Editor's Note:In recent years, when the general secretary visited the local area, he made important instructions on strengthening the comprehensive utilization of saline-alkali land many times. Cultivated land is the lifeblood of grain production, saline-alkali land is an important reserve resource of cultivated land, and the comprehensive transformation and utilization of saline-alkali land is an important aspect of cultivated land protection and improvement, it is of great significance to carry out the comprehensive transformation and utilization of saline-alkali land, it is necessary to fully tap the potential of saline-alkali land development and utilization, strengthen the transformation and upgrading of existing saline-alkali cultivated land, effectively curb the trend of salinization of cultivated land, steadily expand the space for agricultural production, and improve the comprehensive agricultural production capacity.
According to the standards of the Third National Land Survey (hereinafter referred to as the "Three Adjustments") of national land, saline-alkali land refers to the land where saline-alkali accumulation on the surface layer grows natural salt-tolerant plants, and is managed as unused land. China's saline-alkali land has a large area, many types and wide distribution, and has a long history of saline-alkali land management. According to the incomplete statistics of UNESCO and FAO, the total area of saline-alkali land in China is about 1.5 billion mu, which is mainly distributed in three major areas: first, the saline-alkali land dominated by sulfate and chloride in the arid and semi-arid areas of central and western China, distributed in Xinjiang, Qinghai, Inner Mongolia, Ningxia and other places, accounting for 96 of the saline-alkali land in the country1%；The second is the carbonate-dominated soda saline-alkali land in Northeast China, which is distributed in Jilin, Inner Mongolia, Heilongjiang and other places, accounting for 32%；The third is the coastal saline-alkali land dominated by chloride on the eastern coast, which is distributed in Shandong, Jiangsu, Hebei and other places, less than 1% of the saline-alkali land in the country.
Based on the current resource conditions and technical level, and comprehensively considering the factors such as ecology, climate, soil, and location, the saline-alkali land suitable for development as cultivated land in the country at this stage is mainly distributed in Jilin, Inner Mongolia, Xinjiang, Heilongjiang and other provinces (regions), and this part of the saline-alkali land can be preferentially developed and utilized under the premise of ecological control.
The key to saline-alkali land management is to reduce soil salinity, and the current treatment technology is mainly through irrigation and drainage, leaching, application of amendments and other engineering technical means to reduce soil salinity to the extent that crop production can be carried out. According to different types of saline-alkali land and water and soil conditions, the main technical models have been formed, such as the underground pipe salt drainage in the eastern coastal saline-alkali land, the comprehensive improvement of rice planting in the soda saline-alkali land in the northeast, and the improvement of drip irrigation under film in the arid oasis area in the west, and positive results have been achieved.
1.China's cultivated land resources are limited, and sustainable use and protection are facing pressure and challenges.
According to the "three adjustments" of national land, the current status of cultivated land in the country at the end of 2019 was 191.8 billion mu, compared with the "second adjustment" data at the end of 2009, a decrease of 1 in 10 years1.3 billion acres. From the perspective of cultivated land resource endowment, 64% of China's cultivated land is distributed in the north of the Qinling-Huaihe River, nearly half of the cultivated land is harvested once a year, more than half of the cultivated land is "harvested by the sky", and some are also facing the threat of desertification and rocky desertification. At the same time, after long-term development, the development and utilization intensity of China's limited cultivated land is too large, and the cultivated land capacity in some places is seriously overdrawn, soil erosion, groundwater is seriously overexploited, soil degradation and non-point source pollution are aggravated.
In addition, China's industrialization and urbanization still have a strong demand for land resources, and various non-agricultural constructions such as urban and rural construction and infrastructure support will inevitably still occupy a part of cultivated land, the scale of cultivated land loss caused by agricultural restructuring and afforestation and tree planting is still not small, the problem of illegal land use still occurs, and the contradictions and pressures between cultivated land occupation and protection are still prominent.
2.China's grain production and demand are generally tightly balanced, and the pressure to maintain a stable domestic supply has existed for a long time.
As of 2022, China's grain output has remained stable at 1 for 8 consecutive yearsMore than 3 trillion catties, the basic self-sufficiency of grain and the absolute safety of rations have been achieved. At the same time, we must also be soberly aware of the risks and challenges facing China's grain production. From the perspective of the demand situation, with the economic and social development, the people's living standards have improved, and the grain consumption structure has been continuously upgraded, coupled with the deepening of industrialization, the consumption of rice, corn and other crops in the industrial field has continued to increase, and the total grain consumption has increased rigidly, which has aggravated the tight balance of grain supply.
From the point of view of the production situation,The cost of agricultural production is rising, the carrying capacity of resources and environment is tightening, the agricultural infrastructure is relatively weak, and the ability to resist and reduce disasters needs to be improved.
From the perspective of the circulation situation,China's grain production continues to concentrate in core producing areas, cross-regional grain circulation increases, the challenge of coping with extreme weather and natural disasters and stabilizing grain production increases, and the risk of grain market fluctuations still exists.
From the external environment,China's staple crops are very dependent on foreign countries, but soybeans and other feed grains are highly dependent on foreign countries, and imports are relatively concentrated, global extreme weather, regional conflicts may disrupt the global food chain, coupled with the increasingly complex international environment, instability and uncertainty increase, which has a certain impact on China's food supply.
3.The comprehensive transformation and utilization of saline-alkali land is an important deployment to improve the national food security capacity.
