphate and phosphate-solubilising bacteria (PSB). Wood ash and crop residue supply potash.

Is cow dung a complete fertiliser?

No. Farmyard manure is the base of every organic system and supplies organic matter and a broad spread of nutrients, but it is low in phosphorus and slow to release nitrogen. It works best combined with an oil cake, a biofertiliser and, for fruiting crops, a phosphorus source.

Compiled by

Technical Kisan Editorial

Editorial Desk

Guides are compiled by the Technical Kisan editorial desk from ICAR and state agricultural university recommendations, and from central and state government scheme notifications. Every figure is labelled with the season it applies to. Always confirm against the official notification before acting on it.

• Compiled from ICAR and state agricultural university guidance
• Scheme details sourced from official notifications
• Figures labelled with the season they apply to

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