Table 4.
Summary of findings of meta-analyses of the association between different types of rice cultivation practices and agronomic outcomes.
| Study | Country | Comparison | Plot size (no. of replications) | Outcome | Relative percent difference (95% CI) |
|---|---|---|---|---|---|
| Water management techniques | |||||
| Hill and Cambournac (1941) | Portugal | 10 day wet, 7 day dry cycle* | 2000 m2 (4) | Rice yield | + 15.1 (+ 0.5, + 31.9) |
| Mutero et al. (2000) | Kenya | Flooded before TP1, drained during TP, flooded after TP | 750 m2 (4) | Rice yield | − 7.9 (− 18.0, + 3.3) |
| Mutero et al. (2000) | Kenya | Flooded before TP, drained during TP, alternately flooded and drained after TP | 750 m2 (4) | Rice yield | − 9.5 (− 21.3, + 4.0) |
| Krishnasamy et al. (2003) | India | 4 day wet, 3 day dry cycle* (rotational water supply) | Varying sizes (5) | Rice yield | + 3.9 (− 0.7, + 8.7) |
| Krishnasamy et al. (2003) | India | Irrigation to 5 cm one day after disappearance of ponded water in fields | Varying sizes (5) | Rice yield | − 0.2 (− 5.5, + 5,4) |
| Rajendran et al. (1995) | India | 2.5 cm depth maintained for the first 10–14 DAT2. Fields subsequently dried out and re-irrigated to 5 cm depth after all standing water had disappeared (3–5 day after irrigation stopped) | 162,000–223,000 m2 (2) | Rice yield | + 2.4 (− 8.1, + 14.1) |
| RE model for all studies | + 0.8 (− 3.8, + 5.7) | ||||
| Hill and Cambournac (1941) | Portugal | 10 day wet, 7 day dry cycle* | 2000 m2 (4) | Water use | − 18.5 (− 30.0, − 5.1) |
| Krishnasamy et al. (2003) | India | 4 day wet, 3 day dry cycle* (rotational water supply) | Varying sizes (5) | Water use | − 7.5 (− 10.5, − -4.5) |
| Krishnasamy et al. (2003) | India | Irrigation to 5 cm 1 day after disappearance of ponded water in fields | Varying sizes (5) | Water use | − 21.0 (− 23.8, − 18.0) |
| RE model for all studies | − 15.4 (− 24.0, − 5.7) | ||||
Significant values are in bold.
*Water is applied to the field so that it is wet for X days and left for X days to dry before being irrigated again.
1TP: Transplanting.
2DAT: Days after transplanting.