Rice sustainable production area planning model based on agricultural crop rotation fallow

Abstract

The invention discloses a rice sustainable production area planning model based on agricultural crop rotation fallow, the model is a rice sustainable production area planning model based on agricultural crop rotation fallow, and a creation method of the model comprises the following steps: performing field investigation and survey of a farm, investigation and survey of rice production data, carrying out questionnaire survey to collect detailed information of material and energy input and output in the whole production process in different farm rice production systems, and taking the detailed information as life cycle evaluation background data; evaluating and quantifying the environmental influence of the rice production system of the rice farm by adopting life cycle; a rice sustainable production multi-objective optimization model is built, wherein an environmental influence quantification method, a subsidy willingness quantification method and multi-objective optimization are adopted; the rice sustainable production area planning model based on agricultural crop rotation fallow strives to carry out grain production in the balance of environmental sustainability, economic sustainability and social sustainability, and provides a basis for agricultural sustainable development.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural planning models, and in particular to a rice sustainable production area planning model based on agricultural rotation and fallow. Background Art

[0002] With the breakthroughs and development of science and technology, conventional agriculture, characterized by high input and high efficiency, has made great contributions to world food production, economic development and social stability, but it has also brought with it increasingly obvious problems such as environmental pollution, resource depletion and biodiversity crisis.

[0003] Multi-objective optimization has been widely used in agricultural production planning, layout and structural adjustment. It can be divided into farm scale and macro scale according to the scale of the research sample. In addition to being used for actual production guidance, the FarmDESIGN model focusing on the farm scale has also been used to optimize the production structure of two Vietnamese planting farms from the perspectives of society, nutrition and economy, and analyze the synergy and trade-off between sustainability indicators to improve farmers' lives, expanding the research perspective of multi-objective planning. Current research on the macro-regional scale mainly optimizes agricultural layout and structure from the perspectives of resource consumption and environmental impact in the agricultural production process. Some studies have constructed a multi-objective energy planning model from the perspective of agricultural renewable energy systems to balance economy and energy efficiency, but in the process of constructing the optimization model, they focus on a certain type of energy in the agricultural production process and ignore the integrity of the system. In addition, some scholars have combined multi-objective planning with comprehensive perspectives such as food, water resources, carbon emissions, energy, and land resources to study the regional scale agricultural structure layout. At present, decision-making objectives and constraints in the research on the optimization of agricultural production system structure are gradually tending to cover a more comprehensive energy and resource consumption system to achieve the goal of sustainable agricultural development. Some studies have also conducted optimization from a more comprehensive perspective, including factors such as grain output, income, and the amount of fertilizer and pesticide applied. However, the environmental impact is only represented by the amount of fertilizer and pesticide applied. The impacts of fuel, electricity consumption, and pollutant emissions during field production have not been taken into account. Agricultural subsidies, a key factor in agricultural production, have not been comprehensively considered either.

[0004] The environmental impacts of rice, wheat and green manure cultivation mainly come from the environmental emissions from the application of fertilizers and pesticides, the environmental emissions from diesel combustion and the depletion of water resources. At the same time, the development area of ​​arable land is greatly limited. In addition, as an inherently weak industry, the economic benefits of agriculture are often affected by the external environment. In order to solve these three major problems, how to plan the planting structure within the limited arable land area to generate the highest economic benefits and bring the least environmental impact.

[0005] The present invention provides a rice sustainable production area planning model based on agricultural rotation and fallow, striving to produce food in a balance between environmental sustainability, economic sustainability and social sustainability, and providing a basis for sustainable agricultural development. Summary of the invention

[0006] The purpose of the present invention is to provide a rice sustainable production area planning model based on agricultural rotation and fallow, striving to produce food in a balance between environmental sustainability, economic sustainability and social sustainability, and providing a basis for sustainable agricultural development.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A rice sustainable production area planning model based on agricultural rotation and fallow, the model is a rice sustainable production area planning model based on agricultural rotation and fallow, and the creation method of the model comprises the following steps:

