TITLE:
Effects of puddling on percolation and rice yields in rainfed lowland paddy cultivation: Case study in Khammouane province, central Laos
AUTHORS:
Yoichi Fujihara, Ryuichi Yamada, Masato Oda, Hideto Fujii, Osamu Ito, Junichi Kashiwagi
KEYWORDS:
Rainfed Lowland Paddy; Rice; Puddling; Percolation; Yield; Laos
JOURNAL NAME:
Agricultural Sciences,
Vol.4 No.8,
August
9,
2013
ABSTRACT: We investigated the effects of
puddling on percolation and rice yields in rainfed lowland paddy cultivation.
We selected a study village in Khammouane province, central Laos, and set up
non-puddling and puddling plots from high to low positions. Even when puddling
was conducted carefully, the ponding water in the plots disappeared in the
case of little rainfall. Further, percolatifons during the later periods of rice
growth increased drastically. Therefore, it is difficult to overcome drought
stresses only by conducting puddling. We also compared the water conditions
in the non-puddling and puddling plots. In the puddling plots at high position
and low position along a stream, the number of days without ponding water in
the puddling plots was less than that in the non-puddling field in July, suggesting
the possibility of a different transplanting date. We tried to estimate the effects
of transplanting date on the rice yields and found that transplanting 15 days
earlier leads to an increase of 0.5 t/ha in the rice yields. Moreover, the
profits from the increased yields exceed the puddling costs considerably,
leading to a definite increase in income. Because the transplanting date
has no effects in the fields with high
ground water, puddling is effective in paddy fields where ponding does
not occur to a significant degree.