Manure Storage & Nitrogen Retained vs Lost
Saves nitrogen
Estimate the nitrogen your manure keeps and loses as ammonia over storage — loss compounds each month, so covering, compacting and quick incorporation save N.
Manure nitrogen storage loss
Next: cover the heap, compact it, or store it on a sealed pad to slow losses; only 38.9 kg N of the original 50 kg survives to the field.
Most loss is ammonia volatilisation and leaching; covered or composted manure loses far less than an open, uncovered heap.
Manure storage N — key facts
- Lost as
- Ammonia gas
- Worst case
- Open heaps, hot weather
- Loss timing
- Compounds each month
- Cover
- Cuts surface ammonia escape
- Compact
- Excludes air, slows loss
- Incorporate
- Quickly after spreading
- Retained N
- True value at spreading
- Privacy
- Runs in your browser; nothing uploaded
The nitrogen you store is not the nitrogen you spread
Manure is a valuable, slow-release source of nitrogen — but a lot of it can vanish before it ever reaches a field. Nitrogen escapes from stored farmyard manure as ammonia, especially in open uncovered heaps in hot weather, and loss compounds each month, so covering, compacting and quick incorporation save N. A heap left exposed through a hot season can shed a large share of its nitrogen to the air.
This tool estimates the nitrogen retained and lost over the storage period, with the initial N, retained N, lost N and loss percentage. Use it to value your manure honestly, to see the payoff from covering and compacting, and to feed a realistic N figure into your fertiliser plan. Pair it with the FYM Fertilizer Equivalent and Compost & Manure calculators for the full picture.
Value manure honestly
Know the N you'll actually spread.
See the payoff
Covering and compacting keep nitrogen.
Cut ammonia loss
Incorporate quickly after spreading.
Plan fertiliser
Feed retained N into your budget.
Frequently Asked Questions
What does the manure storage nitrogen loss calculator do?+
It estimates how much of the nitrogen in your farmyard manure is retained and how much is lost as ammonia over the storage period. You enter the starting nitrogen and how long and how it is stored, and it returns initial N, retained N, lost N and the loss percentage — so you know the real N value at spreading.
Why does stored manure lose nitrogen?+
Nitrogen escapes from stored farmyard manure as ammonia, especially in open uncovered heaps in hot weather. Microbes break down the manure and release ammonia gas, which volatilises into the air. The more exposed the surface and the warmer and drier the conditions, the faster that nitrogen disappears.
How fast does the nitrogen disappear?+
Loss compounds each month, so the longer manure sits exposed, the smaller the share of nitrogen that survives. A heap stored a few weeks loses far less than one left through a hot season. The calculator reflects this so you can see why prompt use and good storage pay off.
How can I reduce nitrogen loss in storage?+
Covering, compacting and quick incorporation save N. Cover the heap to cut surface ammonia escape, compact it to exclude air, store it in a pit or on a sealed pad, and incorporate it into the soil soon after spreading rather than leaving it on the surface to volatilise further.
Does covering the heap really make a difference?+
Yes — a cover (sheeting, a soil cap or a roof) traps ammonia and shields the surface from sun and wind, sharply slowing volatilisation. Combined with compacting to keep air out, it can retain a large share of the nitrogen that an open, loose heap would otherwise lose.
Why does quick incorporation matter?+
Once manure is spread, ammonia keeps escaping from the surface until it is mixed into the soil. Incorporating within hours rather than days captures much more of the remaining nitrogen, so the field actually receives the N you stored rather than venting it to the air.
Does this only apply to cattle manure?+
The same ammonia-loss principle applies to most farmyard and animal manures and to compost heaps. Enter the relevant starting nitrogen for your material; the storage method, duration and weather drive the loss in the same way regardless of the animal source.
How does this change my fertiliser plan?+
Knowing the retained N tells you the true nutrient value of the manure you will spread, so you do not over-credit it and end up short. Feed the retained N figure into your nutrient budget and adjust bought-in fertiliser accordingly. Pair it with the FYM Fertilizer Equivalent calculator.
Are the figures precise?+
They are solid planning figures. Actual losses vary with temperature, rainfall, manure type, moisture, heap size and handling, so treat the result as a realistic estimate of storage losses, improve storage where you can, and re-check against your own observations.