Agricultural mechanization is a sine-qua-non to minimize drudgery, enhance timeliness and quality of farm operation and produce, improve working comfort besides optimizing the cost of production with higher productivity. Earlier, farmers relied upon muscle power and animate power for various farm operations. But with the passage of time, to meet the food and nutritional requirement of the burgeoning population, efficient farm equipment and devices have been introduced. A need has been felt for scientific testing and evaluation of farm power sources and machines to ensure better quality, reliability and safety based on relevant standards, test codes and safety guidelines. To explain above aspects of reliable testing and evaluation, a book was published in 1995. Based on the feedback from stakeholders and advancement of farm machinery sector, the book has been revised and updated with 20 chapters covering latest machines like rotavator, laser land leveller, zero-till drill, straw combine etc. It is hoped that it will serve the needs of scientists, professional engineers, tractor and agricultural equipment manufacturers, testing institutions, agricultural engineering colleges and staff working at different testing centres in India and abroad as a reference for standardization, quality assurance and further improvement.