The Effect of Rice Cultivars on Methane Emission From Irrigated Rice Field

Abstract

Rice plants have been reported to affect methane (CH4) emission from rice fields. The objectives of this study were to determine the effect of rice cultivars on CH4 emission from flooded rice and to develop crop management strategies with low emitting rice cultivars while sustaining high yield. The four rice cultivars studied were Memberamo, Cisadane, IR64, and Way Apoburu. The CH4 emissions were determined in the wet season of 2001/2002 (November-February) using an automated closed chamber technique in an irrigated field condition. Farmyard manure at the rate of 5 t ha-1 was given to the plots to ensure carbon was not limited. Root weight, root length, biomass, and number of tillers were determined at 17, 36, and 57 days after transplanting (DAT). The results showed that the mean CH4 emission was highest in the plot planted with Cisadane (94.8 kg CH4 ha-1), and the lowest with IR64 (37.7 kg CH4 ha-1). The plots treated with emberamo and Way Apoburu resulted an intermediate CH4 emission at the average of 61.1 and 58.9 kg CH4 ha-1, respectively. There was no significant difference in yield between the cultivars tested. The yield of Memberamo, Cisadane, IR64, and Way Apoburu were 5.882, 5.764, 5.873 and 6.065 t ha-1, respectively. Statistical analysis showed that there were no significant differences in the root weight and root length among cultivars. However, Cisadane gave the highest dry matter weight (222 g hill-1) at 57 DAT compared to the other cultivars (175-190 g hill-1). Plant tillers did not show significant differences between the cultivars. Regression analysis showed that CH4 flux was significantly related with root weight, root length, aboveground biomass, and number of plant tillers. This finding shows that the use of selected cultivars, such as IR64, can potentially lower CH4 emission without scarifying yield.

Mitigation Potential and Yield-Scaled Global Warming Potential of Early-Season Drainage from a Rice Paddy in Tamil Nadu, India

“…Many studies have reported that there are substantial differences in the rates of CH 4 emission from different rice cultivars [40][41][42]. The effect of rice cultivars on methane emissions is mostly related to rice growth performance, i.e., the number of plant tillers, and the plant above-and belowground biomass affect CH 4 transport potential and root exudation [40][41][42]. There were no significant differences in cumulative CH 4 emissions between the tested rice varieties in both rice seasons (Figure 5a,b).…”

Sri Paddy Growth and GHG Emissions at Various Groundwater Levels

“…Many findings on CH 4 and N 2 O emission from conventional paddy fields have been reported since the early 1990s. Among others are: under intermittent irrigation, CH 4 and N 2 O emissions have been seen to vary depending on the paddy varieties planted (Husin et al, 1995;Setyanto et al, 2004) and on the fertilizer applications (Cai et al, 1997;Nishimura et al, 2004). CH 4 emission in drained paddy fields is temperature-dependent, and accordingly varies diurnally with its maximum value occurring in the afternoon (Miyata et al, 2000;Purkait et al, 2007).…”

Influence of rice varieties, organic manure and water management on greenhouse gas emissions from paddy rice soils

“…Methane produced in flooded rice soils is emitted to the atmosphere by molecular diffusion, ebullition or plant-mediated transport. Approximately 80–90% of the total CH 4 flux is emitted to the atmosphere from the rhizosphere via the rice plant [ 17 ]. An increase in plant biomass [ 18 ] and tiller number [ 19 ] enhanced CH 4 oxidization activity by enlarging the volume of aerenchyma and enhancing O 2 transport from the atmosphere to the rhizosphere.…”