The study area or the PLR consists of nine counties which belong to three cities (Nanchang, Jinjiang and Shangrao) in Jiangxi Province. This area was chosen for the following three rules:

(1) The grain production conditions of the PLR are very well, and the grain supply is very important to the social and economic stability of Jiangxi Province. Also, the PLR is the important part of Jiangxi Province most affected by urbanization (e.g., Nanchang metropolis). Therefore, farmers’ behaviors in terms of RCS selection change frequently.

(2) Agricultural production in the PLR is relatively well developed, and it is the main supply base for commercial grain in Jiangxi province. As a typical single/double cropping rice planting area in the middle and lower reaches of the Yangtze River Plain, the rice MCI level in the PLR is not only affected by social and economic factors such as urban development, but also restricted by natural factors such as water-level changes of Poyang Lake. Therefore, this region is representative in revealing the complex interplay of social economy and natural environment which influences the decision-making of local farmers.

(3) There are a great deal of basic data and relevant information available in the PLR. The land use and household survey data for this study derived from the Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University.

The data used in this study came mainly from farmer interviews in 2014/2015. Many studies have proved the use of household survey methods to study the dynamics of social and economic phenomena as well as regional development trends (Yin et al., 2003; Feng et al., 2010; Liu et al., 2012). Large numbers of surveys are needed to reveal regional differences, so the initial sample number was larger than 400 and it was also adjusted according to the actual situation.

Random surveys of local farmers in the PLR were conducted during two periods of August 12-20, 2014 and March 15-21, 2015. Depending on accessibility and feasibility, the selection of village household samples was generally based on its general distribution and then adopted a stratified and random sampling way to ensure the reliability of collected data. First of all, therefore, based on the current situation of the lake area, we aimed to sample from the whole area, considering different levels of grain production and variations in topography for rice planting. Nanchang County, located in the southern part of the PLR, and Duchang and Poyang counties in the hilly region were selected. Secondly, stratified sampling of farmers was carried out in terms of age, gender, rice planting area, household size, etc., while individual villages were selected to represent the county with large amounts of arable land. Finally, random samplings of households were used to carry out surveys in the paddy fields and harvesting areas. In order to ensure the validity and reproducibility of the data, direct interviews with farmers was also adopted as part of the survey strategy and a large number of field records and geo-tagged photographs were thus obtained.

Farmers’ behaviors with respect to RCS were mainly surveyed by questionnaire, and farmers’ selection of single/double cropping rice and the related MCI were statistically analyzed. This paper studied the differences in the rice growing behaviors of farmers in the PLR, analyzed the spatial characteristics of rice selection, and then puts forward practical targeted strategies to ensure stable agricultural production in the PLR.

According to the sampling principles outlined above, a total of 112 villages and 405 households in 75 villages or towns in 9 counties of the PLR were selected for the questionnaire survey. Directly after the survey, the groups reviewed, discussed and checked the results. A total of 402 valid questionnaires were obtained, with an effective rate of 99.3%. The distribution and statistics of field samples in the villages and towns are shown in Table 1. A total of 15 households (3.7%) in the PLR were found to have transferred the possession of their land or to abandoned their cultivated land. In general, the survey sampled a wide range of locations (plains and hilly area), and covered all age and gender groups.

First of all, a comparison of farmers’ rice planting patterns in different counties (Fig. 2, Table 2) shows that there are significant variations in the selection of cropping systems. Specifically, over 80% of double cropping rice was in Yugan, Nanchang and Jinxian, where it accounted for 95.35%, 86.96% and 83.64%, respectively. Both single- and double cropping rice were cultivated in Poyang and Xinjian, with the proportions of farmers that planted only two-cropping rice in the two counties were 65.75% and 59.26%, respectively. By contrast, the counties that planted mainly single cropping rice were De’an, Xingzi, Duchang and Yongxiu, and the proportion that planted single cropping rice was extremely high in these counties. In addition, the mixed planting ratios of single and double cropping rice in Poyang and Jinxian were relatively high, accounting for 12.33% and 9.09%, respectively.

