Through scientific improvement of land productivity and labor productivity to ensure a long-term and stable increase in food production capacity and strengthen the base to cope with the uncertainties of global climate change. 3) Enhancing social benefit is the emphasis of SICLU. It requires increasing attention to social issues and human welfare brought by the cultivated land use, such as dietary needs, waste reduction, market transactions, distributive justice. In particular, paying more attention to the cultivated land users’ needs in microfinance and agricultural technology. By strengthening policy publicity, supervision and guidance to form a restraint mechanism for saving and intensive land use and an encouragement mechanism for consciously protecting the environment. From the perspective of participants and external social and economic environment, the SICLU goals further strengthen the value responses and linkages of agriculture, countryside and farmers. There are the interest connections between countryside and agriculture at the level of industrial development, the element exchanges between agriculture and farmers at the level of input/output, and the same pursuits between farmers and countryside at the level of environmental demand. They mean rural human settlement environment demands that the cultivated land use should not be degraded of ecological environment, agricultural sustainable development has set up green and efficient resource saving conditions for the cultivated land use, and farmers’ life needs and welfare guarantee promote the intensification of management through the transformation of production and life style.
SICLU will help cement the foundation of agriculture, foster a new type of professional farmers, fodder system for sale make rural areas more livable, and ultimately form a new development pattern featuring efficient agriculture, rich farmers and beautiful countryside. In response to the relationship between goals and connotations of SICLU. 1) Intensive management, high yield efficiency and resource saving can all optimize economic benefit. Resource saving, non-degradation of the ecological environment and intensive management can all guarantee ecological benefit. High yield efficiency, resource saving, non-degradation of the ecological environment and social sustainability can all enhance social benefit. 2) SICLU is to balance and optimize the comprehensive benefits of economy, ecology, and society in order to identify the optimal solution and maintain a long-term stable dynamic balance. The higher level of SICLU is not the maximization of the five connotations simultaneously, but the maximization of the comprehensive benefits and the maintenance of a dynamic balance. It is difficult to achieve the optimal solution of ecological, economic and social benefits by placing too much emphasis on one or several aspects while ignoring other aspects. Cultivated land is the important livelihood capitals of farming households.Differences in the use behaviors of farming households are the main factors affecting the SICLU. The farming households’ livelihood transition is a long-term gradual evolution process from a traditional agricultural livelihood type to non-agricultural or agricultural specialization. In this process, the external environment and resource endowment of cultivated land affect the direction of farming households’ livelihood transition by influencing the accumulation and survival of farming households’ livelihood capitals.
Livelihood transition will indirectly change farming households’ cultivated land dependence and land consciousness, affect cultivated land use behaviors, and then affect the level of SICLU, and feedback the progress of farming households’ livelihood transition. In terms of SICLU connotations, farming households are “Economic Man” of bounded rationality, they are more inclined to pursue the maximization of short term interests, and are willing to pay more attention to the economic benefit of cultivated land use, and tend to ignore the ecological benefit and social benefit. That is to say, in the process of direct cultivated land use in pursuit of high yield efficiency through the means of intensive management, farming households indirectly assume the responsibility of resource conservation and non-degradation of ecological environment, and make contributions to social food security and sustainable resource protection. Energy is involved in the structure and function of the entire cultivated land use, among which solar energy is the basis of all forms of energy on Earth. Each farming household belongs to a relatively independent cultivated land use system , and the emergy analysis can cover most input sources and material outputs in the process of cultivated land use by farming households. Therefore, considering each farming household as one unit, by converting different concepts, categories, energy levels, and other incomparable energies and materials into the same standard solar emergy, a SICLU evaluation can be performed. It is helpful to quantitatively analyze the complex energy, material, currency, and information flow in the complex system of nature economy-society in order to quantitatively measure the structural and functional characteristics of cultivated land use and more comprehensively and objectively measure the ecological, economic, and social benefits of cultivated land use dominated by different household livelihood types . The energy inputs of cultivated land use mainly include renewable environmental resources, non-renewable environment inputs, nonrenewable industrial auxiliary energy, and renewable organic energy.
Accompanied by inevitable waste and losses , part of the energy entering the system is stored in the topsoil, most of which participates in cultivated land use and is converted into crop energy . Another part of the energy is stored by seed retention, straw turnover, and other methods. Most agricultural crops enter the economic market to gain profits, which are used to purchase new non-renewable auxiliary industrial energy and renewable organic energy for use in the next production cycle. With reference to related emergy analysis research and the representation of emergy computation in Emergy Analysis of Ecological Economic System by Lan Shengfang et al, the materials, energy, and services involved in the inputs and outputs of cultivated land use can be converted into solar emjoules according to Equations – . According to the statistics, 333 farming households in the sample made use of cultivated land in 2019. According to the emergy overview of the cultivated land use of 333 farming households , the renewable environmental resources mainly included rainwater chemical energy and earth rotational energy. The energy of non-renewable topsoil lost was relatively low because the soil texture is mostly cinnamon soil, and soil erosion is generally due to mild or moderate water erosion in Qufu County. The auxiliary inputs obtained by purchase were obviously higher. They were the most important input sources in cultivated land use, as compared with the environmental inputs obtained free of charge. Specifically, the non-renewable industrial auxiliary inputs primarily included the inputs of increasing production and saving labor, while renewable organic auxiliary inputs were mainly the increasing production inputs.
