Urea vs DAP vs NPK Fertiliser: Which One Does Your Field Actually Need?

Urea is a straight nitrogen fertiliser and nothing else. It carries about 46% nitrogen by weight — the highest concentration of any solid nitrogen fertiliser in common use, which is exactly why it dominates Indian fertiliser consumption, since you carry less weight to the field for the same nitrogen. It supplies no phosphorus, no potassium, no sulphur and no micronutrients. If your crop's problem is anything other than nitrogen hunger, urea will not fix it, no matter how much of it you apply.

DAP — di-ammonium phosphate — is mainly a phosphorus fertiliser with a useful side of nitrogen. The standard grade carries about 18% nitrogen and about 46% phosphorus (printed on the bag as P₂O₅), which makes it the most common basal or 'at-sowing' fertiliser in India. The nitrogen in DAP is real and it matters at sowing, when a young root system needs a starter dose, but there is nowhere near enough of it to carry a crop through its whole season's nitrogen demand. DAP supplies no potassium and no sulphur.

NPK complex fertilisers are a different animal: nitrogen, phosphorus and potassium chemically combined into a single granule at a labelled ratio. India sells many grades — 10:26:26, 12:32:16, 20:20:0:13, 15:15:15, 19:19:19 and others — and those numbers are the percentage of each nutrient by weight, always in the order N : P₂O₅ : K₂O, with sulphur as a fourth number when the grade carries it. Because every single granule contains all three nutrients, a complex spreads far more uniformly across a field than the same nutrients would if you physically mixed separate bags of straight fertilisers together.

The number that matters is not the weight of the bag, it is the weight of nutrient inside it. The arithmetic is simple: kilograms of material × nutrient percentage ÷ 100 = kilograms of that nutrient. A 45 kg bag of urea (India's standard urea bag size, though it has changed over the years, so check the weight printed on the bag you are actually buying) at 46% nitrogen carries roughly 21 kg of actual nitrogen. A 50 kg bag of DAP carries about 9 kg of nitrogen and about 23 kg of P₂O₅. A 50 kg bag of 10:26:26 carries 5 kg of nitrogen, 13 kg of P₂O₅ and 13 kg of K₂O. Once you can run that calculation standing at the shop counter, you stop comparing bags and start comparing nutrients — which is the only comparison that means anything.

One more label quirk trips up a great many farmers: fertiliser bags state phosphorus as P₂O₅ and potassium as K₂O, not as elemental P and K. These are not the same numbers — for the same actual quantity of nutrient, the oxide figure is the larger one. So when you hold your soil test report up next to a fertiliser bag, check which form the report is using before you compare the two, or you will over-buy or under-buy without ever realising why.

Every one of the choices above turns on a single piece of information that most farmers simply do not have: what their soil is actually short of. A field that has received DAP at sowing every season for fifteen years is quite often sitting on a phosphorus surplus, and one more bag of DAP on that field is money burnt. A field that has never seen potash may be quietly capping its own yield no matter how much urea goes onto it. You cannot see any of this by looking at the soil, and you cannot infer it from what your neighbour is doing on land half a kilometre away.

A soil test is the cheapest input on the farm relative to what it saves, and it turns fertiliser buying from a guess into a calculation. Our guides Why Soil Testing Is Important: The Smartest Decision a Farmer Can Make and Soil Testing for Farmers: Why It Matters and How to Do It cover how to draw a proper sample, where to get it tested, and how to read the report that comes back. Get that report first, and the urea-versus-DAP-versus-complex question largely answers itself.

Government support for soil testing does exist, in the form of the Soil Health Card programme. But the sampling cycle, the fee where any applies, and the laboratories involved are administered at the state level and revised from time to time, so ask at your local Krishi Vigyan Kendra or district agriculture office for the current arrangement in your own area rather than relying on any figure quoted online, including in this article.

At sowing, the crop needs phosphorus already in place before the roots go looking for it, plus a modest amount of nitrogen to get started. That is the classic case for DAP or a phosphorus-carrying complex as a basal dose, banded a few centimetres to the side of and below the seed. Broadcasting phosphorus across the surface and mixing it into the top layer is far less efficient, because phosphorus binds tightly to soil particles and stays roughly where it lands — in alkaline calcareous soils it gets locked up as calcium phosphates, and in acid soils by iron and aluminium oxides. Placement is not a refinement here; it is most of the value you are paying for.

Once the crop is standing and growing, nitrogen is what it burns through fastest, and urea is the cheapest and most concentrated way to deliver it. Split top-dressings are almost always better than one large dose, because nitrogen applied all at once either leaches down past the root zone or pushes a growth flush the plant cannot support. Apply urea before an irrigation or into moist soil, and incorporate it where you can, so the nitrogen moves down into the soil instead of escaping to the air as ammonia gas.