A comparison of Fig. 1 and Fig. 2 show that the overall rice planting pattern in the PLR has a significant difference between the north and south. Double cropping rice was dominant in the northwest of the PLR, while the single cropping rice was mainly in the southeast. According to our survey and statistics, the current situation is strongly linked to planting traditions, and is shaped by local climate, terrain, water and land conditions, as well as long-term support from agricultural policies and the distance from urban areas (Li et al., 2014). Specifically, double cropping rice is distributed intensively in the main estuarine delta, while single cropping rice is distributed widely in the suburbs of built-up areas of cities and counties and around the main lake branches (Li et al., 2011). In the north, more cash crops including cotton in the summer and rape seeds in the winter, which is highly related to local climate features (Lin et al., 2010; Huang et al., 2009).

A second comparative analysis of RCS (Table 2) found that rice farmers with only double cropping rice constituted the largest proportion, accounting for 56.85% (a total of 220) of the respondents. Among single rice planting counties, Duchang, Xingzi, and Yongxiu ranked the top three, with 39 households (27.66%), 25 households (17.73%) and 24 households (17.02%), respectively. The planting proportions with only double cropping rice in Nanchang, Poyang, Jinxian and Yugan were large, accounting for more than 20% of all farmers following this strategy. Among the farmers surveyed, the mixed planting of single- and double cropping rice was most common in Poyang, accounting for 34.62%. However, data for De’an was limited by the small sampling size of single cropping rice. While this does not really reflect the true characteristics of their rice planting, it still gives a strong indication of the prevalence of single cropping rice planting in the region. In addition, 29.6% of the surveyed farmers in the PLR changed their RCS during the past five years, with 14.2% of them changing from double cropping to single, and 10.8% from single to double. Furthermore, it was found that 44.4% of the main production areas were actively or passively abandoned.

The degree of land use intensity is the ratio of the total area sown to the cultivated area for the whole year. As far as the paddy fields are concerned, it is represented by multiple cropping index, which reflects the utilization intensity of paddy fields. According to the statistical analysis (Table 3), the MCI in the PLR was mainly low with an average of 1.55. Specifically, the proportion of farmers with their MCI lower than 2.0 was 56.33%; while the proportion with an index of 1.0 was 34.63%, and the proportion higher than 2.0 was 43.67%.

For the nine counties in the PLR, there were significant differences in the MCI.

(1) For the interviewed farmers whose the MCI were 1.0, De’an accounted for the highest proportion of the survey samples. Second, Xingzi and Yongxiu included 25 and 24 households respectively, accounting for 92.59% and 82.76%, respectively. The smallest, one household in Yugan, only accounted for 2.33%.

(2) Among the interviewed farmers with the MCI in the range of 1.0-1.5, Xinjian had the highest proportion of samples (29.63%). The largest sample was in Poyang Country (20 households). Nanchang has only one household, merely accounting for 1.45%.

(3) Among the interviewed farmers with the MCI in the range of 1.5-2.0, the largest sample of surveyed farmers was in Nanchang (10 households). The surveyed farmers of Xingzi and De’an all planted single cropping rice.

(4) For households with the MCI over 2.0, Nanchang had the largest sample size in the region, with 50 households, while Yugan had the highest proportion in the research sample (79.07%).

Through analysis of the questionnaires, it was found that there were significant differences in the MCI by county. In Nanchang, the MCI were relatively high. Most farmers (72.46% of them) chose to plant double cropping rice. In Xinjian, the MCI of different levels were relatively balanced, indicating that local farmers chose different cropping systems. The MCI of Yongxiu was low, and single cropping rice was dominant. The MCI of 82.76% of households was 1.0. The MCI of De’an and Xingzi were very low (less than 1.0), with over 90% of farmers. Duchang’s MCI were relatively low as well. Most farmers planted single cropping rice, and 77.55% of them were at the level of 1.0. The MCI of the interviewed farmers in Poyang was 2.0, where farmers chose either single cropping or double-season rice. The MCI more than 70% of surveyed farmers was 2.0.

When the MCI of rice in the PLR (Table 3) is combined with Fig. 1, it can be seen that the land-use intensity shows obvious north-south differences. Since paddy fields are being reduced via occupation and transformation, it is worthwhile that specific strategies to increase the cropping area and/or double cropping index were proposed accordingly, so as to enhance grain supply in the future.

