[Ecology topic]

　　In the second month of the lunar calendar, spring plowing is at that time.

Cultivated land is a precious natural resource and the lifeblood of food production.

　　Since the 18th National Congress of the Communist Party of China, my country has implemented the most stringent farmland protection system, firmly holding the red line of 1.8 billion mu of farmland, and providing a solid foundation for grain output to exceed 1.3 trillion catties for six consecutive years.

However, the latest survey shows that the high-yield arable land in my country only accounts for 31.24% of the total arable land, the middle and low grade accounts for more than 2/3, and the average grade of arable land quality is not high; the area of ​​obstacle degraded arable land accounts for as high as 40%, and the arable layer becomes shallower. Soil degradation problems such as soil compaction, acidification and salinization are still prominent.

　　These data remind us that arable land is not what we ask for, and that soil health needs to be cared for urgently under the premise of ensuring food security.

This year's government work report once again emphasized that "strictly observe the red line of 1.8 billion mu of arable land" and "strengthen the protection of arable land."

In the opinion of industry experts, the red line of cultivated land protection is not only quantitative, but also qualitative, and even more ecological.

In order to realize the “three-in-one” protection of quantity, quality, and ecology of cultivated land, there are still scientific and technological support and legal guarantees that need to be solved urgently.

　Black soil becomes thinner, harder, and thinner. 14.5% of arable land is severely acidified

　　Speaking of farmland degradation, Zhang Bin, a researcher at the Institute of Agricultural Resources and Regional Planning of the Chinese Academy of Agricultural Sciences, first mentioned the black land in Northeast China: “Long-term intensive management and mechanized farming have made the organic matter structure of the black land worse, and the microorganisms can’t do well. Live', the soil is compacted, and when it rains, water accumulates in the fields to form a flood, and the soil erosion is also very serious...The black soil is thinned, hardened, and thinner."

　　The red and yellow soil in the south is also worrying.

The latest data from the Ministry of Agriculture and Rural Affairs shows that due to the massive loss of alkaline base ions such as potassium, calcium and magnesium, coupled with factors such as extensive agricultural operations and low fertilizer utilization, 14.5% of my country's arable land has been severely acidified.

In the past 30 years, the area of ​​acidified cultivated land with a soil pH of less than 5.5 in Hunan, Jiangxi, and Guangxi has increased by 35%, and crop yields have decreased by more than 20%.

At the same time, due to the increase in soil salinity under drought conditions, my country’s saline-alkali arable land has reached 114 million mu, an increase of nearly 30% compared to the 1980s. It is mainly distributed in northern, northeast, northwest inland and coastal areas, and in some places even So abandon farming and wasteland.

　　According to the National Cultivated Land Quality Grade Bulletin of the Ministry of Agriculture and Rural Affairs in 2019, the quality of cultivated land in my country is divided into ten grades from high to low, with an average grade of 4.76.

The first to third grade arable land is high-yield land, accounting for only 31.24% of the total arable land; the fourth to sixth grade is middle-yield land, accounting for 46.81% of the total arable land, which will be key areas and important breakthroughs for increasing grain production in the future; Low-yield fields accounted for 21.95%. The basic soil fertility of this part of the cultivated land is relatively poor, which is a bottleneck and difficulty in improving the inherent quality of cultivated land.

　　"Our country uses 9% of the world's arable land to feed nearly 20% of the world's population, relying on the production potential released by the land." Zhou Wei, deputy director of the Institute of Agricultural Resources and Agricultural Regional Planning of the Chinese Academy of Agricultural Sciences, told reporters that their research The team has made such a calculation: if China's arable land fertility is increased by one level, 120 billion kilograms of grain can be added; if the fertilizer utilization rate is increased by 10%, it can reduce the nitrogen and phosphorus emissions of farmland by 50%, effectively reducing agriculture Non-point source pollution.

"Therefore, the protection and utilization of cultivated land and the improvement of soil fertility need urgent promotion." Zhou Wei emphasized.

　　Yun Wenju, a researcher at the Center for Land Remediation of the Ministry of Natural Resources, believes that cultivated land resources not only have value due to human use, as natural resources, the relationship between humans and cultivated land should be a community of life.

“Therefore, the health and sustainable development of cultivated land is not only the key to food security, but also related to ecological civilization. Faced with problems such as low background quality and degradation, cultivated land should be fulfilled the responsibility of protecting the trinity of quantity, quality and ecology. "

　Insufficient technological support, standards, lack of technology, there is a "black box"

　　In recent years, my country’s main focus for improving the quality of arable land is to increase investment and implement high-standard farmland construction. In 2021, my country plans to build 100 million mu of high-standard farmland.

However, in the process of implementing protection and improving the quality of cultivated land, the fundamental problem of insufficient scientific and technological support has become increasingly prominent.

　　The lack of relevant standards for farmland protection is a typical example.

To protect the quality of cultivated land, the establishment of scientific monitoring and evaluation standards is the basis and prerequisite.

However, it was not until the end of 2016 that my country officially implemented the first national standard for cultivated land quality.

Management standards for farmland quality monitoring, investigation, evaluation, and protection are still lacking.

　　Yun Wenju pointed out that in terms of cultivated land quality and ecological protection, our technology is still in a "black box" state. Many background problems of cultivated land have not been clarified, and it is impossible to "prescribe the right medicine" to develop hard technologies and hard methods.

"Only by investigating and studying the data, layout, quality and ecological conditions of cultivated land across the country, can the most stringent cultivated land protection system'grow teeth'."

　　Zhou Wei said frankly that my country has always lacked top-level design in terms of cultivated land research.

