Symbiotic Nitrogen Fixation in Tropical Food Grain Legumes: Current Status

Abstract

In tropical regions, nitrogen (N) deficiency is frequently one of the major factors limiting the yield of grain crops which makes the contribution of symbiotic nitrogen fixation (SNF) of great importance, especially when legumes are involved in the cropping systems. Despite extensive research in the area of SNF worldwide, our knowledge on this subject and on how the research efforts could be translated and used to improve the productivity of legumes in different agro-ecological regions is still not sufficient. For these reasons and also considering the impacts that fossil fuels have upon global warming, the role of SNF in the twenty-first century will certainly increase. In this chapter, some aspects of the current status of SNF research are discussed focusing mainly on the four most important tropical food grain legumes, soybean, common bean, cowpea, and groundnut.