[0009] (1) Research plan and data acquisition: Conduct field research on farms, investigate rice production data, and use questionnaires to collect detailed information on the material and energy inputs and outputs of the entire production process in rice production systems on different farms as background data for life cycle assessment (LCA);

[0010] (2) Life cycle assessment: The life cycle assessment (LCA) method is used to quantify the environmental impact of rice production systems on rice farms:

[0011] S1. Determination of research objectives, system boundaries and functional units;

[0012] S2. Inventory analysis: By deconstructing the input-output information of the production process obtained through the survey, the material and energy consumption and substance emissions involved in the production process are extracted and summarized in the form of a data list;

[0013] S3. According to the characteristics of rice, wheat and green manure planting, five closely related environmental impact categories were selected and characterized using the ReCiPe2016(H)v1.02 method. The emissions corresponding to different environmental impact categories were multiplied by their respective characterization coefficients and finally summed up, as shown in Formula 1;

[0014]

[0015] Among them, E i is the characterization value of environmental impact type i; x is the emission of each substance in the emission inventory; CF x is the characterization factor;

[0016] All environmental impact levels are added together to quantify the comprehensive environmental impact, and then standardized using the 2010 world per capita environmental impact standardized coefficient based on the ReCiPe model method. The specific approach is: each environmental impact result is divided by the standardized coefficient, as shown in Formula 2;

[0017] N i =E i / NF i (Formula 2);

[0018] Among them, N i is the standardized result of environmental impact category i; NF i is the standardized coefficient of impact category i;

[0019] (3) Construction of a multi-objective optimization model for sustainable rice production:

[0020] a. Environmental impact quantification method: adopt the life cycle calculation method to quantify the environmental impact level through characterization results;

[0021] b. Quantification method of subsidy willingness: using the selection experiment method to quantify farmers' willingness to accept crop rotation and fallow subsidies through marginal benefits;

[0022] c. Multi-objective optimization: Multi-objective optimization includes two parts: constructing the objective function and setting the constraints. There are at least two objective functions, and there is an opposing balance relationship between the decision variables. The constraints need to be set according to the characteristics of the research sample and actual needs. There is no specific quantity requirement. Multiple constraints designed according to actual conditions usually appear in the form of a series of inequalities. The objective function is shown in Formula 3.

[0023] T=∑ i a i × i (Formula 3);

[0024] Among them, x i represents the value of the decision variable; a i represents the objective function value;

[0025] Based on this, the objective function is set based on the three sustainable development goals of economy, environment and society as follows:

[0026] The economic benefit target is shown in Formula 4;

[0027] maxf 1 (x i )=∑ i a i × i (Formula 4);

[0028] The environmental benefit target is shown in Formula 5;

[0029] minf 2 (xi) = ∑ i b i ×x i (Formula 5);

[0030] The social benefit objective is as shown in Formula 6;

[0031] minf 4 (x i ) = ∑ i c i ×x i (Formula 6);

[0032] Among them, x i represents the production area of various rice production systems; a i , b i , c i represent the objective function values of rice, wheat, and green manure production activities.

[0033] Preferably, the background data of the life cycle assessment method (LCA) includes detailed information on agricultural farming and detailed information on agricultural input. The detailed information on agricultural farming includes: the time of plowing, sowing, harvesting, and irrigation, fuel consumption, power consumption, and agricultural machinery type information; the detailed information on agricultural input includes fertilizer, pesticide type, origin, application rate, and application form information, as well as detailed information on the transportation of agricultural inputs and agricultural products.

[0034] Preferably, the indicators of the environmental impact category include: the Global warming indicator measured in CO 2 equivalent, the Water consumption indicator, the Freshwatereutrophication indicator, the Terrestrialacidification indicator, and the Freshwater ecotoxicity indicator.

[0035] Preferably, in the step S1, the research objective is the environmental impact of the rice production system per unit area, and the environmental impacts generated per unit area of different rice production systems under different subsidy conditions are compared.

