Management of rice production systems to increase productivity

fatty acids or alcohols as hydrogen donor, and the transmethylation of acetic
acid or methyl alcohol by methane producing bacteria (Conrad, 1989).
Redox potential is cited as the most important measurable factor for
production of CH4 in soils. The redox potential of soil gradually decreases
after flooding due to a decreased activity of the oxidized phase and increase
activity of the reduced phase (Cicerone et al. 1988; Yagi et al., 1990). Low
redox potential (‐200mv) favors CH4 production. The highly anoxic conditions
in flooded rice soil support a large methanogenic bacterial population and
hence create a large supply of CH4 (Min et al, 1997; Dubey and Singh, 2001).
Methane gas evolution from the soil can be greatly reduced if a field
can be drained briefly or intermittently (Sass et al., 1992; Lindau et al. 1993;
Minami, 1997), as practiced in SRI water management system.
Research Objectives and Hypotheses
The research objectives are as follows:
1. To identify to best rice seedling age for transplanting
2. To find out if SRI management practice is superior to
conventional management practice
3. To find out if the current fertilizer recommended rate for The
Gambia, meets the nutrient demand of SRI production
4. To promote SRI management practices on‐farm
The research hypotheses are as follows:
1. Transplanting is best with younger seedlings
83