Research On The Quality Evaluation Of Agricultural Land And Food Security

The quantity and quality of agricultural land directly reflect a country's basic national condition and its resource natural endowment. It is the origin of clothing and food, the foundation of development, the most foundamental condition of food security as well.In 1994, Lester Brown, the chairman of American World's Abservation Research Institute, had published a research report,"Who will feed China:wake-up call for a small planet"which caused a worldwide deputation and intense repercussion. From there, the question of China's food safety had been the focus in theoretical communities, academic communities, and the different countries of the world. To some extent, in the long period, China's society problems and crises are directly related to the large population and shortage of land, especially the cultivated land resources. But ensurence of China's food security must rely on china itself. Therefore,"protecting cultivated land is protecting our lives."The food security issue includes two contents of the of cultivated land quantity security and cultivated land quality security. But its sore lies in ensuring the capability of comprehensive food production. China had accomplished the current landuse survey in the whole country from 1982 to 1996, got the knowledge of land quantity and rights condition. But the evaluating research of agricultural land which based on the natural, social and economical conditions to evaluate comprehensively the farming land quality has been detained and fallen behind, and the agricultural land evaluation researches mainly focus on the single evaluation methods,such as land suitability evaluation, economical evaluation, etc. Comprehensive evaluation researches are relatively few. As foundation, it is much fewer to research the possibility boundary of food supply by studying the capability of comprehensive food production. They are mainly interest in studying on the ordinary food polices, buying or selling system, market supply and demand, price analyses, yield prediction,etc. This paper has studied the theories and methods of comprehensive agricultural land evaluation systematically from the beginning of the agricultural land evaluation research. By establishing the relationship between agricultural land quality and its food comprehensive production capability, it predicted and studied the boundary of food security ensurence.The disquisition is divided into 2 parts of agricultural land evaluation and food security. Part 1 discus comprehensively the research purpose and significance, background, basic thoreies, domestic and foreign research development and trendency, research content and method, main innovation achievements, etc. As a example based Sichuan province situation, this paper analyzed systematically Sichuan provincial agricultural land grading methods, established agricultural land grades system of Sichuan provincial agricultural land, and studied in detail the distribution of law of the agricultural land grades. Then, it studied the food security of Sichuan province.I. Main content and conclusion1. Analyzing and summarizing the evaluation theory and ways of agricultural land in and out of China by the numbers, establishing the techno-way for geoponic land classify in Sichuan province. The quality evaluation of geoponic land mainly bases on natural produce capacity, contemporarily combined geoponic land classification with fitness estimate and social economy evaluation. Calculating the light and caloric production of certain plants by the condition of light and caloric; evaluating the theoretic production of concerned plants by land conditions; counting the general land theoretic yield under the standard cultivation system, evaluating the land potential classification; accomplishing the land quality classify according to modifying the land use efficiency; realizing the land economy evaluation by modifying the put in and out level. Making the classify result to be comparable by taking the macroscopic command and gradual modification techno-way to classify geoponic land.2. The research adjusts the standard cultivate system zone in Sichuan province: this research studies on the standard cultivate system zone by the definition, method, index and so on, compartmentalizing the Sichuan province to be 5 standard cultivate zone ,as basin plain, basin hill, basin mountain , mountain in southwest of Sichuan and altiplano in northwest of Sichuan.3. Study the theoretic ways to select factors and proportion in geoponic classify, put forward introducing factors, such as agrocircumstance geochemistry, height above sea level, set up the geoponic classify factor system for Sichuan province. Analyze the factors that affect the quality of geoponic land, confirming the factor system and proportion of factor in the system, and classifying and measuring these factors.4. Summarize the methods applying in geoponic land classify, such as superposition method, plot method, sifting land polygon means, dynamic grids methods. Geoponic land classify in Sichuan province congruously taking plot method。Plot method is fit in all classify types and areas. Adopting the upper methods to classify each county's classified unit and then gather as a province. Sichuan province is divided into 150571 plots.5. Study the theory and method of index on light and caloric production, the natural quality proportion, and coefficient of output, land-use coefficient, land economy coefficient. Establish the parameter for geoponic land classifying, resolving the borderline join matter in county and city, ensure the dimensional continuity of classify result.6. Evaluate the quality of geoponic land in Sichuan province roundly and scientifically, classify the natural quality grade, utilized grade, geoponic land grade each to 10 grades, set up the multilayer grade system of geoponic land which contain natural quality grade, utilized grade, geoponic land grade.7. Analyze the theory and technique to verify the fruit of agricultural land classification, put forwards the academic way which combined the field verification and statistics,logic verification interior , contrasted analysis exterior and reliability analysis.8. On the basis of geoponic land evaluation, researching the academic method to reckon food-production capability, applying math model to count food-production potential of Sichuan province. Evaluating the food security of Sichuan province in future 50 years according to the population increasing and food demand; counting on the max food-production capability, there will be gap between food-production yield and demand around the year of 2040 which shows that the crisis of food security and agricultural land over loading is inevitable, and correspondingly to table a proposal on the matter of agricultural land quality. One of the proposals is to ascribe the fertile agricultural land into the basal farmland protective area; two is to keep the balance between agricultural land use and complementation, realizing the dynamic equation of agricultural land quality and quantity to ensure the food-production capacity.II. The innovation and contribution1. Apply the research methods which combined theory analysis with example analysis, qualitative analysis and quantitative analysis, amount analysis and math model analysis, putting forwards the holistic and scientific tech-method system for Sichuan province farmland classify; systemically research and summary the distributing rule of the farmland quality classify in whole province, set up the farmland quality classify system in Sichuan province for the first time.2. Put forwards the new way to form land-use coefficient model though affect factor to modify land-use coefficient. The land-use coefficient got by this new method reflects the territorial economy development level and agricultural production level factually. Simultaneously, reduce the discretion of the result, intensifying the rationality and comparability.3. Put forwards the new way to count yield ratio coefficient .The yield ratio coefficient the basic potential plant of secondary area the appointment potential plant of secondary area. This method defined the yield ratio coefficient on the theory level, resolving the problem that the evaluation result can't match the distributing rule of the farmland quality, and guaranteeing the rationality of farmland evaluation result.4.Integrate the agrocircumstance geochemistry research with farmland classify evaluation research, putting forwards introducing factors as agrocircumstance geochemistry and height above sea level, set up the theory and ways of farmland classify factors system for Sichuan province.5. Put forwards the new methods based agricultural land evaluation and food production capability. Use math models to calculate the potential capacity of Sichuan provincial food production. According to predition of Sichuan provincial futural population development and food demand, predicting and evaluating the food security situation in the near 50 years late. As a principle no decline of cultivated land production capacity, getting a scientic conclusion which the cultivated land quantity must guarantee from 552.30×104 ha to 566.14×104 ha.