Globally, agriculture has been considered as one of the major sources of greenhouse gases (GHG) (Chauhan et al., 2006; IPCC, 2007). In terms of anthropogenic GHG emissions, agriculture accounted 14%, which contributes 47% CH4 and 84% N2O emissions (IPCC, 2007; US-EPA, 2006). Rice is staple food in many countries and also an important part of the diet for a large portion of the world’s human population (Maraseni et al., 2009; Smith et al., 2008). Furthermore, the world’s annual rice production must be increased from 518 million tons in 1990 to 760 million tons in 2020 (International Rice Research Institute, 1989) to feed the growing population. The yield potential of rice largely depends upon the proper management of fertilizer and irrigation water, but farmers are using them extensively for increasing yields which incur cost and also has adverse effect on global climate. The cultivation of paddy rice contributes toward the emissions of the most important greenhouse gases (GHGs) responsible for global warming viz; CO2, CH4 and N2O (Jacobson, 2005; Allen et al., 2009; Bhattacharyya et al., 2009).
Mitigation of GHG emission from farming systems is the current hot issue and extensive research works are going on throughout the world for developing eco-friendly as well as cost-effective technologies to mitigate the emission of methane and other GHG from rice fields (Zschornack et al., 2011; Harada et al., 2007). Different mechanisms for mitigating methane emissions have been proposed by the researchers including fertilizer use, proper water management and altering magnitude of organic amendment dominate to enhance yield potential of rice, as well as reduce CH4 fluxes (Jane et al., 2007; Liou et al., 2003).
Incorporation of rice residue into the soil is safe eco-friendly practice and it gradually improves soil organic carbon, phosphorus and potassium contents (Prasad et al., 1999) but it leads to increase methane emission due to flooding during rice growing season (Summer et al., 2003; Pathak, and Wassmann, 2007). The mechanisms behind CH4 emission thought to be considered as creating anaerobic condition that favor more emission (IPCC, 2006; Hardy, 2003; Wang et al., 2000; Yao et al., 1999).
On the other hand, draining the wetlands during the rice growing season for once or several times, known as intermittent drainage or alternate wetting and drying (AWD) significantly lower CH4 emissions (Smith & Conen, 2004; Yan et al., 2003). Continuous flood irrigation emits higher CH4 than intermittent irrigation (Towprayoon et al., 2005, Nagroho et al., 1994; Minamikawa and N. Sakai, 2006.) which tends to turn down near zero emission during drainage period but increase immediately after re-flooding. A single drainage reduces emissions by ?40% (Yan et al., 2005, 2009) and found from a study in Orissa is that methane emissions of 16, 19, 27 and 36kg ha-1 per season from alternately flooded, continuously flooded, alternately flooded with 2t straw and continuously flooded with 2t straw, fields respectively (Adhya et al., 2000). Although straw addition increased the methane emissions but when combined with alternate irrigations systems, ultimate emissions was less than continuous flooding. Studies reported that AWD serve as mitigation potential of GHG by 35% accompanied and reduced rice yield 7%. So, short period drainage during rice flowering stage considered as compromise of decreasing GHG emissions and also compensate the yield penalty (Towprayoon et al., 2005; Ma et al., 2011; Maraseni et al., 2007). Improved water management can decrease methane emissions by avoiding waterlogging and keeping the soil as dry as possible (Xu et al., 2003; Cai et al., 2003; Kang et al., 2002) and adjusting organic material addition time (e.g. incorporating organic residue in the dry period instead of flooded periods; Cai & Xu, 2004; Xu et al., 2000;), composting the residues before incorporation (Wang & Shangguan, 1996; Wassmann et al., 2000). Therefore, the relationship between organic amendment and intermittent drainage systems should be investigated in order to find the best compromise for CH4 emission without affecting the yield potential.
Worldwide 80% of rice is grown in developing countries mostly by the smallholder farmers in low income groups (Hardy, 2003). Therefore, motivation of small holder’s famers from traditional rice cultivation towards organic farming will reduce the GHG emission. As the traditional practices applied higher fertilizer, pesticide, water and others input which tends to release more GHG to the atmosphere. While the organic farming solely relies on organic amendment, discards chemical fertilizer and same the time builds up the soil organic matter status. The farming practices would be low GHG farming and also climate neutral (Niggli et al., 2009).
Mitigation options for GHG emissions as stated by Smith et al. (2007) and Bellarby et al. (2008) and claim that both farmers and policymakers will face challenges from the GHG-related changes needed in agriculture. The main factors restrict farmers for adapting climate smart rice farming includes little information broadcast about climate change and less activity by agricultural extension service; high cost of farm inputs, limited irrigation facilities, labour and income constraints and government negligence towards risk management against climate change, (Ozor et al., 2010). Therefore, identification of innovative model farmer groups and adoption of climate smart rice farming techniques need to be explored.