As a non-traditional cultivated land resource that can be transformed and utilized, saline-alkali land is a "potential granary" for increasing grain production, and the reclamation of arable saline-alkali land resources can effectively supplement the cultivated land areaThe transformation and upgrading of existing saline-alkali cultivated land can effectively tap the yield potentialThe use of saline-alkali land to develop forage and modern animal husbandry according to local conditions can expand diversified food channelsControlling ecologically fragile saline-alkali areas can improve the ability of windbreak and sand fixation, prevent desertification of saline-alkali land, and improve agricultural production conditions and ecological environment.
The results of the "three adjustments" show that in the 10 years from 2009 to 2019, more than 12 million mu of saline-alkali land across the country has been transformed into cultivated land, especially the saline-alkali land in the Songnen Plain in the western part of Northeast China, the saline-alkali land in the coastal beach of North China, the saline-alkali land in the Yellow River Delta, and the saline-alkali land along the beach in Jiangsu have all been transformed and utilized to a certain extent, effectively improving the local agricultural production capacity. From a practical point of view, it is of great significance to carry out the comprehensive transformation and utilization of saline-alkali land to promote the quality, expansion and efficiency of agricultural production, promote the sustainable development of agriculture and ensure food security.
1.Strengthen top-level design and pay attention to planning and guidance.
Under the constraints of ecological security, water resource security, and food security, we should make full use of the results of the national survey of cultivated land reserve resources, combine the results of the third national soil census and the analysis and evaluation of water resources security, and comprehensively consider the saline-alkali types, salinity-alkali degrees and constraints in different regions, and carry out the analysis of the potential of comprehensive transformation and utilization of saline-alkali land, so as to form a comprehensive, accurate and detailed base map for the comprehensive transformation and utilization of saline-alkali land. On this basis, we should highlight the guidance of planning, study and compile a plan for the comprehensive transformation and utilization of saline-alkali land, clarify the comprehensive utilization goals of saline-alkali land by region, type and stage, adhere to steady and steady, continuous management, and overall advancement, and gradually form a spatial layout for the comprehensive utilization of saline-alkali land that is compatible with the natural geographical pattern and matches the agricultural production conditions.
2.Construct a scientific and reasonable governance model and technical path.
In accordance with the parallel idea of "soil improvement" and "crop salt tolerance", accelerate the implementation of key R&D projects related to the comprehensive transformation and utilization of saline-alkali land, enrich and expand the technical reserve for the development and utilization of saline-alkali land, build and promote the saline-alkali land treatment technology model applicable to different geographical regions, different soil types and different planting modes, accelerate the breeding and promotion of saline-alkali tolerant crop varieties, and realize the transformation of scientific research results into real productivity. Comprehensively adopt engineering, agronomic, chemical, biological and other measures to continuously improve the production capacity of salinized agricultural land of planted crops by improving soil properties and selecting and breeding saline-alkali tolerant crop varietiesFor saline-alkali land suitable for cultivated land, on the premise of fully assessing the ecological environmental impact and water resource guarantee capacity, orderly development and remediation of cultivated land, continue to do a good job in cultivation and utilization;For saline-alkali land that is not suitable for development as cultivated land, in accordance with the principle of suitability, it should be used for the development of animal husbandry and high-efficiency facility agriculture as a whole, and the comprehensive utilization of saline-alkali land should be strengthened from multiple angles.
3.Large-scale implementation of cultivated land reclamation in concentrated areas.
Combined with the national water network construction plan and the construction of major water conservancy projects, according to the results of the national survey and evaluation of cultivated land reserve resources and the analysis of water resources security, and comprehensively considering the influence of factors such as the spatial and temporal distribution pattern of water resources and the background of the ecological environment, the research and demonstration should be carried out in the areas where cultivated land reserve resources are concentrated, and the cultivated land reclamation project should be implemented in a concentrated manner to effectively supplement the cultivated land area. In accordance with the principle of first making it easier and then making it more difficult, and actively and prudently, we should promote the development of reserve resources of cultivated land such as saline-alkali land in different regions, and carry out centralized reclamation in areas with relatively good water resources conditions on a pilot basis.
4.Improve the incentive and restraint mechanism for the comprehensive transformation and utilization of saline-alkali land.
Explore the establishment of a "who invests, who benefits" comprehensive management of saline-alkali land benefit distribution mechanism, standardize and guide all kinds of subjects to participate in the comprehensive transformation and utilization of saline-alkali land, encourage local organizations to develop saline-alkali land and other cultivated land reserve resources to add new cultivated land, supplementary cultivated land index adjustment and other income is mainly used for cultivated land protection and quality construction, and give appropriate compensation to the main body of supplementary cultivated land. Explore the use of high-quality cultivated land cultivated by the state to support the implementation of major construction projects in ecologically fragile areas and undertaking key tasks of ecological protection. Adhere to the principle of "one acre of reclamation and one acre of stability", establish a long-term interest management and protection mechanism of "who uses, who manages and protects", and encourages rural collective economic organizations, enterprises and individuals who carry out the comprehensive transformation and utilization of saline-alkali land to continue planting and operation, so as to ensure that saline-alkali land can be used stably for a long time after development.
Let the "barren land" become the "granary of the country", explore the road of improvement and innovation of saline-alkali land, strengthen comprehensive development, restoration and utilization, and fully release the value of saline-alkali land as a "potential granary", which will surely achieve a win-win situation of ecological, economic and social benefits.