It is predicted that the world population will reach about 9.7 billion by the year 2050 and to feed this population the food production has to be increased proportionately. Further we are all concerned about climate which in turn results in abiotic stresses like drought, salinity, etc.These abiotic stresses will seriously affect crop productivity. This approach has gained popularity in the recent years and seems to be a potential option for the future.The present book brings out the role of different groups of microorganisms in alleviating abiotic stress in crop plants.