Soil Conditioners are defined as any material that contains limited amount of nutrients, but are managed primarily for their beneficial impact on the biological, physical or chemical nature of the soil. Soil needs conditioning for a number of reasons: to control soil degradation, to improve soil air-water relations, soil drainage and aggregation, to reduce soil crusting and compaction, to overcome water repellency. Any process which increases the ability of a soil to enhance crop yields, or which improves the performance of a soil function, can be described as soil conditioning, and any product used in soil conditioning is a soil conditioner.
The secondary plant nutrients are calcium, magnesium and sulphur which required by the plants in smaller quantities. The major roles of secondary nutrients are involved in cell wall, chlorophyll molecule formation, photosynthesis, nitrogen fixation and acts as a messenger when plants are physically or biochemically stressed. It also an activator for many enzymes required in plant growth processes and these secondary nutrients influence on physical, chemical and biological conditions respectively in soil.