Description
CHAPTER ONE
1.0 INTRODUCTION
The population of the sub-sahara African and that of the world is increasing rapidly. Mannions
(1998) noted that every year the world population will increase by 1.6 to 1.7 percent, so every
year 90 million people are added to the consumers of agricultural products. This means that
food production must increase to improve the needs of the human diet (Nabizade et al., 2011).
Many researchers (Aoyama et al., 1999; Olayinka, 2009) have recommended the application of
organic manures to tropical soils as sources of nutrients because the soils tend to be inherently
low in soil organic matter (SOM), and low activity clays are predominant in the clay mineralogy
(Okusami et al., 1997). Application of farmyard manure to soil improved crop performance, soil
fertility, soil organic matter, microbiological activities and improved soil structure for
sustainable agriculture (Blair et al., 2005; Kundu et al., 2006). For healthy growth and optimal
yield, nutrients must be available to plants in correct quantity, proportion and in a usable form at
right time. To fulfill these requirements, inorganic fertilizers and organic manures are needed.
Reports have indicated the beneficial effects of this practice in terms of improved soil fertility
and balanced plant nutrition (Uyovbisere and Elemo, 2000; Ayoola and Agboola, 2002; Ayeni,
2008; Olayinka, 2009). The application of organic materials influence the degree of aggregation
and aggregate stability and can reduce bulk density, increase porosities, water holding capacity,
moisture retention and transmission, and drought resistance in plant (Cheng et al., 1998).