[0036] Preferably, in the step S1, the system boundary is set as the process from the extraction of raw materials for agricultural input production to the completion of agricultural product production and output to the market.

[0037] Preferably, in the step S1, the functional unit is set as the area of 1 hectare of rice planting system.

[0038] Due to the application of the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0039] 1. The rice sustainable production area planning model based on agricultural rotation and fallow of the present invention is based on existing subsidies and is evaluated and optimized through field survey data. It is closely linked to the actual situation and can provide a certain scientific basis for subsidy optimization;

[0040] 2. The rice sustainable production area planning model based on agricultural rotation and fallow of the present invention strives to produce food in a balance between environmental sustainability, economic sustainability and social sustainability, providing a basis for sustainable agricultural development. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, some of the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be made based on these drawings without paying any creative work.

[0042] Figure 1 This is a system boundary diagram of the rice annual planting system according to Embodiment 1 of the present invention;

[0043] Figure 2 This is a schematic diagram of a multi-objective optimization model for sustainable rice production according to Example 1 of the present invention;

[0044] Figure 3 This is a comprehensive index diagram of environmental impact of a rice planting system according to Example 1 of the present invention;

[0045] Figure 4 It is a planting area flow diagram of the optimization scheme of Example 1 of the present invention;

[0046] Figure 5 1 is a comparison diagram of the environmental impact of the optimization solution of Example 1 of the present invention and the prior art;

[0047] Figure 6 It is the prior art, optimization plan and target output, total subsidy amount and economic profit diagram of Example 1 of the present invention. DETAILED DESCRIPTION

[0048] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, a specific implementation scheme is now described in detail.

[0049] The present invention is further described below in conjunction with the embodiments, but the present invention is not limited to the following embodiments. The implementation conditions used in the embodiments can be further adjusted according to the different requirements of specific use, and the implementation conditions not indicated are conventional conditions in the industry. The technical features involved in each embodiment of the present invention can be combined with each other as long as they do not conflict with each other.

[0050] Example 1

[0051] See attached Figure 1-6 This embodiment provides a rice sustainable production area planning model based on agricultural rotation and fallow. The model is a rice sustainable production area planning model based on agricultural rotation and fallow. This embodiment takes the rice rotation and fallow subsidy system in Suzhou as an example to conduct a sample survey of the rice planting system in Suzhou in 2021. It includes all rice farming systems involved in the rotation and fallow subsidy system, including unsubsidized farms: 21 conventional rice and wheat (CRW), green manure subsidized farms: 7 conventional rice and green manure (CRG), 9 organic rice and green manure (ORG), fallow subsidized farms: 9 conventional rice fallow (CRF), 15 organic rice fallow (ORF); the model creation method includes the following steps:

[0052] (1) Research plan and data acquisition: The basic information of organic farms was obtained through the China Food and Agricultural Product Certification Information System. The farms were preliminarily selected based on the following conditions: obtaining organic (non-conversion period) product certification and the rice production area of ​​the farm was greater than 2 hectares. Field research was conducted on the farms to investigate rice production data. Questionnaire surveys were conducted to collect detailed information on the material and energy inputs and outputs of the entire production process in the rice production system of different farms as background data for the life cycle assessment (LCA). The life cycle assessment (LCA) background data included detailed information on farming operations and detailed information on agricultural inputs. The detailed information on farming operations included: time for tilling, sowing, harvesting and irrigation, fuel consumption, electricity consumption and type of agricultural machinery. The detailed information on agricultural inputs included information on fertilizer and pesticide types, origin, application amount and application form, as well as detailed information on the transportation of agricultural inputs and agricultural products.

