Primary data were collected by means of field observations and
interviews with farmers; data refer to the two cropping seasons of
2010, including dry and wet seasons. Table 1 shows the precipitation
conditions that prevailed during these seasons compared to
long-term averages; it highlights the fact that 2010 received more
precipitation than 30-year averages, on both a yearly basis and a
per-season basis. Thirty farm plots were selected and studied for
wet-season rain-fed and irrigated rice systems (15 plots each) and
13 farm plots for dry-season irrigated rice system, based upon local
experts’ recommendations. Sampling was both purposive and
random, since farms were selected randomly among a large number
of farms identified by local experts within the three main
known cropping systems. Therefore, the selected farms are deemed
to represent the common farming situations found in Sam Lieo Yai
basin. Sub sample sizes ultimately differ (15, 15, 13, respectively)
owing to data quality issues in some farms, which had to be ultimately
discarded from analysis. Both environmental impact analysis
and techno-economic analysis were performed on all 43
cropping systems.