Reading the soil test

pH

Also called: acidity, water pH, 1:2.5 pH, pH 5.2

pH says how acid or alkaline the soil water is. It is not the name of a disease. On grain land, root tips go brown below about 5.5 and agricultural lime can be discussed. Most grain and vegetables are comfortable around 6.0–7.5. Tea stays about 4.5–6.0 and must not be pushed to neutral. This page does not hand you a bag count.

EC

Also called: electrical conductivity, salinity EC, mS/cm, µS/cm

EC measures how salty the soil water is. High EC stresses roots; it is not the same as drought.

Total soluble salt

Total salt is the pile. Salty and soapy are different jobs.

Organic matter

Also called: organic matter, organic carbon, OM

Organic matter is the soil’s reserve and buffer, not the name of a microbial product.

Texture

Texture is the skeleton you were given. Management only changes structure.

CEC

CEC is how many nutrient seats the soil has. Low CEC needs smaller, more frequent dressings.

Aggregation

Crumbs are soil structure. Fertiliser will not pinch them into being overnight.

Porosity

Porosity is the pore space. You change it with structure, not in-season nitrogen.

Field capacity

Field capacity is how much water stays after drainage. Irrigating past it waterlogs the root.

Nitrogen (N)

Nitrogen builds leaves. The word is N; the field job is leaf position.

Available N

Also called: alkaline-hydrolysable N, available N, hydrolysable nitrogen

Available nitrogen on the sheet is this season’s supply, not a prescription.

Phosphorus (P)

Phosphorus is roots and flowering. The word is P; the field job is purple seedlings and pH.

Available P

Available P is what the root meets, not the purity on a bag.

Potassium (K)

Potassium runs water use and quality. The word is K; split scorch from white crust first.

Available K

Available K is this this season’s available nitrogen, not potassium in the rock.

Exchangeable Ca

Exchangeable Ca is the brick the soil can hand over. A foliar spray is only a rescue.

Exchangeable Mg

Exchangeable Mg is what the soil can hand over. A lab number, not a foliar brand.

Available Fe

Available Fe is iron the root can eat. Dumping ferrous sulphate on high-pH soil often fails this season.

Available Mn

Available Mn is manganese on new leaves. A lab number — fix extreme pH first.

Available Zn

Available Zn is a small door. Soil zinc is measured in years, not every trip.

Available B

Available B is a narrow window. Don’t broadcast it without a test.

Available S

Available S is sulphur the crop can use now. Urea itself has none.

Available Cu

Available Cu is copper for flowers and ears. Don’t dump it without a test.

Available Mo

Available Mo is a trace among traces. Doubling hurts.

Available silicon

Also called: available Si, available silica

Available Si is what the root can touch. Grasses care more. Soft stems are a clue, not a spray that replaces the soil.

Exchangeable Al

Below about pH 5.5, aluminium dissolves and injures root tips: brown, bald, few white tips. Then the top stalls. Fix the acid, don’t chase nitrogen.

Exchangeable sodium

Also called: Ex-Na, exchangeable Na

Exchangeable sodium is how many seats Na occupies. White crust is salt; high Na is sodicity.

ESP / SAR

Also called: exchangeable sodium percentage, sodium adsorption ratio

ESP is exchangeable Na over CEC. SAR uses Na, Ca and Mg in water. Both are alkali readings, not salt readings.

Chloride

Also called: Cl-, water-soluble chloride

Chloride is a common anion in salt. Potato, tobacco and some fruit dislike it. It is not the name of a potassium gap.

Bulk density

Bulk density is how tight the soil is. A hoe that will not enter asks this before hunger.

Test-based fertiliser

Test-based fertiliser is a method, not a universal recipe.

Acidification

Acidification is the name of pH walking down. Rates live on the acid handbook page.

Saline-alkali

Saline-alkali is a family name. Split salt from alkali before you treat.

Compaction / plough pan

Compaction is a closed road. Subsoiling is roadwork, not this season’s fertiliser.

Gleying

Gleying is the complexion of soil that lives underwater. Drain first, then add fertiliser.

Replant trouble

Replant trouble is the name of growing the same family again. A microbe bag is not a rotation.