Author: Li Yuyi (Chief Scientist and Researcher of the Innovation Team of Saline-alkali Soils Amelioration at the Institute of Agricultural Resources and Regional Planning (IARRP) of the Chinese Academy of Agricultural Sciences (CAAS) )

Saline-alkali land is an important reserve strategic arable land resource in China, with a large area, wide distribution, various types, and a long history of governance, which has played an extremely important role in guaranteeing national food security and expanding arable land resources.  In the new era, promoting the comprehensive utilization of saline-alkali land, thoroughly exploring the agricultural production potential of saline-alkali land, is of great responsibility and significance.

From the macro data perspective, there is huge potential for the comprehensive utilization of saline-alkali land. The second national soil survey data in China shows that there are about 37 million ha of usable saline-alkali soil resources across the country. In 2011, the Ministry of Agriculture organized a survey of 18 provinces (autonomous regions and municipalities) with large areas of saline-alkali land, and found that the total area of usable saline-alkali land was about 20 million ha, with saline-alkali farmland accounting for 38% and saline-alkali wasteland (grassland) accounting for 62%.

From historical experience, the comprehensive development of saline-alkali land has made outstanding contributions to the increase of grain production in China. "The Scientific and Technological Battle for the Comprehensive Treatment of Drought, Waterlogging, and Saline-alkali in the Huang-Huai-Hai Plain" is the most typical case. The area of saline-alkali arable land in the Huang-Huai-Hai Plain has decreased from 3.3 million ha in the 1980s to sporadic distribution at present. In addition, the successful case of converting dryland into paddy fields by treating alkali with water is a successful example of improving the utilization of soda saline-alkali soil in the Northeast region. The area of paddy fields developed from saline-alkali land in the western part of Jilin province alone has exceeded 333 thousand ha, and the improvement effect and economic benefits are extremely significant.

From the current situation, the comprehensive utilization of saline-alkali land is facing complex challenges. First, there is a lack of top-level design for the new requirements of "orderly development and classified transformation" in the governance of saline-alkali land. Currently, the types, distribution, quantity, degree of salinization, and related water resources and water conservancy projects of saline-alkali land in the country are not clear, and there is an urgent need to systematically plan the layout and scale of the development and utilization of saline-alkali land. Second, there is a lack of ecological governance technologies for saline-alkali land that meets the new demands of ecological protection and high-quality development in the new era. There is an urgent need for mature technologies, products, equipment, and integrated models that are low-cost, high-efficiency, green, and low-carbon. It is necessary to strengthen the research and development of new technologies such as modern engineering technology, brackish water irrigation technology, salt-tolerant crop breeding, and microbial revitalization. Third, the concept of relying mainly on "improvement" is deeply rooted, and there is a need to adhere to the new concept of " adapt the seed to the land", achieving a simultaneous and synergistic approach to "adapt the seed to the land" and "improve the soil to let the seed grow", and promoting diversified development and utilization according to local conditions. Fourth, there is a lack of sound long-term mechanism for promoting the comprehensive utilization of saline-alkali land. The governance of saline-alkali land has a long cycle, high investment, and high maintenance costs, and it is reversible. Currently, there are issues such as inadequate investment in saline-alkali land governance funds, incomplete investment and financing mechanisms, lack of post-maintenance funds, and unclear ownership rights after governance, which need to be urgently addressed.

Improving the quality of saline-alkali land is the main focus of integrated utilization in recent years. Due to the constraints of water resources and ecological conservation requirements, the cost and ecological risks of developing saline-alkali wasteland are high, and the development potential is limited. Saline-alkali arable land is one of the main types of low and medium yield fields in China at present, and it has relatively better conditions. After effective treatment, large areas of lightly to moderately saline-alkali arable land have significant potential for increased yields. Under the condition of water resource guarantee, the yield can be increased by more than 100 kg/667m2. The annual increase in yield on 6.67 million ha of saline-alkali arable land can reach 10 billion kg, equivalent to the addition of 1.67 million ha of arable land (calculated based on an average yield of 200 kg/667m2), which is of great significance for enhancing food security. In the near future, the focus should be on the treatment of saline-alkali arable land, and technical improvement plans for treating over 6.67 million ha of existing saline-alkali arable land should be formulated and implemented as soon as possible. Multiple channels of funding can be coordinated for the treatment by combining with projects such as the construction of high-standard farmland, in order to improve the quality and productivity of farmland.