[0053] (2) Life cycle assessment: The life cycle assessment (LCA) method is used to quantify the environmental impact of rice production systems on rice farms:

[0054] S1. Determination of research objectives, system boundaries and functional units:

[0055] The purpose of crop rotation and fallow subsidies is to reduce the overall environmental impact of the rice-centered production system, so the research target is the environmental impact of the rice production system per unit area, and compare the environmental impact per unit area of ​​different rice production systems under different subsidy conditions;

[0056] The system boundary is set as the process from the mining of raw materials for agricultural production to the completion of agricultural production and output to the market. As shown in the figure, according to the characteristics of rice, wheat and green manure production processes, the life cycle process is divided into agricultural material subsystem, farming subsystem and transportation subsystem, including three planting systems: rice and wheat rotation, rice and green manure (rapeseed, astragalus, vetch) rotation, and rice fallow. Therefore, the functional unit is set as 1 hectare of rice planting system area;

[0057] S2. Inventory analysis: By deconstructing the input-output information of the production process obtained from the survey, the material and energy consumption and substance emissions involved in the production process are extracted and summarized in the form of a data list. This process is completed in SimaPro9.0;

[0058] The core of the inventory analysis is to summarize the material input-output data of the rice, wheat and green manure production processes in each subsystem and decompose each process link to prepare for the impact assessment process. The size of the farm cultivated area and the main input-output situation under various subsidy levels are shown in Table 1.

[0059] Table 1

[0060]

[0061]

[0062] The emission data of fertilizer, chemical fertilizer and seed production process in the agricultural materials subsystem are from Ecoinventv3.5 and Agri-footprintv4.0. The database lacks the inventory data of rapeseed cake, sheep manure and biogas slurry production, and the corresponding data are obtained through literature retrieval to supplement it. The application type of rapeseed cake is fermented rapeseed cake, and the inventory data can be calculated through the biodiesel fermentation process. The sample sheep manure application is produced by Taicang Xinke Ecological Technology Co., Ltd., with 1 ton of sheep manure organic fertilizer as the functional unit. The system boundary is set from cradle to processing plant gate, and the research results of Shen Yuan et al. on its production process and environmental emissions are combined to model it. The biogas slurry application farm uses pig manure and cow manure as raw materials for fermentation, and it is modeled in combination with the research results of Wang Xiaolong.

[0063] The emission data of electricity consumption in the farming subsystem comes from Ecoinventv3.5. Rice production consumes a lot of water, so ET0 (ET0 calculator version3.1) is used to calculate the water resource consumption in the rice production process. Since the research target is the entire rice production system, the data of water demand for soaking fields and field leakage outside rice planting are also included. The calculation method refers to the research of Li Dianshan et al. Since it is difficult to obtain the specific model of irrigation equipment during the farm survey, the irrigation power consumption refers to the research results of Youtao C. et al. The diesel combustion inventory data for electricity consumption comes from GaBiDatabase, using the DNDC9.5 (DeNitrification-DeComposition9.5) model. The carbon and nitrogen field emissions during the crop production process were simulated. The phosphate emission data generated by the application of phosphate fertilizers were calculated based on the reference data. The heavy metals (As, Cd, Cr, Cu, Hg, Pb and Zn) introduced into the soil by fertilizer application were also quantified. The fertilizers that caused heavy metal residues in the research samples included chemical fertilizers: compound fertilizers, urea; organic fertilizers: rapeseed cake, commercial organic fertilizers, kitchen organic fertilizers, pig manure, sheep manure, cow manure, poultry manure and biogas slurry; the application of pesticides caused pollutants to be discharged into the soil, atmosphere and water bodies. The pollutant residues were calculated as pesticides based on 43%, 10 and 1% of the active ingredients of the applied pesticides;

