SECTION B: REVISED EXPERIMENTAL DESIGNS

KENYA RESEARCH

Fish Yields and Economic Benefits of Tilapia/Clarias Polyculture in Fertilized Ponds
Receiving Commercial Feeds or Pelleted Agricultural By-Products

Feeds and Fertilizers Research 2 (9FFR2)/Experiment

Experimental Design Modification
The feeding regime featured the use of pig finisher pellets with regular fertilization rather than the use of poultry pellets. Fish were fed at a rate of 2% body weight per day rather than 3% body weight per day, and there was no progressive decrease in the daily feed ration as fish grew. Ponds were stocked at densities closer to 20,000 than 30,000 fish per hectare.

Effluents and Pollution Research 1 (9ER1)/Experiment

Experimental Design Modification
The original design called for the use of irrigation water combined with differing levels of fertilization with P. In the modified design, different water sources were used instead. The three water sources were canal water (with low P and low N), pond water (with 1 to 3 mg P l^-1 and 5 to 10 mg N l^-1), and a 50/50 mix of canal and pond water. This was done to match the ongoing global experiment. The irrigation rate was increased from 500 mm per treatment after the second planting cycle to counter evaporation.

The experiment was prolonged to a third planting, rather than a single repetition, to counter the effects of drought.

Kale replaced tomatoes as one of the crops grown because the survival rate of tomatoes rendered the first experiment a failure. Kale’s total biomass and edible portion are closely related; in addition it is widely consumed and easy to grow. Kale is not an export crop; thus, researchers grew one export crop (French beans) and one local consumption crop (kale).

The soil’s ability to strip P and N under flood irrigation conditions was evaluated by an add-on soil column test that formed the basis of an M.S. thesis.

Adoption/Diffusion Research 3 (9ADR3)/Activity

Experimental Design Modification
The training plan has been modified to include direct farmer training, using farmer field days as the chosen method, rather than training sessions for Fisheries Extension Officers alone. While the original plan called for training of 280 Fisheries Extension Officers, the new plan estimates that 300 officers and farmers will be trained. In addition, the number of training days has been altered. The original plan called for a total of 105 training days; the new plan calls for 250 training days. Finally, training locations have been changed to include only Sagana Fish Farm and the Cheploilel Campus of Moi University.