In terms of utilization direction, China adheres to the principles of water-based planning, seed-based adaptation, classified measures, and innovation-driven advancement in the comprehensive utilization of saline-alkali land. Specifically, for lightly saline-alkali land, the nation focuses on the production of food crops, integrate and apply technologies such as salt-tolerant and high-yielding varieties, fertilizer reduction and efficiency enhancement, and water-saving irrigation, striving for "high crop yields".

For moderately saline-alkali land, the nation focuses on the integrated production of oil and forage crops. We integrate and apply technologies such as high-quality salt-tolerant varieties, salt control, organic fertilization, crop rotation, and  planting-breeding combination, striving for "good production".

For heavily saline-alkali land, the nation focuses on the production of characteristic plants such as oil sunflower and wild soybean. We strengthen the integrated application of technologies such as water-saving irrigation and drainage, stress-resistant cultivation, and high-value utilization, striving for "distinctive features".

The comprehensive utilization of saline-alkali land in China needs to be promoted in a multidimensional way. At the top-level planning level, it involves regional resources, technical equipment, investment and other issues. It is necessary to adhere to the system concept of "mountain-river-forest-farmland-lake-grassland" life community" and to reasonably arrange the goals, tasks, and technical paths of the comprehensive utilization of saline-alkali land. The key tasks of comprehensive utilization of saline-alkali land should be promoted in stages and in different regions. The country should focus on the goal orientation, demand orientation, and effect orientation of the comprehensive utilization of saline-alkali land. The direction of improvement and utilization of light, medium, heavy and abandoned saline-alkali land should be clearly defined. The governance techniques and planting models suitable for the characteristics of saline-alkali land should be improved and localities should be guided to carry out the improvement and utilization of saline-alkali land according to local conditions.

At the level of technological innovation, China should focus on the goals of being green, efficient, and low-cost. The key breakthroughs should be made in the breeding of salt-tolerant crops, green cultivation with salt resistance, biological and ecological enhancement, intelligent and precise control of water and salt, carbon sequestration and storage in saline-alkali land, and other new technologies and products. The country should also increase research and development efforts on modern engineering technologies and key equipment for efficient desalination under water-saving conditions. In terms of salt-tolerant crop varieties, China should build a technical system for the adaptive improvement of saline-alkali land, with soil green conditioning, soil fertility cultivation, and efficient water-saving as the core. The focus should be on targeted and practical technological research and development.

To expand the industry of saline-alkaline land management, it is necessary to deepen the use of various forage plants and functional plants produced on saline-alkaline land, and adopt the principle of "Big Food View" to develop and utilize crops and aquaculture in different types and degrees of saline-alkaline areas. The restrictions on the use of saline-alkaline land should be relaxed. A collaborative innovation research and development platform integrating government, industry, academia, research, and application should be established to promote the integration of scientific and technological innovation throughout the entire chain of saline-alkaline land development. A new agricultural technology innovation and service system should be created to build specialty brands and promote the development and value enhancement of characteristic industries and resources on saline-alkaline land.

In terms of institutional innovation, China should explore the establishment of a supporting system for the comprehensive utilization of saline-alkali land, integrating government, enterprises, academia, and research, to promote the fusion of resources, enhance technical standards for governance, and improve intelligent process supervision and post-management. China should incorporate the utilization of saline-alkali land into the assessment of land protection and food security responsibilities, and ensure that local governments assume investment responsibilities. The nation should encourage the participation of social capital and financial support, create a "research and development + promotion + industry + commercial" full chain, promote integrated investment and financing, development, management, and operation, and promote the integrated development of the primary, secondary, and tertiary industries.

(Source: Guangming Daily /Translated and edited by IARRP)