Climate change adaptation is an expensive practices and the cost mostly revealed via the necessity of intensive labor use. Thereby farmers always faced problem due to unavailability and higher cost of farm labor. But farmer only needs time to learn about new techniques, once when they gain experience and become familiar to adapt the processes, labour requirement will be less. Another aspect, as the most of small holder rice farmers are pro-poor, that’s why insufficient money liquidity hinders farmers to have access for necessary technologies and resources need for facilitating climate change adaptation strategy (Mishra and Salokhe, 2011. Hence, farmer cannot adapt the low GHG mitigation practices if they don’t have sufficient family labor or sufficient fund to hire the labor (Ozor et al., 2010). Thereby, financial support from governance level is crucial to overcome barriers of the local farmers in the form of subsidy.
Electronic information technology is used to collect, process and analyze multisource data for decision-making (Sonka, Bauer and Cherry, 1997). Different extension methodologies can be used for the dissemination of information on climate sound rice farming by diffusion of innovation (Oladele, 2013). Smart phone apps and web-based decision-support tools has developed for providing stakeholders with ready access to data-intensive research results necessary for on-farm management by farmers and strategic decision-making by policymakers (Kruger et al., 2011). As for example- mobile or online access of IRRI knowledge bank, Radio drama in Nigeria (World Bank, 2012), community radio such as Climate Radio in Ghana, Krishi Radio and television programs in Bangladesh (ELDIS, 2013), cyber village project in Mannila, Philippines etc are recently applied technologies to reach the climate sound and site specific nutrient management at farm level (Oladele, 2013).
Developing climate smart farming practices necessitate decision support from society to adopt at farm level. This approach depends upon decision criteria based on water management (wet and dry system) and addition of organic amendments. Organic manure incorporation is easier but for water management, farmers have to control the level and number of irrigation in the rice field, which may make it difficulties to follows. Low GHG emissions practices also involved hidden cost that is difficult to articulate in monetary term. At the beginning, farmer has to overcome the unexpected losses through trials and error as the processes are more detailed and complicated. At the same time, knowledge and skill needed by farmers to invest capital and time with regards to achieve success. The irrigation system in a particular area is based on a community or a group decision, which means that an individual farmer, who applies a different irrigating pattern will affect working schedule of the community or the group (Arayaphong, 2012). Existing electronic decision support system should be improved including above mentioned climate smart technique to adopt successfully at farm level. Smallholder’s innovative model farmers groups should need to motivate and address them about climate smart rice farming with less input and higher income by building linkage among extension officers, research institutes and recently developed electronic information devices for successful implementation at grass root level. Although low GHG rice farming practices are indispensable to cope up global warming and also need proper implementation at the farmer level, but little research work has done focusing decision support system and integration of climate sound information into the electronic data base. Therefore, the proposed study will be carried out to fulfill the following objectives:
This section will be addressed the above mentioned questions step by steps.
Experiment I: GHG mitigation potential of water management, when utilizing complex organic manures in rice farming
As we already know that rice field contributes a significant amount of GHG especially CH4. The emissions strongly correlated with the depth of water table and also type of organic manure used as well as their timing of applications.
In this experiment I will apply various types of organic manures such as compost, rice straw and green manure at different rates (6 ton/ha and 12 ton/ha). Rice straw and green manure will be chopped properly into small pieces before applying into the fields. After that the application of organic manures in the fields will be done at different times such as before rice transplanting, at tillering stage and at flowering stage. Lastly the comparison will be drawn between the continuously flooded and intermittently flooded fields in terms of GHGs flux from these experimental plots.
Measurements of methane emission
Methane flux from the rice field plots will be monitored whole crop cycle. Emitted CH4 will be sampled by using the manual closed chamber technique (Datta et al., 2009; Rolston, 1986). To make the system airtight Plexiglas chambers (50 cm _ 40 cm _ 100 cm) will fix on the aluminum channels, inserted 10 cm inside the soil with the channels filled with water. The air inside the chamber will be mixed by a battery operated fan to get a homogenous composition (Ghosh et al., 2003). Methane concentration will be measured by flame ionization detection (FID) gas chromatography (Ramakrishnan et al., 1995).
From the experiment we will be able to know which water management and organic matter application approach will provide lowest GHG emission from the rice farming and suitable time for incorporation of organic complex will be found from this experimental set up.
Experiment II: Investigation of GHG mitigations approaches in a series of farm types and evaluation of their mitigation potential
The main ambition of this experiment is to generate data from different farming system and what are the driving forces for GHG mitigation potential that could be included in a decision support system. I will use the lowest GHG emission technique that will come up from the first experiment. The practices will be applied in a series of farm types to quantify and compare costs, benefits, expected profits and risks between the conventional and organic farming with intermittent drainage by using CBA basis and Monte Carlo simulation. According to Broadman, et al. (2006), a few steps are taken in a CBA; specifying alternatives or scenarios of the project, identifying key players (who will be affected by the project), collecting, and measuring costs and benefits. To begin with standings identification, a farmer is the main actor who is affected directly from rice production through a profit and production cost. The second actor is the environment because nature and ecological system are impacted by toxicity and exploitation of resources from rice production. Lastly, a society is regarded as third actor because an impact on a farmer and the environment also affects the society.
