**3.5 Controlled irrigation**

According to reports, compared with irrigated rice, controlled irrigation can minimize the net emissions of greenhouse gases [26, 27]. During the rice growing season, the soil in the controlled irrigated rice field is kept dry (60–80%), but there is no flooding after the rice seedlings are regreened [28], similar to the water in the rice intensive system (Sato) [26] reported that, compared with traditional flooded rice, CH4 emissions from controlled irrigation rice fields were reduced by 79%, and N2O emissions increased by 10%. The GWP of controlled irrigation was much smaller than that of traditional flooded rice (67%). Peng et al. [27] also reported that the global warming potential (CH4 and N2O) of the irrigation system was reduced by 27% compared to conventional floods. In addition, some authors report that deep-water irrigation (water depth of 10 cm) and permanent humidification, humidification irrigation and water-saving irrigation can also reduce greenhouse gas emissions from rice fields, especially CH4 [29, 30] can be used as a tool to reduce greenhouse gas emissions.

#### **3.6 Straw/residues management**

Crop production inevitably leads to the production of large amounts of straw/residue that are usually left in the field [31]. With the gradual decrease in the amount of organic fertilizers, the rice soil relies heavily on the recycling of straw to overcome the carbon loss caused by soil cultivation and crop harvesting. Although burning straw can ensure rapid seedbed preparation for farmers and avoid the risk of nitrogen immobilization during the decomposition of residues, carbon and nitrogen are relatively large, but incomplete carbon combustion will produce a large amount of greenhouse gases and affect air quality. Produce adverse effects [31, 32]. In addition, N oxides and other fire-source organic compounds can cause the formation of tropospheric ozone. Rice straw is composed of a variety of organic components, such as cellulose, hemicellulose, lipids, protein, lignin, etc., each component's contribution to the improvement of CH4 emission rate is variable. CH4 The discharge rate is very sensitive to the management method of straw entering the soil. Ali et al. [33] reported that the CH4 emission rate of fresh rice straw is higher compared to the non-crop season in rice fields. In a field survey conducted in Zhejiang Province, China, [34] found that the recorded greenhouse gas emissions of early straw incorporation at the beginning of the fallow period in winter were 11% less than the traditional straw incorporation method in spring. Similarly, [35] showed that in the fallow period (60 days before rice planting), the incorporation of residues is beneficial in terms of greenhouse gas emissions and grain yield, compared to the usual application before transplantation. Abandoning rice straw can also be an effective measure, because compared with the combined use of straw, straw removal reduces the emissions of these three gases [36].

*Rice: Worldwide Production, Utilization, Problems Occurring Due to Climate Changes… DOI: http://dx.doi.org/10.5772/intechopen.96750*
