Fertiliser is your single biggest input cost in maize farming. It's also the input where the gap between good management and bad management shows up most directly in your yield.

Too little nitrogen at the wrong time, and your crop runs out of fuel during grain filling. Too much applied all at once, and a good rain washes it straight through the root zone before the plant can use it. Wrong timing on phosphorus, and your roots never develop the depth they need. Skip zinc, and your crop limps along at 15–40% below its potential without you even realising why.

Getting NPK management right in maize is not complicated — but it does require following a specific sequence. This guide lays it all out clearly, based on ICAR-IIMR recommendations and current agronomic research, so you can build a fertiliser programme that works for your farm.

Why Maize Is a Heavy Feeder

Before the schedule, it helps to understand why maize needs so much nutrition.

Maize is a heavy nutrient feeder — it withdraws huge amounts of nutrients from the soil for plant growth. Hybrid maize is highly responsive to nutrient consumption and has a slightly higher nutritional requirement than other cereals due to its high yield potential.

Consider what the crop is doing: from a seed weighing less than 1 gram, a maize plant builds a 2.5-metre-tall structure, develops 10–15 large leaves, produces a tassel with thousands of pollen grains, fills an ear with 400–600 kernels, and does all of this in 90–120 days. That's an enormous amount of biological construction work — and every bit of it runs on nutrients from your soil and your fertiliser bag.

A maize crop yielding 6 tonnes of grain per hectare takes up approximately:

• 150–180 kg of nitrogen (N)
• 60–80 kg of phosphorus (P₂O₅)
• 120–150 kg of potassium (K₂O)
• Plus significant quantities of zinc, sulphur, magnesium, and other micronutrients

Not all of this has to come from applied fertiliser — healthy soils with good organic matter supply a portion. But on most Indian maize fields, especially those under intensive cropping, the soil cannot supply enough on its own. Applied fertiliser fills the gap.

The ICAR-Recommended NPK Starting Point

In general, the balanced recommended dose of fertiliser for maize is 120:60:40 kg/ha of NPK.

But this is a national average — a starting point, not a one-size-fits-all prescription. The actual amount you need depends on:

• Your soil's existing nutrient levels (which a soil test tells you)
• Your target yield (higher yield targets need more nutrition)
• Your season (rabi needs different management than kharif)
• Whether you're growing field corn, sweet corn, or baby corn

Here's the general framework, and then we'll break down each nutrient in detail:

Nitrogen: The Most Critical Nutrient — and the Easiest to Waste

Nitrogen is the most yield-determining nutrient in maize, and also the one most easily lost from your soil before the plant can use it.

Why split nitrogen matters

Conventional practice of applying a large portion of nitrogen through surface broadcasting just after maize planting has led to decreased crop production and low nitrogen use efficiency in India, because nitrogen applied to soil is vulnerable to losses from volatilisation, denitrification, leaching, and runoff.

In simple terms: if you apply all your nitrogen at sowing and it rains heavily, a large portion washes below the root zone. If you apply it all and the soil is hot and dry, it volatilises (escapes as ammonia gas) before the plant can absorb it. Either way, you've paid for fertiliser that didn't feed your crop.

The solution is split application — applying nitrogen in two to four doses across the crop's growth cycle, matching supply to the plant's actual demand at each stage.

The nitrogen split schedule for kharif maize

Nitrogen should be applied in three or four splits — at sowing, knee-high stage, pre-tasselling, and silking stage. This ensures continuous nutrient supply through rapid vegetative growth.

Here's the practical schedule:

Dose 1 — Basal (at sowing): 25% of total N Apply alongside your phosphorus and potassium as a basal dose, placed 5–7 cm below and beside the seed row (not directly on the seed). This gives seedlings an immediate nitrogen source as roots develop.

Dose 2 — Knee-high stage (20–25 DAS): 30–35% of total N This is the most important top dressing. At the knee-high stage, the maize plant is actively building its root system, leaf area, and vegetative mass. Nitrogen supplied here directly determines how large the plant will be at tasselling — which determines how many kernels the ear can support.

Apply as side placement (alongside the row, 5–7 cm from the stem base, worked into the soil) rather than broadcasting. Side placement gets nitrogen into the root zone faster and reduces surface volatilisation losses. Earth up after application to cover and incorporate the fertiliser.

