John Andreas Widtsoe demonstrates an immense knowledge of soil and farming conditions; much of the advice in this classic manual remains useful and relevant to this day. An excellent collection of knowledge is united in this guidebook, which commences by setting out the concept and core principles of dry farming. Much of the Earth is covered by land which receives only modest rainfall each year; coupled with a lack of an underground water source and/or water rights, many landowners found themselves having to grow crops with dry farming methods. Widtsoe was one such farmer, and his knowledge of the land's properties would prove decisive in his success. The properties and composition of the soil are crucial in deciding what crops to grow, making maximum use of limited water resources in an unirrigated plot by encouraging the soil's water retention, and sowing seeds with methods to maximize germination are all important aspects of running a dry farm.