Global climate change, associated with more extreme climate events, has been identified to increase the risks of floods, drought, and fire [1]. Agriculture is easily influenced by climate shifts, and predicted happened with relevant factors including redistribution of water availability and compromised quality, increased soil erosion, and decreased crop productivity [2, 3]. These factors present immediate and localized economic risks to farmers. In contrast, emissions of greenhouse gases (GHGs) pose potential threats to the larger landscape over a long time. Moreover, agriculture is the major source of the GHGs that are driving those changes, contributing about 60% and 58% of the total anthropogenic emissions of methane (CH4) and nitrous oxide (N2O), respectively. With regard to CH4, rice (Oryza sativa L.) production remains the largest emission source from a single sector and accounts for 18% of total agricultural CH4 emissions [4]. Thus, climate change threats rice production systems, which represent negative effects to quality of life at local and global scales. Therefore, development strategies of adaptation and mitigation for rice production systems is an urgent issue currently [2, 3, 5].
China is the largest rice producer in the world, accounting for 16% and 28% of the global rice area and global rice production [6]. Hunan Province (HP) is the largest rice producing region in China, accounting for 14% of China’s rice production [7]. Thus the rice production in HP is very important in China’s food security. However, rice production is very sensitive to climate change with the increasing of rice acreage during recent decades in HP [7]. The uneven spatial and temporal distribution of precipitation in HP, especially during July and October when rice is in large water demand, high evaporation and low precipitation always lead to drought, in addition with poor irrigation infrastructure, which generally influenced the rice production. On the other hand, soils continue to deteriorate as a result of increased chemical fertilizer input, decreased organic fertilizer input, little application of green manure and soil erosion. According to a document released by Chinese government, the formulation and implementation of policies in adaptation to climate change have received high priority [8, 9]. In addition, the local governments in HP had released a notification “The Thirteen Five-year Plan for Low Carbon Development of Hunan province”, in order to build up low-carbon agriculture production systems. However, current knowledge about how to do farm management to implement these governmental plans is insufficient since previous studies were mostly either based on qualitative analysis or concentrated on other regions [7].
Generally, the optimized management strategies in agricultural systems have been identified to be useful to mitigate the GHG emissions, many of current applied technologies that can be implemented immediately [4, 10, 11]. However, most analysts were mainly concentrated on single technologies (e.g. nitrogen management, conservation tillage, or water-saving irrigation) adopted by farmers, which ignored the complementarities and/or substitutabilities of different technologies [12]. The extent of adoption of LCTs is measured by the number of component technologies adopted by rice farmers, which is more complex than the decision to adopt a single technology. The single decision is usually based on short-term profitability considerations, while interrelated adoption implies a more substantial and longer-lasting change in farming conservation [13, 14]. Moreover, technologies had been developed and disseminated as a package with several components by many scientists [15, 16]. Although previous studies have investigated the adoption of technology packages [17, 18], however, these studies are under the background of western countries where integrated management practices are usually adopted in dairy farming. Hence, the uniqueness evaluation of the package of technology is a major contribution of this study that had little studies on the adoption of LCTs investigation in rice farming in China. Therefore, the objectives of this study were 1) to investigate the application level of LCTs by farmers to cope with climate change in rice production in HP of China; 2) to examine factors that affect the likelihood of farmers’ adoption intensity of selected LCTs by farmers in rice production; 3) to examine the effects of policy supports and household characteristics on farmers’ decisions in applying different LCTs in order to mitigate the effects of climate change, and considering the possibilities of adoption of different LCTs simultaneously.
Study areas
Hunan province (HP) is located in Southeast China (24°39′–30°08′N, 108°47′–114°15′E), which has a subtropical humid monsoon climate with an average annual air temperature of 16.4–18.5which mean precipitation of 1200–1700 mm (Liu et al., 2015), 80% of which falls during the rice growing season from April to November. There are nearly 272–300 frost-free days and about 9 months with mean temperature above 10g season from April to November. The province is one of major double rice cropping system provinces in China with 1.5 × 106 ha double rice planting area in 2014. It was divided into three areas as follows: the northern commodity economy type, the central and eastern suburban type, and the southern export-oriented type. Eight representative counties were selected in this study, including Changde, Yiyang, Yueyang, Changsha, Zhuzhou, Shaoyang, Hengyang and Chenzhou (Fig. 1). The selection of the representative counties was based on the climate conditions, natural resources, soil fertility statue, socioeconomic conditions, geographic location and rice yield level amongst counties. The soil productivity statue was judged by the famers according to soil fertility, soil moisture content and topography in each field. Hengyang and Chenzhou in the south of HP represent the low fertility soil areas with low water resources, where the economic conditions are less developed. Changsha, Zhuzhou and Shaoyang in the central and eastern of HP represent the high fertility soil areas with high water resources, where the economic conditions are much better than other cities.
