Advances in Agronomy

Volume 73 contains 4 reviews on contemporary and important topics in the agronomic sciences. In Chapter 1, "e;Interactions among Root-Inhabiting Fungi and Their Implications for Biological Control of Root Pathogens,"e; fungi are defined, their distribution and abundance are discussed, and their role in agroecosystems is present. Chapter 2, "e;Dwarfing Genes in Plant Improvement,"e; discusses advances in the role of dwarfing genes in plant improvement. Emphasis is placed on breeding and genetic aspects. Chapter 3, "e;A Review of the Effect of N Fertilizer Type on Gaseous Emissions,"e; covers a topic that is of great environmental interest - the effect of nitrogen fertilizers on gaseous emissions. Chapter 4, "e;Rhizobia in the Field,"e; is a comprehensive review of rhizobia including diversity, systematics, natural populations, and field introduction of rhizobia.