Cultivated land-related disciplines involve soil physics, soil chemistry, soil microbes, soil omics, etc.; in terms of monitoring methods, they also involve emerging technologies such as remote sensing satellites, unmanned aerial vehicles, sensors, etc., and the integration of multiple disciplines is strong.

"However, for a long time, my country's farmland protection research has lacked systematic and strategic nature, has not undertaken enough national missions, and has clearly insufficient research on integration."

　　In response to the degradation of cultivated land, my country lacks synergistic high-yield and cultivated land protection technology, and also lacks protective technology and machinery for serious soil erosion in farmland and gradual thinning of cultivated soil.

In addition, compared with seed technology, my country's arable land subject is relatively backward.

"Especially in recent years, the frontiers of disciplines represented by soil omics have emerged, and there is an urgent need to improve scientific research conditions to obtain original and breakthrough results, and to further enhance the international discourse power." Zhou Wei pointed out.

　　Professor Li Baoguo of China Agricultural University also believes that in the past decade or so, my country has still had obvious shortcomings in the automation, precision, and all-round control of cultivated land protection and utilization. It is difficult for R&D technologies such as protective tillage and cultivated land quality improvement to give full play to their applications. has an effect.

The concept of "only need not support" needs to be reversed, protection still needs legislation

　　In the first two years, Zhang Bin collected soil samples in the mountainous areas of Yunnan and explained to the local people the knowledge of protecting farmland and preventing soil erosion.

The villagers told him: "Teacher Zhang, we have a string in our hearts to protect the soil and cultivated land." This incident moved Zhang Bin deeply, and it also made him reflect: As the process of urbanization accelerates, he is far away from farming life. In people's minds, is this string weakening?

　　"Everyone should understand the basic knowledge of protecting cultivated land, and have this string in their hearts." Zhang Bin believes that the non-agriculturalization of cultivated land and the over-utilization of cultivated land that have occurred in recent years are precisely due to the fact that "only need not support", Caused by misconceptions such as pure pursuit of economic development.

In his view, protecting cultivated land is the common responsibility of the whole society, and the concept of protection should be deeply rooted in the hearts of the people.

　　"The characteristic of arable land is the essential attribute of its inherent value. However, for a long time, we have neglected the health and sustainable development of arable land, and have not established and perfected the relevant restraint and incentive mechanism and accountability system, so that the health of arable land has been protected. It is difficult to implement it." Yun Wenju pointed out.

　　"It is necessary to speed up legislative protection." Zhang Bin said that in terms of land management, my country has issued a land management law; in terms of protecting farmland, my country has issued a soil pollution prevention and control law.

However, compared with the special soil protection laws generally established in Europe and the United States, my country still has a blank in the special legislation for the protection of cultivated land, and only has basic farmland protection regulations.

"From the perspective of legal system construction, we must protect both the quantity and quality of cultivated land, and let the concept of protecting and cherishing cultivated land take root in the hearts of the people, and we are still far from doing enough."

　　Yun Wenju suggested that we should learn from relevant foreign legislative experience, modify and improve the relevant provisions of my country's cultivated land protection, and increase the content of cultivated land quality, pollution and degradation, so as to provide a direct legal basis for cultivated land health protection.

At the same time, establish a sound farmland health protection performance evaluation system and accountability system, and link up and down to implement the responsibility of farmland health protection level by level.

　Regular "physical examination" Deploy an innovative platform to maintain effective monitoring

　　"Science and technology innovation is the key to sustainable agricultural development, and caring for the health of cultivated land is a strategic technological innovation project related to the survival and development of the Chinese nation." Yun Wenju pointed out that the current quality classification of cultivated land resources has been included in the ongoing third national land survey. This will lay the foundation for understanding the natural background of cultivated land resources and the ecological environment, and will also effectively promote the development of scientific and technological innovation in cultivated land protection.

　　He suggested that a nationwide farmland health monitoring network and early warning mechanism should be established by relying on scientific and technological means, to maintain effective monitoring of farmland quality and health dynamics throughout the year, to conduct regular "physical examinations" for farmland, and to carry out a top-down farmland health year. The monitoring results are updated and evaluated to achieve "early prevention and early treatment".

　　Li Baoguo pointed out that there is an urgent need to deploy a scientific and technological innovation platform in the national cultivated land resource concentration area, increase funding, and provide an overall solution for the protection and utilization of cultivated land resources.

　　Zhou Wei believes that to realize the “three-in-one” protection of the quantity, quality, and ecology of cultivated land, the integration of multiple disciplines such as soil science, fertilizer science, microbiology, economics, agricultural information, and smart agriculture is needed.

In addition, changes in the amount of cultivated land must be monitored through remote sensing technology based on high-resolution satellites, and changes in quality require comprehensive research in disciplines such as soil science, microbiology, molecular ecology, and big data. "These also require major scientific research platforms and Infrastructure to carry it".

It is reported that the Chinese Academy of Agricultural Sciences will build a "National Cultivated Land Scientific Research Center" for this purpose, relying on the past scientific research foundations of cultivated land protection and utilization, and explore ways to strengthen soil omics, soil improvement, cultivated land conservation, smart cultivated land, cultivated land management strategies, and international cooperation. Comprehensive and overall innovation research.

"This is also the need to strengthen the country's strategic scientific and technological capabilities." Zhou Wei emphasized.

　　In Yun Wenju's view, my country's special national conditions for the use of cultivated land are unique in the world, so the wisdom of Chinese scientists must be used to solve China's problems.

"For cultivated land, we should not only take over it completely from the hands of the ancestors, but also work hard to give it to future generations in a more perfect condition."

　　(Reporter Yang Shu)