[0064] S3. Select five closely related environmental impact categories based on the characteristics of rice, wheat and green manure planting: long-term flooding of rice fields, CH 4 and NO 2 Greenhouse gas emissions are obvious, so we choose to use CO 2 The global warming index is measured in terms of CO 2 Rice production also consumes a lot of freshwater resources, so the water consumption indicator is selected; the fertilizer input during rice, wheat and green manure planting will cause a large amount of nutrients to enter the water body, so the freshwater eutrophication indicator is selected and quantified by P equivalent; the diesel combustion during the operation of agricultural machinery during farming will produce a large amount of NH 3 、NO x and SO 2 Therefore, the terrestrial acidification indicator was selected, and SO 2The destructiveness of chemical pesticides to the ecosystem cannot be ignored and has also been a hot topic in recent years. Therefore, the freshwater ecotoxicity index 1, 4-DCB equivalent quantification was selected and characterized using the ReCiPe2016(H)v1.02 method. The emissions corresponding to different environmental impact categories were multiplied by their respective characterization coefficients and finally summed up, as shown in Formula 1.

[0065]

[0066] Among them, E i is the characterization value of environmental impact type i; x is the emission of each substance in the emission inventory; CF x is the characterization factor;

[0067] All environmental impact levels are added together to quantify the comprehensive environmental impact, and then standardized using the 2010 world per capita environmental impact standardized coefficient based on the ReCiPe model method. The specific approach is: each environmental impact result is divided by the standardized coefficient, as shown in Formula 2;

[0068] N i =E i / NF i (Formula 2);

[0069] Among them, N i is the standardized result of environmental impact category i; NF i is the standardized coefficient of impact category i;

[0070] (3) Construction of a multi-objective optimization model for sustainable rice production:

[0071] By constructing a multi-objective optimization model for sustainable rice production, such as Figure 2 As shown, explore the path to maximize the environmental, economic and social benefits of rice production, adjust the production area ratio of various rice planting systems in Suzhou in combination with the characteristics of various rice planting systems, so as to reasonably allocate the area of ​​Suzhou's five types of rice planting systems: conventional rice-wheat rotation, conventional rice-green manure rotation, conventional rice fallow, organic rice-green manure rotation, and organic rice fallow. Achieve the goals of maximum total rice and wheat production, maximum rice and wheat returns, minimum global warming impact, minimum freshwater ecotoxicity impact, and minimum environmental acidification impact;

[0072] a. Environmental impact quantification method: adopt the life cycle calculation method to quantify the environmental impact level through characterization results;

[0073] b. Quantification method of subsidy willingness: using the selection experiment method to quantify farmers' willingness to accept crop rotation and fallow subsidies through marginal benefits;

[0074] c. Multi-objective optimization: Multi-objective optimization includes two parts: constructing the objective function and setting the constraints. There are at least two objective functions, and there is an opposing balance relationship between the decision variables. The constraints need to be set according to the characteristics of the research sample and actual needs. There is no specific quantity requirement. Multiple constraints designed according to actual conditions usually appear in the form of a series of inequalities. The objective function is shown in Formula 3.

[0075] T=∑ i a i × i (Formula 3);

[0076] Among them, x i represents the value of the decision variable; a i represents the decision variable; x i Represents the objective function value;

[0077] Based on this, the objective function is set based on the three sustainable development goals of economy, environment and society as follows:

[0078] The economic benefit target is shown in Formula 4;

[0079] minf 1 (x i )=∑ i a i × i (Formula 4);

[0080] The environmental benefit target is shown in Formula 5;

[0081] minf 2 (x i )=∑ i b i × i (Formula 5);

[0082] The social benefit target is shown in Formula 6;

[0083] minf 4 (x i )=∑ i c i × i (Formula 6);

[0084] Among them, x i represents the production area of ​​each rice production system; a i , b i , and c i represents the objective function values ​​of rice, wheat and green manure production activities;

[0085] The comprehensive index of environmental impact of rice planting system is as follows Figure 3 As shown in the figure, the planting area flow diagram of the optimization scheme is as follows Figure 4 The optimization plan for sustainable rice production planting area is shown in Table 2.