Dose 3 — Pre-tasselling (40–45 DAS): 25–30% of total N The plant is approaching its maximum nitrogen demand. Tassel development, silk emergence, and early cob growth are all happening in rapid succession. A nitrogen deficit at this stage directly reduces kernel number and size.

Dose 4 — Silking/early grain fill (55–60 DAS): 10–15% of total N (optional) Some agronomists recommend a fourth small dose at silking, particularly for rabi maize with high yield targets. For kharif maize under rain-fed conditions, this dose may not be practical due to waterlogging risk from irrigation and rain.

Kharif vs rabi nitrogen management

Nitrogen use efficiency is better in rabi than in kharif, mainly due to better water management and lower leaching losses.

In rabi season, you control every irrigation event. Nitrogen applied as a top dressing stays in the root zone longer because there's no monsoon rain to leach it. You can apply slightly larger individual doses with more confidence. Rabi maize yields higher partly because of this better nutrient capture.

In kharif, the principle of "little and often" applies even more strictly. Smaller, more frequent nitrogen doses beat large single applications in monsoon conditions.

Nano-urea: the emerging tool

IFFCO's nano-urea — a liquid formulation of nitrogen in nanoparticle form, applied as a foliar spray — has entered wide commercial availability in India. The combined application of 100% recommended NPK through conventional fertilisers supplemented by two foliar sprays of nano-urea resulted in significantly higher dry matter accumulation, comparable in performance to 75% RDF + nano-urea — suggesting nano-urea can compensate for a 25% reduction in soil-applied urea while maintaining or improving yield.

In practical terms: if you're already at the recommended NPK dose, two nano-urea foliar sprays (at V6 and V10 stages) may help push yield further. If your urea supply is limited or expensive, replacing 25% of your soil-applied urea with nano-urea spray is a validated option.

Phosphorus: Apply It All at Sowing

Unlike nitrogen, phosphorus does not leach easily through the soil. It binds to soil particles and stays available for weeks. This means you can — and should — apply your entire phosphorus dose at sowing as part of the basal application.

Apply a quarter of nitrogen and the total amount of phosphorus and potash before sowing.

Why phosphorus at sowing matters: Phosphorus drives root development. In the first 2–3 weeks after germination, when the young maize plant is establishing its root system, adequate phosphorus is critical. Roots that develop early and deeply can access water and nutrients from a larger soil volume for the rest of the season — which pays yield dividends at every subsequent growth stage.

Phosphorus-deficient maize shows as purple or reddish discolouration on the undersides of young leaves — caused by accumulation of anthocyanins when phosphorus is too low for normal sugar metabolism. If you see this in plants under 30 days old, phosphorus supply was insufficient at sowing.

Recommended phosphorus dose: 50–75 kg P₂O₅/ha (approximately 110–160 kg DAP/ha if DAP is your source, or 300–470 kg SSP/ha if using single superphosphate).

DAP vs SSP:

• DAP (18:46:0) provides both nitrogen and phosphorus in one product and is the most commonly used phosphorus source for Indian maize
• SSP (0:16:0 + 11% sulphur) is cheaper per unit P and also supplies sulphur — useful in sulphur-deficient soils. Use SSP if your soil test indicates sulphur deficiency.

Potassium: Often Overlooked, Always Important

Potassium doesn't get talked about as much as nitrogen or phosphorus in Indian maize farming — and this is a mistake.

Potassium drives three critical functions in the maize plant:

1. Stalk strength — potassium-adequate plants have thicker, stronger stalks that resist lodging and stalk rot
2. Water regulation — potassium controls stomatal opening and closing, directly affecting drought tolerance
3. Grain filling — potassium facilitates the transport of sugars from leaves to the developing grain, directly affecting kernel weight

Potassium-deficient maize shows as yellowing and scorching (browning) of the leaf margins, starting from the lower leaves and progressing upward. If you've seen this symptom and attributed it to drought, you may actually be looking at potassium deficiency — particularly on light-textured sandy soils that don't hold potassium well.

Apply the full potassium dose at sowing along with phosphorus as part of the basal dose.