Comparative analysis among different farm types will be done in respect to cost and benefits in terms of water, labor and nutrient efficiency and impact on yield and productivity. Finally, the society will make decision to accept farming typology based on higher farmers profit and lower environment damage. A structured set of questionnaire will be sent to the local farmers mentioning the constraints facing during cultivating low GHG emission rice practices in their own farm.
Experiment III: Improvement of electronic decision support systems including elements of water use efficiency, organic fertilizers and greenhouse gas emissions
This experiment will focus on the exploring the driving factors of different system and potential of implementing GHG mitigation practices. This should also include aspects of farmer awareness and priorities as well as knowledge systems, leading towards the decision support tool aspects. The data base will generate from experiment II about nutrient use efficiency of organic manure, low green house gas mitigation potential, irrigation scheduling for intermittent drainage from different farm types will be incorporated in the existing electronic information systems. After that a series of test will be conducted for farmer awareness rising on environmental impacts of farming.
There are few electronic information system has been developed by IRRI for transferring updated news to the small holder farmers. In Philippines, NMRiceMobile (Nutrient Manager for RiceMobile) has provided the rice growing farmers and also the extension workers with free guidelines for fertilizer application by using mobile phones which has been widely used by local farmers since 2011. Through text messages (SMS), they can receive information on the amount, right time and the kind of fertilizer should be applied to maximize production and income from their rice cultivation. Method demonstration, result demonstration and field day will be conducted at the farm to inspire the farmers in a community.
Collected will be analyzed to compare the mean difference by using DMRT as outlined by Gomez and Gomez, (1984). Analysis of variance will be performed using the Proc Mixed procedure of Statistical Analysis System (SAS Inst., 1999).
6. RISK AND ETHICS OF PROPOSED RESEARCH
The main aspect of this study is to propagate the climate smart rice farming to the farmers. Glass house experiments will be carried out to know the best combination of organic matter use and water application along with timing of organic complex incorporation. Methane and nitrous oxide flux need to be measured carefully. After that transfer of this knowledge to the farm community and their acceptance will may be one of the constraint. As the farmers in a particular locality cultivate rice by following their own traditional system, so motivate them to the new techniques arise the questions of acceptance. Generally local communities decide the irrigation system in a particular place. Therefore, new irrigation practices like alternate wetting or drying or intermittent drainage might interrupt the normal irrigation scheduling. This may create new conflicts among local farmers.
Intermittent irrigation is difficult to manage especially for a farmer, who is lack of water resource accessibility. These production processes requires more time and labour use than conventional system. Time and labour constrains can be overcome by proficient management. Water control is also a serious constraint because the process is complicated and detailed, which is not suitable for a farmer who has difficulty in water resource accessibility. Besides, a farmer needs to be trained and educated about new innovative method, which is also a constraint and cost for a farmer as well.
Further interesting point is risk-preference of a local farmer. As mentioned in the introduction, an agricultural yield gain depends on an uncontrollable factor, which means that a farmer has to take responsibility of riskiness by him- or herself. Therefore, risk analysis is also an important factor in decision making. Although climate smart rice technique will generates economic and sustainable benefits to a farmer’s household, but an investment in the technology is higher than the normal system. Variations in labour cost and interest rate are the main constraint obstructing a farmer to change water harvesting pattern. Therefore, government or policy maker should facilitate the credit system for farmer’s motivation.
Inclusion of climate sound rice farming tactic into the electronic decision support might be another barriers. Sometime there is knowledge gap between research station and farmers level, so if the farmer not aware about this practice, successful implementation would be impossible.
The main outcome of this study is to develop climate smart rice farming strategy. Rice cultivation responsible for significant GHGs emissions to the atmosphere and contributes greatly for global warming. On the other hand, fertilizer causes higher production costs which in turn emit CH4 and N2O after applying to the fields. While the use of organic manure build the soil nutrient pool and also reduce the dependency on fertilizer purchase but also contribute to a extent CH4 and N2O emission. Their emission strongly correlated with water management. Therefore, sound water management technique will be found from this experimental study. Various studies has already been conducted on rice straw incorporation in continuous flooding system and methane emission flux but intermittent drainage practices during the rice growth stages largely ignored in these study. Mechanism for methane emission from the flooded condition due to decomposition of organic matter enhances methanogenesis process by creating anaerobic conditions. Therefore, intermittent drainage can stop these processes as aerobic condition will develop by draining the excess water from the field for while.
The main actor in this study is the small holder farmers. Newly developed method will need societal acceptance to adopt at farm level. Therefore, cost benefit analysis will be done to encourage them which techniques will provide higher return by utilizing limited resources of fertilizers and water use.
Finally this newly innovative technique should be integrated in the existing electronic decision support system including the information of nutrient use efficiency of organic manure and low green house gas emission practices. This information base will help to disseminate the climate sound rice farming practices to the end users. Rice farmers must upgrade and well equip themselves with the scientific principles of rice paddy ecosystems management by applying sound rice cultivation techniques.