Table 1.
Farm/year and treatment | Inorganic nitrogen,* kg⋅ha−1 | Carbon input,† t⋅ha−1 | Water index,‡ cm | Flood events§ | Intermittent flooding regime¶ | N2O, kg⋅ha−1 | CH4, kg⋅ha−1 | Yield, t⋅ha−1 |
Agroecological region# 3.0 (seed variety BPT 5204) | ||||||||
Farm 1 2012 | ||||||||
Baseline | 91 | 3.9–4.5 | −555 (85) | 1 | Medium | 13.1 (6.03) | 66.5 (38.4) | 4.8 |
Alternate | 0 | 4.1–4.8 | −580 (144) | 1 | Medium | 4.7 (1.53) | 81.1 (69.7) | 4.6 |
Farm 2 2013 | ||||||||
Baseline | 243 | 5.6–6.8 | −0.7 (33) | 3 | Mild | 0.62 (0.47) | 105 (7.23) | 4.8 |
Alternate | 0 | 8.4–10.0 | −152 (16) | 3 | Mild | 0.10 (0.20) | 98.3 (74.5) | 2.7 |
Agroecological Region# 8.3 (seed variety ADT 39) | ||||||||
Farm 3 2012‖ | ||||||||
Baseline | 219 | 0.0–0.0 | −486 (10) | 0 | Medium | 22.7 (7.47) | 3.98 (4.89) | 4.2 |
Alternate | 61 | 2.7–3.7 | −416 (81) | 0 | Medium | 2.51 (0.69) | 4.6 (0.39) | 2.7 |
Farm 3 2013 | ||||||||
Baseline | 202 | 0.6–0.8 | −1,036 (16) | 3 | Intense | 17.4 (15.4) | 108 (11.2) | 5.6 |
Alternate | 20 | 2.5–3.0 | −858 (52) | 3 | Intense | 11.5 (9.55) | 112 (33.9) | 4.0 |
Farm 4 2014 | ||||||||
Baseline | 174 | 1.0–1.2 | −212 (63) | 3 | Mild/medium | 0.88 (0.83) | 141 (19.3) | 3.5 |
Alternate | 91 | 1.1–1.4 | −316 (147) | 5 | Mild/medium | 0.02 (0.2) | 154 (54.3) | 3.2 |
Agroecological Region# 8.1 (seed variety ASD 16) | ||||||||
Farm 5 2013 | ||||||||
Baseline | 121 | 0.0–0.0 | 15 (65) | 3 | Mild | 1.39 (1.66) | 286 (49.1) | 6.5 |
Alternate | 99 | 0.01–0.02 | −155 (91) | 4 | Mild | 2.47 (1.16) | 216 (88.1) | 6.5 |
All errors in parentheses represent the ±95% confidence intervals (n = 3).
The ranges for mineralized organic nitrogen and emission factors for each replicate are presented in Dataset S1, Table 30.
Organic C content range as estimated via literature review (Dataset S1, Table 4–9).
Cumulative extent of flooding as determined by FWTs (SI Appendix, SI Text, section 3).
Number of times a replicate had flooding for >3 d.
SI Appendix, Fig. S1 presents our definitions of flooding regimes.
See SI Appendix, Fig. S2, for a regional map.
The methane flame ionization detector behaved anomalously in this cropping season, likely causing unusually low methane emissions.