Economy of small and marginal farmers heavily depends on agriculture and livestock. Integration of livestock with crop provide scope for effective utilization of byproducts which assures the profitability of the farming system. Integrated Farming System approach is an important tool to enhance the living standards of the small and marginal farmers. The book dealt with the findings of profitable crop - livestock based farming systems for arid regions, their diversification and sustainability. The economic sustainability of the faming systems was evolved through Sustainability Value Index (SVI). Diversification of farming systems was also evolved using the Simpson Index of Diversification (SID).The book is useful for academicians and students to conduct research work. The book also useful development agencies, agriculture departments, policymakers and also to small and marginal farmers to adopt sustainable farming systems in arid regions.