Effect of the long-term application of organic matter on soil carbon accumulation and GHG emissions from a rice paddy field in a cool-temperate region, Japan-II. Effect of different compost applications-

Abstract

The influence of long-term application of different types of compost on rice grain yield, CH 4 and N 2 O emissions, and soil carbon storage (0 − 30 cm) in rice paddy fields was clarified. Two sets of paddy fields applied with rice straw compost or livestock manure compost mainly derived from cattle were used in this study. Each set comprised long-term application (LT) and corresponding control (CT) plots. The application rates for rice straw compost (42 years) and livestock manure compost (41 years in total with different application rates) were 20 Mg fresh weight ha-1. Soil carbon storage increased by 33% and 37% with longterm application of rice straw compost and livestock manure compost, respectively. The soil carbon sequestration rate by the organic matter application was 23% higher with the livestock manure compost than with the rice straw compost. The rice grain yield in the LT plot was significantly higher than that in the corresponding CT plot with both types of compost. Although the difference was not significant in the rice straw compost, cumulative CH 4 emissions increased with long-term application of both composts. Increase rate of CH 4 emission with long-term application was higher in the livestock manure compost (99%) than that in the rice straw compost (26%). In both composts, the long-term application did not increase N 2 O emission significantly. As with the rice straw compost, the increase in CH 4 emission with the long-term application of livestock manure compost exceeded the soil carbon sequestration rate, and the change in the net greenhouse gas (GHG) balance calculated by the difference between them was positive, indicating a net increase in the GHG emissions. The increase in CH 4 and net GHG emissions owing to the long-term application of the livestock manure compost could be higher than that of the rice straw compost owing to the amount of applied carbon, the quality of compost and the soil carbon accumulation. The possibility that carbon sequestration in the subsoil differs depending on the type of composts suggests the importance of including subsoil in the evaluation of soil carbon sequestration by long-term application of organic matter.

Nitrogen Budget in a Paddy-Upland Rotation Field with Soybean Cultivation

“…In the future, it will be necessary to evaluate the effect of organic matter application on the N budget in the entire paddy-upland rotation system, including paddy rice cultivation. Furthermore, accumulation of soil N due to continuous application of organic matter [6,[48][49][50] is considered to affect the field N budget. Therefore, it is necessary to evaluate the effects of organic matter application on the N dynamics and budget in the field and on crops on a long-term basis.…”

Effects of the Autumn Incorporation of Rice Straw and Application of Lime Nitrogen on Methane and Nitrous Oxide Emissions and Rice Growth of a High-Yielding Paddy Field in a Cool-Temperate Region in Japan

“…2.1.5. GHG Fluxes CH 4 and N 2 O fluxes during the rice growing season were measured per week by the closed chamber method [19][20][21][22][23]. Measurements were made in triplicate for each treatment with one point per plot.…”

Soil carbon and nitrogen dynamics by land use and management changes in East and Southeast Asian countries (soil C and N by LUMC)

“…This review referenced many papers published in a former special section as 'Frontline research in mitigating greenhouse gas emissions from paddy fields' in SSPN (Yagi 2018). This special issue contains four original articles concerning GHG emissions from rice paddies (Kimani et al 2020;Sriphirom et al 2020;Takakai et al 2020aTakakai et al , 2020b.…”

“…Eight of the original articles are from Japan. Takakai et al (2020aTakakai et al ( , 2020b describe the effects of the long-term application of organic matter on soil C accumulation and GHG emissions from a rice paddy field in a cool-temperate region, Japan. They compare the differences between rice straw and rice straw compost applications in Niigata Prefecture (Takakai et al 2020a) and between rice straw compost or livestock manure compost applications over more than 40 years in Akita Prefecture (Takakai et al 2020b).…”

“…Takakai et al (2020aTakakai et al ( , 2020b describe the effects of the long-term application of organic matter on soil C accumulation and GHG emissions from a rice paddy field in a cool-temperate region, Japan. They compare the differences between rice straw and rice straw compost applications in Niigata Prefecture (Takakai et al 2020a) and between rice straw compost or livestock manure compost applications over more than 40 years in Akita Prefecture (Takakai et al 2020b). Nguyen et al (2020 a, b) describe the effects of long-term applications of conventional rice straw and cow dung compost on the fertility of soil used for rice production Nguyen et al (2020a) and the N balance (Nguyen et al 2020b) in paddy fields in Yamagata Prefecture.…”