How to Read Your Soil Health Card: All 12 Parameters Explained in Plain Language

The soil health card reports twelve parameters, grouped in a way that becomes obvious once you know the logic. Three are the primary macronutrients — nitrogen, phosphorus and potassium. One is a secondary nutrient, sulphur. Five are micronutrients — zinc, iron, copper, manganese and boron. The remaining three are not nutrients at all but soil properties that govern whether the nutrients are available: pH, electrical conductivity and organic carbon.

Those last three matter most and get read least. You can apply a perfect fertiliser dose onto soil with the wrong pH and the plant will still not get it. Read the properties first, then the nutrients.

pH measures acidity and alkalinity. Most crops perform best in the roughly neutral band, around 6.5 to 7.5. Below that, in acidic soil, phosphorus gets locked up and aluminium can become toxic; the standard correction is lime. Above it, in alkaline soil — very common across large parts of Gujarat, Rajasthan and the Deccan — iron and zinc become unavailable, which is why crops show yellowing on new leaves even when the soil test says iron is adequate. Gypsum and organic matter are the usual corrections, alongside using chelated micronutrients that stay available at high pH.

EC, electrical conductivity, measures salinity. A high EC means salts are accumulating, usually from irrigation water quality or poor drainage, and salt-affected roots cannot draw water even when the field looks wet. If your EC is rising across successive cards, the problem is your water and drainage, not your fertiliser — and no amount of nutrient application will fix it.

Organic carbon is the single most important number on the card and the one most Indian soils fail. It is the measure of living, decomposed organic matter, which holds water, holds nutrients, feeds soil biology and gives soil its structure. A very large share of Indian fields test low. Raising it is slow — measured in years, not seasons — but it is also the change that makes every other input work better.

Nitrogen is almost always reported low, because it is mobile — it leaches with irrigation and volatilises into the air — and because most soils genuinely are deficient. This is why nitrogen is applied in split doses through the season rather than all at sowing: a single large basal dose largely washes away before the crop can use it.

Phosphorus is the opposite problem. It is immobile and accumulates, and many farmers who have applied DAP every season for years now test high or very high in phosphorus while still buying more of it. If your card shows high phosphorus, reducing or skipping the phosphatic fertiliser for a season is usually free money — this is the single most common saving a soil health card reveals. Note also that phosphorus availability is strongly pH-dependent, so a high reading in very acidic or very alkaline soil may still not reach the plant.

Potassium is often reported as adequate in Indian soils, and is often genuinely under-applied anyway for high-demand crops like banana, potato and sugarcane. It governs water regulation and disease resistance, and deficiency shows as scorching along leaf margins.

Sulphur deficiency has become widespread as farmers moved from older fertilisers that contained sulphur incidentally to concentrated formulations that do not. It matters especially for oilseeds — groundnut, mustard, sesame — where it directly affects oil content, and for pulses. Deficiency looks like nitrogen deficiency but appears on new leaves instead of old ones, which is the distinguishing test.

Among micronutrients, zinc is the most commonly deficient across India, particularly in rice and wheat systems, and iron deficiency is extremely common in alkaline soils. Boron matters disproportionately for fruit and seed set — deficiency shows up as poor filling rather than poor growth, so it is often missed entirely. Micronutrients are needed in very small quantities, which cuts both ways: a deficiency is cheap to correct, and an overdose is genuinely toxic. Never apply micronutrients by guesswork, and never exceed the recommended rate on the assumption that more is better.

The card gives crop-wise fertiliser recommendations, and the important thing to understand is that these are stated in terms of nutrients, not in terms of bags. If it recommends a quantity of nitrogen per hectare, you need to convert that into the actual product you buy — urea, DAP, MOP or a complex — accounting for the nutrient percentage each contains. Applying the recommended number as though it were bags of urea is a real and common error.

Check the unit as well. Recommendations are typically per hectare while most farmers think in acres, bigha or vigha. Getting this conversion wrong by a factor of two and a half is one of the most expensive arithmetic mistakes in Indian farming — our land unit converter handles bigha, vigha, guntha, acre and hectare so you do not have to guess.

Our guides on composting at home and on the farm and improving soil health naturally cover the practical steps, and organic manure vs chemical fertiliser explains how to combine both sensibly rather than treating it as a choice between them.

If you do not have a current card, apply through your taluka agriculture office or nearest soil testing laboratory; the scheme operates nationally and cards are issued in a periodic cycle. A card older than two years is worth refreshing, because organic carbon and pH shift with management.

The sample determines whether the report means anything. Take multiple sub-samples from across the field in a zigzag pattern, at plough depth, mix them thoroughly and take a composite from that mixture. Do not sample immediately after fertiliser application, near a bund, near a manure heap or in a waterlogged patch. Why soil testing is important covers correct sampling in detail — an unrepresentative sample produces a confidently wrong report, which is worse than no report at all.

Once you have the numbers, turn them into a season plan rather than a filed document. Khetiyaar's crop planning app converts a crop, an area and a sowing date into dated fertiliser and irrigation tasks, and the AI farming chatbot will explain any parameter on your card in Gujarati, Hindi or English if a line of it does not make sense.