Recommended dose: 40–60 kg K₂O/ha (approximately 65–100 kg MOP/ha)

For kharif maize under irrigated conditions in southern India: 25 kg K₂O/acre is the standard recommendation; for rainfed kharif: 20–25 kg K₂O/acre.

Zinc: The Micronutrient That Costs Least and Matters Most

Zinc is the most widespread micronutrient deficiency in Indian maize soils — and one of the most yield-limiting when it occurs.

Zinc deficiency is perhaps the most widespread micronutrient problem in maize, mostly on alkaline calcareous soils and soils with low organic matter content. Zinc deficiencies may be intensified by a high level of phosphorus supply from soil or fertiliser.

Visual symptoms of zinc deficiency in maize:

• White or pale yellow striping between veins on young leaves (interveinal chlorosis)
• The striping appears first on the youngest leaves, not the oldest (opposite to nitrogen deficiency)
• In severe cases, whole leaves turn pale and growth stops — this stage is called "white bud" and can cause near-total crop failure in young plants
• Shortened internodes, giving the plant a stocky, stunted appearance

Soil application: One example of a recommendation from India is to add 25 kg zinc sulphate (21% Zn) mixed with 25 kg soil along the row during last ploughing. A single corrective soil application of zinc sulphate lasts 3–5 years in most soils.

ICAR-IIMR recommends zinc sulphate at 25 kg/ha as part of the basal dose for maize seed production plots; the same recommendation applies to commercial hybrid maize fields on zinc-deficient soils.

Foliar spray as backup: If zinc deficiency symptoms appear on a standing crop after sowing, apply zinc sulphate 0.5% solution (5g per litre of water) as a foliar spray. Two sprays at 10–15 day intervals during the vegetative stage correct deficiency faster than waiting for soil-applied zinc to take effect.

Important interaction: High phosphorus applications can worsen zinc deficiency by competing for uptake at root surfaces. On high-phosphorus soils, zinc supplementation is even more important — don't skip it just because the soil has adequate phosphorus.

Sulphur and Magnesium: The Forgotten Secondary Nutrients

Most Indian maize fertiliser programmes cover N, P, K, and zinc. But two secondary nutrients are increasingly important on intensively farmed soils:

Sulphur: Sulphur deficiency shows as yellowing of the youngest leaves first (distinguishing it from nitrogen deficiency, which starts from older lower leaves). Sulphur supports protein synthesis and chlorophyll formation. It's commonly deficient on sandy soils and soils with low organic matter.

Apply 20–25 kg S/ha as gypsum (calcium sulphate) or bentonite sulphur at sowing, mixed with the basal NPK dose. If you're already using SSP as your phosphorus source, you're getting sulphur automatically (SSP contains 11% S).

Magnesium: Magnesium is the central atom in the chlorophyll molecule — it's what makes leaves green. Magnesium deficiency shows as interveinal yellowing of older lower leaves (stripes between veins, similar to zinc deficiency but starting from lower leaves). Apply 15–20 kg MgO/ha as magnesium sulphate (kieserite) at sowing on magnesium-deficient soils.

The Biofertiliser Layer: Free Nitrogen from the Air

Before or alongside your chemical fertiliser programme, biofertilisers can reduce your nitrogen requirement by 15–20% — essentially free nitrogen, if you use them correctly.

ICAR-IIMR recommends seed treatment with Azatobacter/Azospirillum with PSB and NPK consortia @ 200g each per acre as a seed treatment option for integrated nutrient management in maize.

• Azospirillum: A nitrogen-fixing bacterium that colonises maize roots and fixes atmospheric nitrogen directly in the root zone
• PSB (Phosphate Solubilising Bacteria): Releases locked-up phosphorus in the soil, making it available to the plant. Particularly valuable on soils with a history of heavy phosphorus application
• VAM (Vesicular Arbuscular Mycorrhizae): Fungal networks that extend the plant's effective root system, improving water and nutrient uptake — especially phosphorus

These are available from KVKs, ICAR centres, and some private agri-input dealers. Mix with seed just before sowing (don't mix biofertilisers with chemical fungicides at the same time — keep them separate in the treatment sequence).

