This bulletin is a collection of abstracts of U.S. patents selected from those published in the first 11 volumes of Fertilizer Abstracts. It contains 1014 abstracts selected as the most pertinent U.S. patents for the fertilizer industry today. U.S. equivalents of previously issued foreign patents are included. Defensive publications issued by the U.S. patent office have not been included.

This bulletin is a collection of abstracts of patents granted to TVA on fertilizer technology and related topics over about 45 years. It contains 200 patent abstracts that have been divided into 13 major sections. Each section reflects the improved technology through this period of time. Abstracts of some of the patents issued to TVA since 1968 have already appeared in Fertilizer Abstracts, a journal published monthly since 1968. Inventor and subject indexes are provided in this bulletin.

Fertilizer technology in a changing world; Nitrogen production facilities in relation to present and future demand; conversion of ammonia tofertilizer materials; Chemical and physical properties of nitrogen materials and their sphere of usefulness; Phosphate resources and processing facilities; Chemistry and manufacture of superphosphates and phosphoric acid; Chemistry and technology of new phosphate materials; Patash resources in the united states in relation to world supplies; Production and processing of potassium materials; Resources and processing of materials carrying calcium, magnesium, and sulfur; Mechanics of mixed-fertilizer production; Physical and chemical problems in mixed-fertilizer production.