An important strategy to counteract the rapid decline in environmental quality is to promote sustainable agriculture. Biofertilizers are major components of sustainable farming and biological nitrogen fixation (BNF) is a fascinating biological phenomenon that effectively supplements to chemical nitrogenous fertilizers. Biofertilizers manufactured in India are carrier based in general and suffer from short shelf life, poor quality, high contamination and low and unpredictable field performances. Therefore, it is necessary to develop alternative new formulation of inoculants and in this context liquid inoculants can play significant role. Although the potential of Azospirillum has been well documented and substantiated, the successful exploitation of this diazotroph is hampered by several factors. Hence the book deals about the development, standardization and evaluation of liquid inoculant or cyst based liquid formulation of Azospirillum and quality checking of liquid bioinoculants through molecular techniques.