The non-renewable industrial auxiliary inputs, which mainly consisted of fertilizer, mechanical power, and pesticides, were higher than that of renewable organic inputs, which primarily included labor, straw, and seeds. Regarding non-renewable industrial auxiliary inputs, the fertilizer and machinery were relatively higher, whereas for organic auxiliary inputs, the labor and straw were higher. In terms of agricultural output, the outputs of grain crops were significantly higher than that of cash crops. In addition, auxiliary inputs inevitably produces waste in the process of cultivated land use, thereby reducing its use efficiency. Fertilizers and pesticides were the main sources of waste loss. According to the SICLU evaluation system, it is assumed that the SII is approximately 2.38 when the five criterion indices reach a maximum of 1. However, it is difficult to reach this the level in actual cultivated land use. With the above theoretical analysis of SICLU, there are checks and balances and coordination among the five connotations. For example, high-efficiency output is the most direct purpose of farming households’ cultivated land use, and intensive management is the desirable main method to obtain high-yield output under existing resource conditions, which can be embodied via changes in input structure and cultivated land use management, as well as changes in the degree of ecological environment interference and the impact on social and economic development. Regarding inputs, an increase in the management intensive criterion index indicates an increase in the artificial auxiliary inputs, wherein the increase in material inputs is the most direct. Meanwhile, an increase in industrial auxiliary inputs indicates an increase in non-renewable inputs and waste loss, causing negative impacts on resource savings and the ecological environment. If the two criterion indices of resource savings and non-degradation of ecological environment are increased while the external natural environment remains unchanged, it is necessary to reduce the auxiliary inputs applied externally, which will weaken the criterion index of high yield efficiency, further affecting the criterion index of social sustainability. Therefore, it is necessary to lower the industrial auxiliary inputs and increase renewable organic function inputs. However, the industrial auxiliary inputs cannot be lowered on a large scale because of its irreplaceable nature in agricultural production. In addition, reducing the inputs of pesticides, chemical fertilizers, and even agricultural machinery means that more labor inputs are required, thereby reducing cultivating efficiency and affecting the criterion index of management intensification.
Therefore, because of the actual use of cultivated land and the coordination and balance among the SICLU connotations, the criterion indices cannot reach their maxima simultaneously, fodder growing system which is consistent with the law of diminishing marginal returns. This is consistent with the purpose of SICLU that is not to simultaneously maximize the ecological, economic, and social benefits, but to obtain a solution that maintains a dynamic balance in order to maximize the compound benefits. In addition, differences exist in not only the SII values but also the internal structure among the non-SI, low-SI, medium-SI, and high-SI. The SII structures summarized in Table 3 reveal the average value of the criterion indices under different SICLU levels. Note that its pentagon has a somewhat regular shape, while the pentagons formed by each individual farming household have more abnormal shapes. The irregular pentagons also verify the checks and balances and coordination among the five connotations. Nevertheless, they effectively reflect differences in cultivated land use under different SII values. Assuming that the SI levels of the sample farming households are in a dynamic process of continuous improvement, it can be speculated that the SICLU evolved from intensive dominance to sustainable dominance as development changed from low to high levels. These results demonstrated substantial economic benefit, but the ecological benefit and social benefit remain in their early stages. With increasing SICLU, economic benefit growth will slow and even stagnation, ecological benefit and social benefit will begin to appear until a relative equilibrium is reached. According to the SICLU evaluation structure of the sample farming households with different farming households’ livelihood types , the average values of SIY’ and SIM’ were high, followed by the SIR’, SIE’, and SIS’. In particular, the average value SIY’ of agricultural professional farming households was significantly higher than the others, the average values of SIM’ and SIS’ were relatively higher, and the SIE’ and SIR’ were significantly lower, revealing an obvious imbalance. The relatively higher SII can primarily be attributed to the contribution of SIY’. Theoretically, these results denote an intensive and low sustainable model, but this may not be the case in practice. Because the agricultural-professional farming households had a large management scale, a high degree of agricultural mechanization, high farming efficiency and agricultural productivity, and lower labor inputs, as compared with the other types, it can achieve lower renewable organic inputs, and higher non-renewable and environmental load ratios, making its average value of SIE’ relatively low. Moreover, although the SIE’ value was relatively low, there was a strong correlation between SIS’ and SIY’ and SIE’, and the SIS’ was relatively high because of the high SIY’. However, agricultural-professional farming households had lower SIR’ than other farming household types, indicating that their dependence on non-renewable resources was still strong. This may also explain why the cultivated land use of agricultural-professional farming households were mostly at a medium-SI level, not a high-SI level. The SIE’ and SIR’ could be improved by improving the proportional relationship of inputs, moderately reducing the inputs of non-renewable resources, such as chemical fertilizers and pesticides, and increasing the renewable ratio by reducing non-renewable auxiliary inputs. However, for agricultural-professional farming households, agricultural income is the main source of family earnings and main purpose. Thus, although their dependence on cultivated land was the strongest, their consciousness of land protection was weaker than that of traditional agricultural farming households.