Influence of Gypsum Amendment on Methane Emission from Paddy Soil Affected by Saline Irrigation Water

Abstract

To investigate the influence of gypsum application on methane (CH 4 ) emission from paddy rice soil affected by saline irrigation water, two pot experiments with the rice cultivation were conducted. In pot experiment (I), salinity levels 30 mMNaCl (S30) and 90 mMNaCl (S90), that showed maximum and minimum CH 4 production in an incubation experiment, respectively, were selected and studied without and with application of 1 Mg gypsum ha −1 (G1). In pot Experiment (II), CH 4 emission was investigated under different rates of gypsum application: 1 (G1), 2.5 (G2.5), and 5 (G5) Mg gypsum ha −1 under a non-saline and saline condition of 25 mMNaCl (S25). In Experiment (I), the smallest CH 4 emission was observed in S90. Methane emission in S30 was not significantly different with the non-saline control. The addition of gypsum showed significant lower CH 4 emission in saline and non-saline treatments compared with non-saline control. In Experiment (II), the CH 4 emissions in the saline treatments were not significantly different to the non-saline treatments except S25-G5. However, our work has shown that gypsum can lower CH 4 emissions under saline and non-saline conditions. Thus, gypsum can be used as a CH 4 mitigation option in non-saline as well as in saline conditions.

Mitigation Rice Yield Scaled Methane Emission and Soil Salinity Stress with Feasible Soil Amendments

“…Journal of Agricultural Chemistry and Environment found in non-saline control (T1) treatment, which significantly increased with salinity levels 25 mM to 75 Mm and highest GHGI (1.19 g CH 4 /g yield) was recorded in T4 treatment (100% NPKSZn + 75 mM NaCl). Among the amendments, phosphogypsum and biochar significantly decreased yield scaled CH 4 emission (GHGI) in salinity levels 25 mM to 75 mM.It has been reported that gypsum amendments effectively reduced methane emission from rice paddy under saline and non-saline conditions[27] [28]. Under saline conditions (25 mM NaCl), CH 4 emissions were decreased by 23%, 27% and 61% with gypsum applications 1 Mg/ha, 2.5 Mg/ha and 5.0 Mg/ha respectively.…”

Methane Emission Reductions from the Alternate Wetting and Drying of Rice Fields Detected Using the Eddy Covariance Method

“…Similarly, higher salinity levels may represent a potentially inhibiting factor for CH 4 production. − The north field emitted much larger amounts of CH 4 despite having both higher clay content and higher soil salinity, which lends additional support to the effectiveness of the AWD irrigation practice in reducing CH 4 emissions. The north field soils do have higher organic matter content (indicated as LOI and percent carbon content), which is known to increase CH 4 flux potential by serving as a methanogenic substrate. , The north field has above average organic matter content relative to other studies in rice or soil properties in Arkansas (3.5–4.5% in the top horizon), likely correlated to the higher clay content; , compared to the south field (2.5–2.9%).…”

Integrated Rice-Based Shrimp and Crabs Farming: Adaptation to Climate Change and Potential Mitigation of Global Warming in the Coastal Wetlands of Bangladesh

“…It has already been reported that wetland rice paddy acts as a major source of ) which acted as oxidizing agent and electron acceptor, thereby reduced CH 4 emissions [22]. It was also reported that CH 4 emissions were decreased by 23%, 27% and 61% with gypsum applications 1 Mg/ha, 2.5 Mg/ha and 5.0 Mg/ha, respectively at 25 mM NaCl salinity level [23].…”