[0086] Table 2

[0087]

[0088]

[0089] From the perspective of environmental sustainability Figure 5 As shown in the figure, after the planting optimization, the environmental impact of rice production has been improved, and the overall sustainable development target requirements have been met. On average, the overall environmental impact index has dropped by 10.5% compared with the current level. Among them, the environmental impact of the unsubsidized CRW has been reduced by 14.2% after optimization, and the overall environmental impact of the subsidized system has increased (18.2%) compared with the current level, mainly due to the increase in the area of ​​ORF, and its environmental impact index is 5.2 times the current level. In contrast, the environmental impact of CRG (60.7%), CRF (16.0%) and ORG (15.3%) has improved compared with the current situation. From the perspective of fertilizer and pesticide application, the total nitrogen application of fertilizer in the optimized planting plan is 23,000 tons, a decrease of 15.6% from 2021. There is also a significant improvement in the reduction of pesticides. With the optimized planting plan, the amount of pesticide application will be 15.3% lower than the 2025 development target. After optimization, the application of pesticides and fertilizers is still concentrated in the CRW system, of which the total fertilizer nitrogen input is 21,000 tons, accounting for 90.8% of the total nitrogen input of the optimization scheme, and the total pesticide input is 272.4 tons, accounting for 92.2% of the total input. After CRG and CRF optimization, the fertilizer nitrogen input was reduced by 484.3 tons and 346.4 tons, respectively, and the pesticide input was reduced by 4.7 tons and 3.8 tons.

[0090] Social sustainability Figure 6 As shown in the figure, the total planned grain output (rice and wheat) is 757,000 tons. Although it is 8.7% lower than the current output, it can achieve the 2025 food security goal (399 kg of grain per capita), exceeding the future development goal by 8.0%. Compared with the current situation, except for ORF, the total output of other planting systems has decreased. The total output of ORF has increased by 53,000 tons, which is 3.4 times the current output. The total output of other planting systems has decreased by 2,000-104,000 tons, which is 14.2-60.7% lower than the current output. In terms of the investment in crop rotation and fallow subsidies, the amount of the optimized plan is 1.5 times the current amount. In the optimized plan, ORF has increased by 36 million yuan compared with the current situation, and CRG, CRF and ORG have decreased by 1-0.06 million yuan.

[0091] Economic sustainability Figure 6As shown in the figure, the total profit in the optimized solution reached 1.36 billion yuan, an increase of 2.7% over the current profit. The increase in the proportion of organic production can bring greater economic benefits. The total profit of ORF in the optimized solution is 280 million yuan, 1.5 times the current situation, and 230 million yuan more than the current total profit. The one with the largest reduction in total profit is CRW, which is 150 million yuan lower than the current situation.

[0092] If you want to achieve higher environmental sustainability, Plan 2, Plan 3, Plan 4, Plan 5 and Plan 6 are recommended; if you want to achieve higher food yields, Plan 1, Plan 10, Plan 9, Plan 8 and Plan 7 are recommended; if lower expenditure is the goal, Plan 1, Plan 10, Plan 9, Plan 8 and Plan 5 are recommended; if you want to achieve higher economic profits, Plan 1, Plan 2, Plan 3 and Plan 4 are recommended.

[0093] In summary, the sustainable rice production area planning model based on agricultural rotation and fallow of the present invention is based on existing subsidies, and is evaluated and optimized through field survey data. It is closely linked to the actual situation and can provide a certain scientific basis for subsidy optimization. The sustainable rice production area planning model based on agricultural rotation and fallow of the present invention strives to produce food in a balance between environmental sustainability, economic sustainability and social sustainability, and provides a basis for sustainable agricultural development.

