In spite of the relative homogeneity of cropping practices,
overall and per sub-cropping system, outcomes in both economic
and environmental terms show significant diversity. Net income
and global warming potential are particularly wide-ranging in the
different systems. This variation mostly results from large differences
in yields, overall and per sub-cropping system. Yields and
resulting net incomes are more diverse (less stable over time) in Rw
and Id systems compared to Iw systems, due to a lack of control of
the water supply and a lack of water, respectively. Attempts to
relate farmers’ performances to several socio-economic factors at
the household level (i.e., experience in farming, age, level of education)
proved unsuccessful. Instead, it was observed that, while Id
farmers usually try to refill their paddy fields three times per season,
many do not actually obtain enough water (e.g., canal tailenders).
The precipitation levels of the dry season of 2010 were
relatively high compared to 30-year average precipitation levels;
the lack of water for Id system farmers could have been even more
damaging to yields in normal or drier years. This would potentially
result in lower yields, and increased differences in performances
and impacts between wet season and dry season systems. The same
reasoning applies to Rw systems, which showed relatively high
performances and low impacts in 2010, but would perform well
below Iw systems under drier conditions.