Soil Analysis

Soil pH is a measure of acidity or alkalinity. The lower the pH the more acid the soil. Soil pH's range from around pH 4 (very acid) when most crops will fail to pH of around 8 for soils which are either naturally rich in lime or which have been over limed.

There may be reasons to exceed the pH, for example to lessen incidence of club root in brassicas, but in general aim to avoid very high or very low pHs i.e. above 7.0 and below 5.0.

Soil pH has an effect on the availability of nutrients.

Phosphates are less soluble at low pHs and so less available to the plant. As pHs decrease below 6.0 calcium, magnesium and molybdenum become increasingly unavailable to the plant.

At high pHs all trace elements with the exception of molybdenum are much less soluble and plant deficiencies can occur.

It should be noted that analysis for manganese in the soil is unreliable and soil application of manganese is not recommended. Foliar sprays of manganese sulphate will correct deficiencies.

If a crop has shown patchy ares where growth has been poor it is worth having these areas checked for pH seperately