Data sources
Selection of low carbon technologies for the case study
A review of agronomic experimental evidence in previous publications and studies shed some insight into discovering how LCTs help to reduce GHG emission. Retrieved from a keyword search of “mitigation/agriculture” in major scientific database platforms such as Web of Science, SciFinder Scholar and Google Scholar, previous studies that report successful agricultural practices in different regions that obtain higher mitigation potential in terms of soil carbon sequestration rate were collected. Table 1 shows the selection of these practices and the main sources of literature. Eighteen experts from research institutes and universities of regional and national levels were invited to evaluate and prioritize the practices identified in the above procedure with reference to socio-economic and environmental criteria. In choosing experts, the following guidelines were followed: 1) a minimum of 5 years’ working experience on issues related to GHG mitigation in agriculture; 2) sufficient knowledge of the different cropping management and systems so that the expert is able to cope successfully with the selected mitigation practices contained in the survey; 3) regular contact with farmers and extensive knowledge of the productive sector is prioritized. Apart from the survey of experts, the farmers were also asked to complete questionnaires containing selected practices from the literature review. The aim of the survey of farmers is to assess the current barriers to the adoption of the above practices in the case study area of HP. Though the survey of farmers also includes what other relevant mitigation measures adopted by them are, it gains no significant responses. The study of mitigation practices has revealed various options that could be applied in the present study.
Questionnaire survey of low carbon technologies for the case study
The LCTs survey was a multiphase survey of rice farms in eight counties of HP in the present study. In terms of sampling, stratified random sampling was adopted with four parts of questionnaire including 1) overall information about the household and the household head; 2) farmer’s attitude towards climate change, low carbon agriculture and risk; 3) characteristics of the farmer’s filed; 4) external environment characteristics. The selection of variables has considered both economic theory and previous similar studies that conducting the adoption measures against climate change [19, 20]. There were 40 representatives were conducted as pre-tested at Swan village, Ningxiang county of HP in order to test the reasonability of the questionnaire. Finally, the questionnaire was efficiently improved based on the comments and suggestions. The reliability analysis was calculated by the Cronbach’s Alpha method, the results showed the Cronbach’s alpha coefficient were all over 0.7, which indicates that the data has good internal consistency of questionnaire and survey results have a high credibility. Finally, two townships in each county and two villages in each township for field surveys were randomly selected. Moreover, in each village, 20 farm households were randomly selected and interviewed. The interviews were carried out among rice farmers during the period June-October 2013 and 2014. A 640 investigate dataset was collected from farmers across all eight counties. Ultimately, 555 surveys were finally used in the present study, which provided all information.
Data and variable definition
Explanatory variables used in the econometric model and their expected signs are given in Table 2. Prior expectations about the relationships between the explanatory variables and the technology adoptions are based on theoretical underpinnings and from previous empirical results. On average, the age of rice farmers was around 50 years old, and rice farmers have approximately 6 years of formal schooling, 19 years of rice farming experience and 4 household members in HP. Farmers in this region have less on-rice income, accounted for approximately 25 ~ 49% of total revenue. The most of rice farmers in HP are more risk-averse, and lack of awareness of low-carbon agriculture. Each rice farmer has an average of 4 ha farm acreage, and very few rice farmers achieve farm mechanization, although they have a better supply of irrigation water in Hunan province. About 61% the rice farmers think their paddy soil is barren and unproductive. In addition, the famers in Hunan province find it difficult to obtain bank credit and technical support from government. It is notable that only 5% of the sample participated in on-farm demonstrations, and 10% of sample received training and technical assistance from government organization. About 61% rice farmers had achieved technology subsidies in this region.
Table 2
Low carbon technologies | Description of the LCTs | Potential emission reduction rate | Sources |
New rice varieties | Rice varieties, such as pest-resistant genetically modified varieties, efficient use of nitrogen fertilizer varieties, which can reduce the use of pesticides and nitrogen inputs or increase rice yield, or improve their oxidation in rhizosphere and transmission capacity, finally markedly reduce CH4 emissions. | 0.51–1.39 t CO2-eq ha− 1 | Tao, 2008; Fu et al., 2010; Xu et al.2015 |
Conservation tillage | Reducing or avoiding tillage practices, which can increase soil carbon storage through reducing microbial decomposition, and promoting crop residue incorporation into soil. | 0.23–0.71 t CO2-eq ha− 1 | Zhang et al., 2013; Chen et al., 2014; Xue et al., 2014 |
Optimizing fertilizer management | Changes of fertilizer application rates, for instance, applying fertilizer depending on crop needs in different rice growth phases in order to increase fertilizer use efficiency thus reducing GHG emissions, especially nitrous oxide. | 0.36–0.62 t CO2-eq ha− 1 | Snyder et al., 2010; Shang et al., 2012; Chen et al., 2016 |
Water–saving irrigation strategy | This practice usually comprises one or several drainage periods in paddy soil, which prevents the development of soil reductive conditions and markedly reduces CH4 emissions. | 0.38–1.29 t CO2-eq ha− 1 | Ahn et al., 2014; Win et al., 2015; Xu et al., 2015 |
Pesticide reduction technology | It consists of reduced herbicide, hand weeding or pest control with light trap in order to reduce the pesticide inputs, thus reducing GHG emissions. | 0.48–1.85 t CO2-eq ha− 1 | Lei, 2013; Chen et al., 2016; Zhang et al., 2016 |
Planting green manure in fallow winter season | Planting green manure in the winter fallow field, increases soil carbon stores and reduced fertilizer use, thereby reducing nitrous oxide emissions. | 0.12–1.87 t CO2-eq ha− 1 | Xu et al., 2016; Shang et al., 2016; Wang et al., 2015 |
Planting-breeding technology | Common cultivation aquaculture in paddy fields, aerate the paddy soil by burrowing into the soil for searching food, prevent a drop in the redox potential and lower CH4 emission | 0.78–2.12 t CO2-eq ha− 1 | Datta et al., 2009; Bhattacharyya et al., 2013; Xu et al., 2017 |
Statistical summary of dependent variables for the Poisson and the multivariate probit models. The Independent variables are the same across all models (n = 555) |