When inorganic fertilizer and pig manure are
added to the trench of rice±fish fields, the SGR of
T. pectoralis increases significantly (Table 4). For
large rice fields converted to ponds in Central
Thailand, Yoonpundh & Little (1997) reported
better results when chicken and pig manure were
used. In these fertilized systems, farmers also give
supplementary feed (Yoonpundh & Little 1997),
consisting chiefly of mowed soft aquatic plants
applied as green manure (Hora & Pillay 1962; Huet
1972; Bardach et al. 1972; Indrambarya 1981;
Edwards 1987; Coche & Edwards 1989; Yoonpundh
& Little 1997) and detritus (Hora & Pillay 1962;
Huet 1972). In extensive rice culture systems in
Vietnam's Mekong Delta, farmers sometimes apply
ashes obtained after burning the rice stubble (Lazard
& Cacot 1997).