Generally, the decline of grain yield is caused not only by decrease in farmland, more importantly, the vast decrease in the area planted. At present, China is faced with a reduction of high-quality cultivated land. The main reason for the decrease in the grain planting area is that, aside from the low market price of grain and the facts that farmers make little profit from planting grain, the choice of planting area according to local conditions is especially critical. In central China, the typical area of single- and double cropping systems (PLR for example), has better light, heat and water resources than elsewhere, and more than 80% of the counties is given high attention over grain production. For example, the PLR is a national grain production base. In Jiangxi Province, the overall cultivated land quality is higher, and large-scale management enables reasonable economic returns. However, the water-level seasonality of Poyang Lake causes the interannual or annual fluctuations of rice planting in the polder area, with frequent changes of RCS and, ultimately, an unstable grain yield. Our household survey showed that the land in the lake area (e.g. Liuhu Village in Xinjian County and Guxiandu Town in Poyang County) was subject to the seasonal influence of precipitation due to climate changes, which affected the flooding of paddy fields, especially the transplanting of double cropping rice.

The rapid growth of social economy in the PLR brings benefits to food production, but the associated development also squeezes the space for food production, putting agriculture at risk of being swallowed up by other uses. In view of the unique planting environment seen in the lake area, combined with remote sensing monitoring (Liu et al., 2016), the government should, first of all, strengthen the protection of cultivated land, keeping a clear demarcation of cultivated areas and actively promoting consolidation. Secondly, a comprehensive, planned and systematic improvement of cultivated land resources should be carried out in the lake area to reduce the contradiction between the aim of increasing grain production and the shortage of cultivated land. Thirdly, on the basis of ensuring resilience, the quality of basic farmland should be improved so that it can survive droughts, floods, and others disasters. Specifically, a major role should be given to the five rivers basin (Ganjiang, Fuhe, Xinjiang, Raohe and Xiushui) in the future, which is the key to strengthening regulation in the rest of the region. Taken the Ganfu plain irrigation area formed by Ganjiang and Fuhe as an example, improvements should be made by expanding the cultivated land area, improving the field roads, reconstructing the farmland network, promoting irrigation and other measures. These steps would make full use of the lake area’s rich water, climate and soil resources for strengthening the lakes’ cropping potential, and intensify the use of existing resources, using the embankment land to increase grain output.

As rational people following the path of “economic man”, some farmers (especially those in the suburbs) still tend to plant non-grain crops due to the low efficiency of grain production, and some have abandoned land. Variations in rice planting patterns in the lake area are common. In view of this, the lake area should actively respond to the need for national food security, combining its regional characteristics to adjust the planting structure of grain crops, and play to its strengths. For example, since the dominant type of cultivation is rice planting, it thus should be expanded into especially double rice planting.

In terms of the Poyang Lake Region (PLR):

(1) Combined with differences in agricultural supply-side reform, as well as social and economic development, highly urbanized areas should be encouraged to develop the economic benefits of suburban agricultural development (growing vegetables, etc.), in order to offset the loss of food supply capacity caused by urbanization. In addition, area with relatively low levels of economic activity and urbanization, generally located in the peripheral regions of Poyang Lake, are more suitable for grain and they can be actively encouraged to grow double cropping rice and thus enhance grain production.

(2) The Poyang Lake Plain has many tributaries and deltas (e.g. Xinjiang river delta) that are strongly influenced by changes in the water level of Poyang Lake. Although the rice fields are fertile, the survey found that the lakeside paddy fields are easily waterlogged during the spring- summer season and/or suffered from drought when the lake level drops. Therefore, rice cultivation in the region around Poyang Lake should consider single cropping that would make full use of land resources such as the ponds of Jinxian County (Li et al., 2015). In low hilly land, suitable water and soils offer favorable conditions for rice planting. If land leveling was carried out, a large amount of double cropping rice could be planted. For example, if a large area of land in Tutang Town of Duchang County was leveled, the planting area of double cropping rice would increase substantially.

