A bag is not a dose. How a nutrient is delivered is part of the product
2 fields can receive the same nutrient, in the same quantity and in the same season, and the crops can still respond differently. The form of the product, the timing and placement of the application, and the product’s physical fit with the application equipment decide how much of the nutrient reaches the crop. VAN therefore formulates each product for the application equipment as well as for the crop.
Pivot, drip and drone: what each irrigation or spraying system requires of the product
Each system places the nutrient differently. A centre pivot spreads it with the irrigation water over the whole circle, in many small doses. Drip irrigation delivers it to the wetted root zone. A drone delivers it to the leaf. By comparison, broadcasting spreads it over the whole soil surface, and the roots must reach it there.
| Pivot | Drip | Drone | |
|---|---|---|---|
| Where the nutrient lands | Whole circle, with the water | Wetted root zone only | On the leaf |
| Most demanding requirement | No precipitate in the carrier water | Near-zero insolubles, to protect emitters and filters | Concentration and suspension stability |
| Form VAN supplies | Soluble crystal and liquid | Liquid and soluble crystal, acidic reaction where water is hard | Concentrated liquid and fine water-dispersible granules (WDG) |
| What it gives the grower | Low-cost split application in many small doses | Precise placement, with nothing applied between the rows | Access and speed: it can spray crops that ground equipment cannot enter, and finish within a short spray window |
| Crops it suits best | Field crops under pivot irrigation | Orchards, high-value vegetables, protected cropping | Sugarcane, maize, rice and cotton, after the canopy closes |
In a centre pivot, the injected solution comes into contact with every part of a long galvanised span on each pass. It can damage the machine in 2 opposite ways: an acidic solution strips zinc from the galvanising, and an alkaline solution attacks aluminium. pH is therefore the main property to control in a pivot programme: the wrong pH makes the machine wear out sooner than normal. VAN sets the pH before the product is packed, rather than leaving it to the grower at the injection point.
The measured pH of each batch is on its lab report, which opens when the batch number is entered on the Verify a bag page. VAN has not run its own corrosion or equipment-life tests; the corrosion risks to a pivot are taken from standard corrosion engineering.
4 decisions that affect how much nutrient reaches the crop
Form
The form of a product affects how much of its nutrient stays available to the crop. On soil above pH 8, uncoated urea applied to the surface breaks down (hydrolyses), and part of its nitrogen is lost to the air as ammonia. Urea inside a sulfur coating dissolves gradually instead of all at once. In alkaline soil, chelated micronutrients stay available to the crop, while the sulfate forms of the same micronutrients precipitate and become unavailable.
Timing
A crop’s demand for nutrients peaks at defined growth stages, and much of the nutrient supplied outside those stages is wasted. VAN’s 28 crop plans are therefore written stage by stage rather than as a season total.
Placement
A nutrient can be broadcast, drilled, side-dressed, banded, applied through irrigation water (fertigation) or sprayed on the leaf. The ways in which nutrient is lost, and the amounts lost, differ from one method to another. Because the method usually depends on the equipment the grower owns rather than on agronomy, VAN designs each product for the method by which it will be applied.
Physical fit
A product that blocks an emitter, settles out of a spray tank or is too coarse for a drone boom cannot be used with that equipment, whatever its nutrient content. Solubility, particle size, pH and behaviour in a tank mix decide whether a product can be used with a given piece of equipment.
What each application method requires of the product
| Method | What it requires of the product | Where it is most useful |
|---|---|---|
| Broadcast and side-dressing | Granular integrity, controlled dissolution, resistance to volatilisation on hot alkaline surfaces | The bulk of field-crop nitrogen and base nutrition |
| Fertigation | Full water solubility, no precipitate, no emitter blockage, compatible pH | Orchards, high-value vegetables, any drip or sprinkler system |
| Foliar | Fine particle size, tank-mix stability, leaf-safe concentration, chelated micronutrients | Correcting a deficiency within days, without waiting for root uptake |
| Drone or ultra-low volume | High concentration in very little water, no nozzle blockage, stable in suspension | Tall or dense standing crops that a tractor cannot enter, and speed when the spray window is short |
| Seed and starter placement | Low salt index, safe in contact with germinating seed, phosphorus available to the young root straight away | Root establishment: a small amount placed close to the seed does more than a large amount spread widely |
VAN produces powder, granular, pellet, crystalline and liquid grades. When VAN develops a product to a client company’s brief, the client’s application equipment is part of that brief. Pack sizes are on each brand’s own page.
