CHAPTER ONE
INTRODUCTION
1.1Â Â Â Â Â Background of the Study
Soybean (Glycine max) is relatively new crop in Africa. Until recently, it was seen as being appropriate only for large- scale commercial farming for production of seed that are used in making livestock feed. The major soybean producing countries in the world are the United States, Brazil, China, Nigeria, India, Argentina, South Africa and Uganda (IITA, 2009).Soyabean cultivation in Nigeria starts in May / June with land clearing, and its harvesting normally done in October through November. The crop is harvested 3-4 months after planting, depending on the time of sowing and the variety. Benue state is the dominant soybean producing area but several other states, such as Kaduna, Plateau, Nasarawa are increasing in production. Soybean can contribute to the enhanced sustainability of intensified cropping systems by improving soil fertility through nitrogen fixation, permitting a longer duration of ground cover in the cropping sequence, and providing useful crop residue for animal feed (Rolling and Wagemater,
1998).
Over the last two decades, International Institute for Tropical Agriculture (IITA) has made substantial effort to improve the productivity of the crop by developing high yielding, early maturing varieties capable of nodulating in association with the local rhizobia, and possessing and other good agronomic traits.