[0094] The above-mentioned embodiment only expresses one implementation mode of the present invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A rice sustainable production area planning model based on agricultural rotation and fallow, characterized in that: The model is a rice sustainable production area planning model based on agricultural rotation and fallow, and the creation method of the model includes the following steps: (1) Research plan and data acquisition: Conduct field research on farms, investigate rice production data, and use questionnaires to collect detailed information on the material and energy inputs and outputs of the entire production process in rice production systems on different farms as background data for the life cycle assessment method; (2) Life cycle assessment: The environmental impact of rice production systems on rice farms is quantified using the life cycle assessment method: S1. Determination of research objectives, system boundaries and functional units; S2. Inventory analysis: By deconstructing the input-output information of the production process obtained through the survey, the material and energy consumption and substance emissions involved in the production process are extracted and summarized in the form of a data list; S3. Select five closely related environmental impact categories according to the characteristics of rice, wheat and green manure planting, and characterize them. Multiply the emissions corresponding to different environmental impact categories by their respective characterization coefficients, and finally sum them up, as shown in Formula 1; Among them, E i is the characterization value of environmental impact type i; x is the emission of each substance in the emission inventory; CF x is the characterization factor; All environmental impact levels are added together to quantify the comprehensive environmental impact, and then standardized using the 2010 world per capita environmental impact standardized coefficient based on the ReCiPe model method. The specific approach is: each environmental impact result is divided by the standardized coefficient, as shown in Formula 2; N i =E i / NF i (Formula 2); Among them, N i is the standardized result of environmental impact category i; Ei is the characterization value of environmental impact type i; NF i is the standardized coefficient of impact category i; (3) Construction of a multi-objective optimization model for sustainable rice production: a. Environmental impact quantification method: adopt the life cycle calculation method to quantify the environmental impact level through characterization results; b. Quantification method of subsidy willingness: using the selection experiment method to quantify farmers' willingness to accept crop rotation and fallow subsidies through marginal benefits; c. Multi-objective optimization: Multi-objective optimization includes two parts: constructing the objective function and setting the constraints. There are at least two objective functions, and there is an opposing balance relationship between the decision variables. The constraints need to be set according to the characteristics of the research sample and actual needs. There is no specific quantity requirement. Multiple constraints designed according to actual conditions usually appear in the form of a series of inequalities. The objective function is shown in Formula 3. T=∑ i a i × i (Formula 3); Among them, x i represents the value of the decision variable; a i represents the objective function value; Based on this, the objective function is set based on the three sustainable development goals of economy, environment and society as follows: The economic benefit target is shown in Formula 4; maxf1(x i =∑ i a i × i (Formula 4); The environmental benefit target is shown in Formula 5; minf2(x i )=∑ i b i × i (Formula 5); The social benefit target is shown in Formula 6; minf4(x i )=∑ i c i × i (Formula 6); Among them, x i represents the production area of ​​each rice production system; a i , b i and c i Represents the objective function values ​​of rice, wheat and green manure production activities.

2. A rice sustainable production area planning model based on agricultural rotation and fallow as claimed in claim 1, characterized in that: The background data of the life cycle assessment method includes detailed information on farming practices and agricultural inputs; The detailed farming information includes: time of tilling, sowing, harvesting and irrigation, fuel consumption, electricity consumption and type of agricultural machinery; Detailed information on agricultural inputs includes information on fertilizer and pesticide types, origin, application amount and application form, as well as detailed information on the transportation of agricultural inputs and agricultural products.

3. The rice sustainable production area planning model based on agricultural rotation and fallow as claimed in claim 1, characterized in that: The indicators of the environmental impact category include: global warming indicators measured by CO2 equivalent, water resource consumption indicators, freshwater eutrophication indicators, terrestrial acidification indicators, and freshwater ecotoxicity indicators.

4. The rice sustainable production area planning model based on agricultural rotation and fallow as claimed in claim 1, characterized in that: In step S1, the research target is the environmental impact of the rice production system per unit area, and the environmental impact per unit area of ​​different rice production systems under different subsidy conditions is compared.

5. The rice sustainable production area planning model based on agricultural rotation and fallow as claimed in claim 1, characterized in that: In step S1, the system boundary is set to the process from the mining of raw materials for agricultural production to the completion of agricultural product production and output to the market.

6. The rice sustainable production area planning model based on agricultural rotation and fallow as claimed in claim 1, characterized in that: In step S1, the functional unit is set to 1 hectare of rice planting system area.

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