State-Wise Fertiliser Adjustments

While the 120:60:40 general recommendation is a good starting point, state agriculture departments publish crop and soil-specific recommendations that often differ:

ICAR's 2025 Kharif Agro-Advisory specifies: rainfed maize should receive 8 kg N + 20 kg P₂O₅ + 10 kg K₂O per acre; irrigated maize should receive 25 kg N + 50 kg P₂O₅ + 25 kg K₂O per acre at the basal dose.

Always check your state agriculture department's latest recommendations for your specific district — soil variability means even within a state, recommendations can differ significantly between districts.

The Integrated Nutrient Management Approach

The best fertiliser programme combines organic and inorganic inputs:

The available amount of farmyard manure should be applied before sowing, as a combination of organic manure and inorganic fertiliser gives better results than applying chemical fertiliser alone.

Here's the integrated sequence:

4–6 weeks before sowing:

• Apply well-decomposed FYM @ 6–10 tonnes/acre, incorporated during deep ploughing

At last harrowing (1–2 weeks before sowing):

• Apply zinc sulphate @ 10 kg/acre if soil is zinc-deficient
• Apply gypsum or sulphur if sulphur-deficient

At sowing (basal dose):

• DAP @ 50 kg/acre (provides N and P)
• MOP @ 20 kg/acre (provides K)
• Azospirillum + PSB seed treatment

At 20–25 DAS (knee-high):

• Urea @ 50 kg/acre (top dressing)
• Earth up after application

At 40–45 DAS (pre-tasselling):

• Urea @ 25 kg/acre (top dressing)
• Optional: Magnesium sulphate @ 5 kg/acre as foliar if Mg deficiency visible

At 55–60 DAS (silking) — optional:

• Urea @ 15 kg/acre for high-yield target fields only
• Nano-urea foliar spray as alternative to soil-applied dose

Deficiency Identification: What Your Crop Is Telling You

Plants communicate nutrient stress through visual symptoms. Learning to read them saves you from applying the wrong corrective treatment:

When you identify a deficiency after sowing, the fastest rescue is always a foliar spray — nutrients absorbed through the leaf reach the plant within 24–48 hours, versus soil-applied nutrients which may take several days to weeks depending on moisture and root activity.

The Single Most Common Fertiliser Mistake in Indian Maize Farming

Broadcasting urea on the soil surface without incorporation.

When urea sits on the soil surface in warm, moist conditions — which describes most kharif maize fields — it begins to decompose rapidly via urease enzyme activity, releasing nitrogen as ammonia gas. Studies show that surface-broadcast urea on bare soil can lose 20–40% of applied nitrogen to volatilisation within 3–5 days.

The fix is simple:

• Apply urea as side placement (not surface broadcast) — dig a narrow furrow alongside the plant row, apply urea, cover with soil
• Or apply just before an irrigation event or light rain — moisture moves the urea into the soil quickly before volatilisation losses accumulate
• Or use a urease inhibitor (NBPT-coated urea, available commercially as "Breathe-Easy" or "Smart Urea") which slows the decomposition reaction and reduces volatilisation losses by 30–50%

This single change — from surface broadcast to side-placed urea — can recover the equivalent of 15–20 kg of applied nitrogen per acre at no additional cost. It's the highest-return practice change available in maize fertiliser management.

Final Thoughts

Fertiliser management in maize is not about buying more inputs — it's about using the right inputs at the right time in the right place.

The ICAR-recommended 120:60:40 NPK framework is your starting point. Soil test results customise it for your field. Split nitrogen timing maximises your return on every bag of urea. Zinc sulphate at sowing prevents a deficiency that cuts yield by 15–40% without visible warning until it's already happened. And the combination of organic + inorganic + biological nutrition builds soil health season by season, so your next crop starts from a better base than your last.

Done right, maize fertiliser management is one of the most financially rewarding agronomic decisions you make. Every rupee invested in correctly timed, properly placed fertiliser returns many rupees in grain.

At CornIndia, we help farmers design nutrient management programmes for their specific soils, seasons, and yield targets. If you'd like help interpreting a soil test or building a fertiliser schedule for your farm, get in touch.

Related reads on CornIndia: Soil Preparation for Maize: Getting the Basics Right | Drip Irrigation for Maize: Water Savings and Yield Gains | How to Identify and Manage Fall Armyworm in Maize