Edaphic factors :

Suitable  soil environment is necessary for better germination , growth , development and yield of crops.  For this is is necessary to understand the physical , chemical and biological  environments of the soil.

a) Physical environment :

• Soil texture determines water and nutrient holding capacity , compressibility and thermal regime.
• Brown colour of the soil indicates high organic matter and fertility while red color shows good aeration and white indicates the presence of salts.

b) Soil chemical environment :

• pH affects the availability of nutrients by affecting the decomposition and solubility of the essential element.
• Cation exchange capacity (CEC) influences the capacity of the soil to hold the nutrients such as Ca , Mg , NH₄⁺ , etc and the quantity of a nutrient required to change its relative levels in the soil.

c) Soil biological environment :

• The activities of soil micro fauna provide life to the soil : the higher the activities of these microorganisms ( Rhizobium , Clostridium , Nitrobactor , etc.), the more productive the soil becomes .