Laboratory work on chemical properties of

Soil acidity simply means how sour or alkaline your soil is. This matters because different crops grow better in different soil types. To measure this, we use a pH meter, which gives us a number between 0 and 14. Numbers below 7 mean acidic soil, 7 is neutral, and above 7 is alkaline. In Nigeria, many southern soils tend to be acidic due to high rainfall, while northern soils are often neutral or slightly alkaline.

When testing soil pH in the lab, you collect soil samples, mix them with distilled water, then insert your pH meter into the mixture. The meter shows the reading instantly. If you lack a pH meter, you can use simple indicators like litmus paper or even make natural indicators from red cabbage juice, though these are less precise.

Understanding soil pH helps Nigerian farmers know which crops suit their land. Cocoa, for instance, prefers acidic soils common in the south.

Chemical fertilizers are substances containing plant nutrients that dissolve in soil water to feed crops. The main types are nitrogenous, phosphatic, and potassic fertilizers, each with distinct chemical properties. Nitrogenous fertilizers like urea are highly soluble and quickly absorbed by plants. Phosphatic fertilizers such as single superphosphate dissolve slowly, making nutrients available over longer periods. Potassic fertilizers like muriate of potash are also water-soluble and mobile in soil.

In Nigeria, farmers commonly use NPK fertilizers—blended products containing nitrogen, phosphorus, and potassium in specific ratios like 15:15:15. These have intermediate solubility rates. When testing fertilizers in the laboratory, you can observe how quickly they dissolve in water and identify their pH levels, which affects soil acidity. Some fertilizers like lime-based products raise soil pH, while others lower it.