3 maize trials of Vital Urea, 2023 to 2025
Vital Urea has been used in 3 maize trials. In 2023, VAN and Rafhan Maize Products ran a trial jointly. In 2024, VAN and Descon ran a trial jointly at Descon Research Farm. In 2025, a partner company ran a commercial trial at Sheikhupura. In the 2023 and 2025 trials, 1 bag of Vital Urea (25 kg) took the place of 1 bag of urea (50 kg) at the first nitrogen application. Some crop plans use Vital Urea at more than 1 stage; follow your crop plan.
With Rafhan Maize Products
The Rafhan trial covered 5 grower sites at Khaliqabad, from application in August 2023 to harvest in December 2023.
The Rafhan trial was observational: it was not replicated or randomised. VAN publishes no yield figure from any of the 3 trials. Trial summaries are available on request to partner@van.com.pk.
One Tank: products formulated for the 20-litre tank of a spray drone
A spray drone carries about 20 litres and then has to land. Everything applied to the crop from 1 tank load has to be dissolved or suspended in those 20 litres. The mix must reach the leaf without blocking a nozzle, and it must be safe on the leaf at a concentration that the labels of ordinary products do not cover. A product for a drone tank therefore needs a different specification from a product for a knapsack sprayer. VAN gives products made to this specification their own name: One Tank.
A drone sprays whatever mix is put in its tank and does not correct it. When a drone application fails, the cause lies in a product grade that was not formulated for the tank rather than in the aircraft.
Why One Tank products have their own name
VAN does not add the word “drone” to an existing brand name. A drone version of a VAN product is a different formulation: it keeps the nutrient analysis of the registered grade but has a different particle specification, an added delivery package and a different dose per acre. If it carried the original product’s name, a grower might use one in place of the other. It is therefore given a name in a separate family, One Tank. The name refers to the 20 litres a drone tank holds.
VAN applies this naming rule without exception. Only a product designed from the start to be applied by drone is named in the One Tank family. A product with an existing VAN brand name stays outside the family, even if it has since been approved for drone use, and even if it dissolves well. SOP (sulfate of potash) is one such product: it is a soil and fertigation product, and VAN will not make a drone grade of it.
The One Tank family
| Code | Nutrient |
|---|---|
| One Tank K | Potassium |
| One Tank K+P | Potassium with phosphorus |
| One Tank N | Nitrogen |
| One Tank KN | Potassium with nitrogen |
| One Tank Zn | Zinc |
There are 5 codes, and each code names the nutrient. Crop-specific variants are also One Tank products: the crop is named on the pack, and the One Tank name does not change.
How the 20-litre tank limits the formulation
A One Tank application uses no more than 20 litres of total spray mix in the tank. VAN sets this limit before formulation work starts, and decides everything else within it, including concentration, solubility and which products can be mixed in the same tank. A grade that needs more water than the drone can carry cannot be used as a drone grade, even if it works well in a boom sprayer.
The 20-litre limit has 3 direct consequences. First, the nutrient has to dissolve and stay dissolved, or stay in suspension, at several times the concentration used in a knapsack sprayer. Second, the solution has to keep passing through the nozzle screen for the whole length of a flight, which rules out anything that settles or forms clumps (flocculates) in the tank. Third, it has to be safe on the leaf at that concentration, because the same quantity of nutrient lands in far less water.
VAN brands already applied by drone
6 VAN brands are approved for drone and ultra-low-volume spraying in their standard form: VL-Micromix, VL-Boron, V-Zinc, Tornado, V-Germinator Pro and Cala-Mag V. Dealers sell V-Germinator Pro for fertigation. Drone spraying of V-Germinator Pro is done only through VAN.
What VAN has decided so far for One Tank: the rate, the registration and the potash grade
The application rate for One Tank products is fixed at 1 litre of product per acre, mixed into a 20-litre tank of spray. VAN’s position on registration is also settled: a One Tank product is a formulation and grade variant of a VAN product that is already registered, so it is covered by that product’s registration and needs no separate licence. The potash grade is VL-Potash.
A One Tank product has the same nutrient analysis as the registered VAN grade it is built from. That analysis and the pack size are printed on the grade’s own page. A One Tank product adds a delivery package to that grade: ingredients that help it spray at ultra-low volume. It does not use a different nutrient raw material. VAN is still developing the delivery package through its own drone work. No figure for drift, coverage or spray efficiency exists yet.