In the PLR, rice cultivation is mainly carried out by farmers and strongly affected by market forces. In addition, the elderly and women are increasingly becoming the main food producers and labor force. According to our analysis, the average age of the rural labor force in the PLR was 54.2 years old, among which 94.1% of the surveyed households are over 40 years old, followed by 67.8% over 50 years old, and 27.2% over 60 years old. In order to improve the enthusiasm of farmers for growing grain, the state has introduced a series of policies (such as direct subsidies for grain) to strengthen agriculture and benefit the farmers. Grain subsidies can not only enhance farmers’ interest in grain growing to some extent, but can also guide their planting behavior. Other studies (Li et al., 2015) have shown that the grain subsidy in the PLR had little obvious incentive effect on the rice cropping decisions of farmers, but did not deny the protective effects of grain subsidy and minimum price guarantee for farmers. As far as the survey results of farmers in the PLR are concerned, the influence of differences in local planting structure mean that the subsidy standards in various regions are quite different (mainly in terms of subsidy amount, etc.), which leads to a widening income gap in agricultural production and further aggravates the differences in selection of RCS at the regional level. In view of this, preferential support policies such as additional agricultural subsidies could be formulated to attract and promote new generations of young labor force to become skilled, highly knowledgeable and capable farmers. This would inject new vitality into the ageing population of agricultural producers in the lake area. This effort also resonates with the current national push to encourage groups of high-quality young people to return home to build a new countryside.

In the future, starting at the grassroots level, the policies should encourage large-scale grain planting, and fully implement the subsidy system (such as agricultural insurance subsidies and land transfer subsidies) and minimum purchase price protection, so as to improve farmers’ enthusiasm for growing grain. In terms of grain subsidies, the cropping system (area) of grain planting can be piloted to replace the simple land area subsidy, from a single subsidy only considering area and paddy land or household population to include the multiple-copping numbers, so as to increase the planting area of double cropping rice and increase MCI. On the business side, the government should accelerate the work of land confirmation, registration and certification, so as to actively develop various forms of medium-scale management and new types of agricultural businesses. For example, in the tourist towns of Poyang County, Gaojialing Town, and Changshanyan Town in Jinxian County, the large towns and villages carry out more planting or larger-scale operations as a result of land leveling. Consequently, the RCS is mostly double cropping. In the future, we should take advantage of land circulation in the PLR as an opportunity to establish rice cooperatives and popularize large-scale management. This would not only make efficient use of land resources and save input costs, but also improve the rice replanting index, thus enhancing regional food security.

The input of resources and technology can directly affect the output efficiency of cultivated land and the farmer’s planting decisions. The varied grain varieties and uneven growing environment have become the main factors restricting the increase of grain yield per unit area. At present, with the strong reduction in cultivated land resources, the grain size advantage of Jiangxi Province is obvious but the production efficiency remains low (Xiao et al., 2015). Therefore, it would be wise to promote scientific supply-side reforms in a pragmatic way, while actively improving the yield per unit area of crops. In the context of the PLR, small farmers should continue to encourage intensive cultivation and improve the quality of their food products, while for the farmers with large land area, a number of factors should guide development. On one hand, the policy should attract more investment in science and technology and develop relevant environmental governance, thus creating good conditions for rice growing. The phenomenon of abandoned land should be gradually eradicated. Also, other issues including land pollution caused by industrial development, such as the eastern part of Nanchang County, which was forced to abandon its paddy fields because of chemical pollution.

On the other hand, in the future, the research and development on rice cultivation should be strengthened to improve the yield per unit area of grain through high-quality and high-yield varieties. In addition, farmers in the lake area have long adopted the intensive farming methods and agricultural production is entirely the result of the behavior of farmers and families. We should take the opportunity of land circulation to improve the systematic cooperation among company, community, farmers and farmland, in the form of the implementation of road, water, ditch, electricity and other aspects of comprehensive reforms, at the collective and household level. This would further enhance agricultural industrialization, modernization and then increase the multiple cropping index. At the same time, we can expect a steady increase in the supply of grain products in terms of quantity, variety and quality to meet the needs of consumers, truly forming an effective supply with reasonable structure and sustainability. Only then can we stimulate grain production from the perspective of consumption.