Sesbania rostrata Brem. & Oberm. as green manure for transplanting and
direct seeding rice production methods in northeast Thailand saline soils
Sompon Waipanya
Kasetsart University, Bangkok 10900
.
Sesbania rostrata (stem-nodulating legume) was
grown as a green manure crop in the farmers field at Ban Tha-bo, Thawatchaburi
district, Roi Et province having saline sandy loam soil with pH of 4.8,
electric conductivity (EC) of 2.6 ds/m, organic matter (OM) of 0.32 %,
available phosphorous of 3.5 ppm (mg/kg) and soluble potassium of 0.85 me/l in
the 1990 early rainy season. At 60
days after sowing, S. rostrata plants were incorporated in the soil as
green manure before growing RD 15 and KDML 105 rice by direct seeding and
transplanting seedling in the 1990 rainy season.
The results indicated that across
the treatments of cultivation methods, S. rostrata as green
manure significantly increased rice yield from 398 (under no green manure) to
589 kilograms per rai, due to nitrogen accumulation of 26.2 kilograms per
rai. There was no significant
difference in rice yield between transplanting and direct seeding methods. S. rostrata increased the
transplanted rice yield by 238 kilogram per rai, while in the direct seeded
rice it increased yield by 145 kilograms per rai over planting rice without
green manure. The mean rice yield
of RD 15 was significantly higher than that of KDML 105 (514 and 473 kilogram
per rai, respectively).
African