Most Indian growers test their soil. Far fewer test their irrigation water, and on a drip-irrigated farm the water matters more.
Soil is tested once and changes slowly. Water passes through the root zone every day of the season, carrying whatever it holds. A borewell with high bicarbonate will undo a well-designed nutrition programme quietly, and the grower will spend the season blaming the fertilizer.
Four numbers on a water report decide most of it: pH, electrical conductivity, bicarbonate and chloride.
What to look at, and roughly where the trouble starts
| Parameter | Generally comfortable | Needs managing | Serious problem |
|---|---|---|---|
| pH | 6.0 to 7.0 | 7.0 to 8.0 | Above 8.0 |
| Electrical conductivity (dS/m) | Below 0.75 | 0.75 to 2.25 | Above 2.25 |
| Bicarbonate (meq/L) | Below 1.5 | 1.5 to 3.0 | Above 3.0 |
| Chloride (meq/L) | Below 2 | 2 to 4 | Above 4, and lower on sensitive crops |
Treat these as orientation rather than law. Crop tolerance varies widely, soil type buffers or worsens the effect, and a sandy soil behaves differently from a vertisol at the same water quality. A grape or citrus block should be judged more strictly on chloride than these bands suggest.
Bicarbonate is the one that catches people out
Bicarbonate does not damage the plant directly. It raises pH around the root, and pH does the damage.
Above about pH 7.5 in the root zone, iron, zinc and manganese convert into forms roots cannot take up, and phosphorus availability falls as it binds with calcium. So a grower applying zinc to a soil that tests deficient can see no response at all, conclude the product failed, and stop buying. The product was fine. The water neutralised it before the plant got there.
This is the mechanism behind a great deal of the zinc and boron deficiency measured across Indian soils not responding to correction. High bicarbonate is common in borewells across Maharashtra, Gujarat, Rajasthan and large parts of the south.
Bicarbonate also scales. It precipitates as carbonate inside drip lines and emitters, and blocked emitters produce dry patches that get blamed on the pump.
Two responses work. Acidify the water so bicarbonate is neutralised before it reaches the root, and choose fertilizers that run acidic in solution rather than adding to the problem. The Dragon Paste line is acidic in solution for exactly this reason, and Dragon Corrector addresses the water and soil directly where correction is needed on its own terms.
Salinity builds where the wetted zone is small
Electrical conductivity measures total dissolved salts. It matters under drip more than under flood, which is the opposite of what most growers assume.
Flood irrigation wets the whole field and pushes salts down and out. Drip wets a small volume and concentrates salts at the edge of it, precisely where the feeder roots sit. Every irrigation adds a little more, and without heavy rain there is nothing to remove it.
The effect is slow, which is what makes it dangerous. Yield drifts down over three or four years and gets attributed to the rootstock, the variety, or the weather.
Where the water is already saline, the correct response is to stop adding avoidable salt. Muriate of potash is roughly half chloride by weight, and chloride is a salt most crops do not need in quantity. Removing it from the programme is the cheapest salinity management available. Every product in the Dragon Ferti range is free of chloride, sodium and heavy metals.
Where the crop is already carrying salinity stress, Dragon Fighter supports it through the period, and Dragon Sea is built around seaweed extract for stress recovery. Neither replaces fixing the water.
Chloride is a crop-specific threshold
General salinity guidance understates the problem on sensitive crops, because chloride is toxic to some species at concentrations that would not trouble others.
Grape, citrus, potato, onion and many stone fruits are chloride sensitive. On those crops, water at 3 meq/L chloride combined with a chloride-based potassium programme is a compounding problem, not two separate ones.
The commercial consequences show up in specific places. On table grapes for export, vigour and berry size decline in the third or fourth year. On potato grown for processing, chloride depresses tuber dry matter, which is the metric the processor actually pays on. On onion, the root system is shallow so the concentration builds faster.
Hardness, iron and the emitter problem
Two more numbers are worth having on the report even though they are not plant nutrition questions.
Hard water carrying high calcium and magnesium will scale emitters, especially in combination with phosphate fertilizers, which can precipitate as calcium phosphate inside the line. This is a mixing-order and compatibility issue as much as a water issue. Where phosphorus and calcium are both needed, Dragon PhoCal is formulated to hold both without the precipitate risk of combining them separately.
Dissolved iron oxidises on contact with air and deposits inside the system as a reddish sludge that blocks emitters and feeds bacterial growth. Filtration and periodic line flushing handle it. Fertilizer choice does not.
Practical sequence
Test the water before designing the programme, not after the first problem. A basic irrigation water analysis costs very little against a season.
Test at the end of the dry season as well as at the start, because borewell chemistry changes as the water table drops, and the worst readings usually coincide with the period of highest crop demand.
Measure EC in the root zone through the season rather than only in the tank. The tank tells you what you added. The root zone tells you what stayed.
And read the fertilizer label for what is not in the analysis. Two products with the same three numbers can carry very different chloride, sodium and heavy metal loads, which is covered in more detail in the guide to what the numbers on a water-soluble fertilizer sack mean.
What this means for a dealer
Water testing is the best free consultation a fertilizer dealer can offer.
It costs almost nothing, it produces a document the farmer keeps, and it reframes the conversation from price to diagnosis. A dealer who explains why the grower’s zinc application did nothing, and can point at the bicarbonate figure to prove it, is in a completely different position from one competing on rate per bag.
It also protects the dealer. When a product underperforms because of water chemistry nobody tested, the product gets blamed. A water report on file prevents that argument.
Dragon Ferti supplies importers and distributors with Certificates of Analysis, Technical Data Sheets, Safety Data Sheets, full composition labels and Free Sale Certificates, and manufactures under ISO 9001, ISO 14001 and ISO 45001 certified management systems. The import and registration process covers what a distributor needs to plan for.
Conclusion
On a drip-irrigated farm the irrigation water is a daily input and deserves the same scrutiny as the fertilizer. Bicarbonate raises root zone pH and blocks micronutrient uptake, salinity concentrates at the edge of a small wetted volume, and chloride does specific damage to specific crops. All three are measurable before the season starts. For specifications, registration support or distribution enquiries, see the Dragon Ferti range, read grower reports on the testimonials page, or contact the export team through the contact page.
Frequently asked questions
What bicarbonate level in irrigation water causes problems?
Trouble generally begins somewhere above 1.5 meq/L and becomes serious above 3 meq/L, though soil type and crop tolerance shift the threshold. The effect is indirect: bicarbonate raises pH around the root, and the raised pH blocks iron, zinc and manganese uptake and reduces phosphorus availability.
Why did my zinc application produce no response?
The most common reason on Indian farms is high pH in the root zone, usually driven by bicarbonate in the irrigation water. Above roughly pH 7.5 the applied zinc converts to forms roots cannot take up. Acidifying the water, or applying zinc as a foliar spray which bypasses soil chemistry, generally solves it.
Does drip irrigation increase salinity risk?
Yes, relative to flood irrigation. Drip wets a small volume, so dissolved salts concentrate at the edge of that volume where feeder roots sit, and there is no large flush to remove them. The effect accumulates slowly across seasons, which is why it is often mistaken for varietal decline.
How often should irrigation water be tested?
At minimum before designing a season’s nutrition programme, and ideally again late in the dry season. Borewell chemistry shifts as the water table falls, and the poorest quality often coincides with the period of highest crop demand.
Can fertilizer choice compensate for poor water quality?
Partly. A fertilizer that runs acidic in solution works against high bicarbonate rather than adding to it, and removing chloride-based potassium removes a large avoidable salt load. Neither substitutes for treating the water itself where the readings are severe.