Where the crop is sulphur-hungry — mustard, groundnut, soybean and most pulses are — DAP is a poor phosphorus choice, because it carries no sulphur whatsoever. Single super phosphate (SSP), at about 16% P₂O₅ plus roughly 11% sulphur and a useful amount of calcium, or a sulphur-bearing complex such as 20:20:0:13, often serves those crops better even though the phosphorus concentration is lower and you carry more bags. Similarly, if the one thing your soil test flags is potassium, neither urea nor DAP touches it — muriate of potash (MOP, about 60% K₂O) is the straight fertiliser for that job.

Excess urea is the single most common and most expensive fertiliser mistake in Indian farming, and it does not look like a mistake while it is happening — the crop goes dark green, grows fast and tall, and looks magnificent. What is actually happening is that the plant is building soft, water-filled tissue with thin cell walls on long, weak stems. In wheat and paddy that means lodging: the crop flattens under wind or heavy rain at exactly the point when the grain is filling, and a flattened crop is hard to harvest and loses yield outright. In cotton it means rank vegetative growth and delayed boll setting.

That same soft, nitrogen-rich tissue is also precisely what sucking pests and fungal diseases prefer. Heavy nitrogen reliably raises pressure from aphids, jassids and whitefly, from brown planthopper in paddy, and from fungal diseases including rice blast and powdery mildew — and a dense, over-fed canopy traps humidity, which compounds the problem further. So an over-application of urea often shows up a few weeks later as a pesticide bill and a fungicide bill, not merely as a lodged crop.

The second big mistake is imbalance. Because nitrogen from urea has long been the cheapest nutrient per kilogram in India, national nitrogen use has for decades run ahead of phosphorus and potassium use. A widely cited broad reference for balanced N : P₂O₅ : K₂O use is around 4:2:1, and all-India consumption has generally been more nitrogen-heavy than that, with the exact ratio shifting from year to year as prices and policy change. The practical consequence on a single farm is straightforward: once nitrogen stops being the limiting nutrient, more urea adds cost and risk without adding yield, because something else — phosphorus, potassium, sulphur, zinc — has become the ceiling.

Two smaller but easily avoided errors round out the list: broadcasting urea onto a dry soil surface or into standing water and simply leaving it there, which loses a meaningful share of the nitrogen to the air as ammonia; and applying DAP as a late top-dressing, where the phosphorus has almost no chance of reaching the roots that actually needed it back at sowing.

A bag of urea and a bag of DAP are not comparable purchases, so comparing their prices tells you nothing useful. The figure to work out is cost per kilogram of the nutrient you are actually buying: bag price ÷ kilograms of that nutrient in the bag. Do this at your own shop with today's prices, for each of the two or three ways you could supply a given nutrient — phosphorus from DAP versus phosphorus from SSP versus phosphorus from a complex, for example — and the cheapest route quite often turns out not to be the one you assumed.

Fertiliser pricing in India is also not a free market, and that matters for this comparison. Urea's retail price is government-controlled, and different fertilisers attract different levels of subsidy support, which is precisely why nitrogen has historically been the cheapest nutrient at the counter and why over-application of urea became so widespread. We are intentionally not quoting any prices or subsidy figures here, because controlled prices, nutrient-based subsidy rates and their applicability are set and revised from time to time by government notification. Check today's actual rates at your own dealer before doing the arithmetic.

Between them, urea, DAP and standard NPK complexes cover nitrogen, phosphorus and potassium, and that is genuinely most of what a crop removes from the soil. But they leave real gaps. Sulphur is absent from urea, from DAP, and from many complex grades, and sulphur deficiency is common in oilseeds and pulses. Micronutrients are absent from all of them unless you specifically buy a fortified grade — zinc deficiency in particular is widespread in the rice-wheat belt, showing up as stunted plants with pale bands along the leaves, and no quantity of NPK will correct it.

The biggest gap of all is organic matter. None of these fertilisers adds a single gram of organic carbon to your soil, and organic carbon is what holds water, feeds soil life, keeps the soil loose enough for roots to work through, and stops the nutrients you have paid for from washing straight out of the root zone. Chemical fertiliser tops up nutrients precisely; organic matter builds the soil that makes those nutrients usable in the first place. Our guide Organic Manure vs Chemical Fertiliser: What's Best for Your Farm covers how to run the two together instead of choosing between them.

The short version: get a soil test, then read labels instead of brand names. Use a phosphorus source — DAP, SSP or a matching complex — as a basal dose placed near the seed at sowing, chosen according to whether your crop also needs sulphur. Use urea as split top-dressings through the season to cover the crop's nitrogen demand, applied into moist soil rather than broadcast onto a dry surface. Use a complex when more than one nutrient is short and some grade roughly matches the shortfall, and straights when you need to dial one nutrient in precisely. Add potash separately if the test asks for it, sulphur and zinc if the crop or soil asks for them, and organic matter every season regardless.

And treat every quantity in this article as general guidance only. This post is about which fertiliser supplies what, and when each is the sensible buy — it is deliberately not a dosage chart. The actual dose for your field is whatever your own soil test result and your local agriculture department or Krishi Vigyan Kendra recommend, for your crop, on your soil, in your district. No article can know that, and any article that hands you a confident number without seeing your soil test is guessing on your behalf.