Table 4. Summary of findings of meta-analyses of the association between different types of rice cultivation practices and agronomic outcomes. Significant values are in bold.
| 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) | ||||
*
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.