Neem Cake: Slow Nitrogen That Also Fights Nematodes
Neem cake is what is left after neem oil is pressed from the kernel — an oilseed cake that feeds the crop slowly and suppresses root-knot nematodes at the same time. Here is how much to use, when, and why it doubles as a nitrification inhibitor.
Technical Kisan Editorial2 min read
Press the oil out of a neem kernel and what remains is neem cake — a brown, strong-smelling residue that is one of the more useful organic inputs on an Indian farm. It does two jobs at once: it feeds the crop a slow ration of nitrogen, and it suppresses root-knot nematodes in the soil it is worked into.
What it supplies
| Nutrient | Typical range |
|---|---|
| Nitrogen (N) | 4–5% |
| Phosphorus (P) | ~1% |
| Potassium (K) | 1–2% |
Alongside the NPK it carries sulphur, calcium and micronutrients, and — crucially — residual azadirachtin and salannin, the same neem compounds that make neem oil spray work, left behind in the cake.
The nematode and nitrogen double act
Two things make neem cake more than just another oil cake:
- Nematode suppression. Worked into the root zone, the residual neem compounds and the flush of soil biology it feeds hold down root-knot nematode numbers — a real problem in vegetables, banana and many pulses.
- Slow nitrogen with less loss. Neem cake releases its nitrogen gradually and slows nitrification — the conversion of ammonium to nitrate that leaches away. The crop gets a steadier supply and less is lost.
How and when to use it
- Rate: about 100–250 kg per acre, leaning to the higher end where nematodes are a concern.
- Timing: work it into the soil at land preparation, or apply with FYM or compost a couple of weeks before sowing so it starts breaking down.
- Placement: broadcast and incorporate, or band near the root zone for nematode-prone crops.
What it is good and bad at
Good at: a slow, low-loss nitrogen source that also suppresses nematodes and feeds soil biology — a genuine two-in-one.
Weak at: fixing a phosphorus or potash shortfall (it is nitrogen-led), or acting fast — it is a build-the-soil input, not a quick corrective. Pair it with bone meal for phosphorus and wood ash or compost for potash to round out the ration.
Frequently asked questions
How much neem cake per acre?
For most field and vegetable crops, roughly 100–250 kg per acre, worked into the soil at land preparation or applied with FYM/compost. Higher rates within that band where nematode pressure is a concern; lower where it is mainly a nitrogen top-up.
Does neem cake really control nematodes?
It suppresses them rather than eradicating them. Residual azadirachtin and related compounds, plus the way neem cake feeds beneficial soil organisms, reduce root-knot nematode populations. It works best applied before planting and repeated season on season, not as a one-off rescue.
Can neem cake be mixed with urea?
On conventional farms it is — neem cake slows the conversion of urea to nitrate, cutting nitrogen loss, which is why "neem-coated urea" exists. On a certified-organic farm you would skip the urea and use neem cake as a slow organic nitrogen source in its own right.
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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