A cross-over experiment for on-farm evaluation of a novel pond aquaculture aeration device

On-farm experimentation is an essential part of aquacultural product development, but experimental designs that are commonly used for intensive commercial aquaculture are usually not suitable for earthen pond aquaculture, particularly in smallholder contexts. Guidance for on-farm testing of aeration technologies is similarly lacking. We therefore propose an experimental design (a cross-over experiment) that has not previously been applied to aeration in pond aquaculture, and we demonstrate its use as part of the field testing of a novel solar aeration device in Bangladesh. The cross-over experiment was less expensive than a large-scale randomized control trial, and we show that relying on randomization alone would have produced inaccurate results for this experiment. We analysed dissolved oxygen and fish growth rates using regression techniques, including multi-level regression and a generalized least-squares model with a lag-1 autocorrelation structure. We also describe the collaboration with a local farmer to build an experimental facility on his property, which was critical to the success of the experiment. The experiments showed that the device had a small impact on dissolved oxygen but was much less effective than commercially available products. On the other hand, the experimental design was effective and can be replicated to test other aeration technologies in on-farm conditions.