Soil pH (acidity and alkalinity).

 

Soil pH (acidity and alkalinity) gives an important indication of plant nutrient availability, and different crops thrive at different pH values. Soil pHmay change in response to management activities such as liming, fertilizeraddition, irrigation that leads to salt accumulation, and some forms of soil pollution. Soil pH may be measured in the field with simple indicators, or with standard laboratory measurements. It is relatively cheap, quick, and easy to determine. Amending a low (acidic) pH can lead to greatly improved crop yields.