It's harvest time again. In the endless fields, huge corn cobs were hung on the tall straw. Under the brilliant sun, the waist was straight. Pointing to a thick layer of blackened and rotten straw in the field, Wang guiman, head of Lishu County Agricultural Technology Extension Station in Jilin Province, said: "we have 'quilt' the black land, and the black land is more 'fat'." In July 2020, when general secretary Xi Jinping visited Jilin, he stressed that effective measures should be taken to effectively protect and utilize black land as a "giant panda in cultivated land". Over the past year, the pear tree model has been continuously upgraded to adapt to the development of modern agriculture on the basis of ensuring grain production. Hard exploration and wading out of the road of protection Northeast China is one of the four black soil areas in the world. Its unique characteristics make it an excellent area to nourish food growth and a "ballast" to firmly stabilize food security. "I'm terribly distressed!" said Wang guiman, who has dealt with the black land for decades. In previous years, the grain output in Northeast China was increasing, but the excessive reclamation and the extensive use of chemical fertilizer made the black land thinner and thinner. Concerns intensified around 2000. The rare strong wind swept away the black soil layer by layer. Since then, how to keep the black soil on the basis of stable production has become a top priority in his heart. At that time, European and American countries had explored conservation tillage methods based on straw returning to the field and less no tillage and sowing. According to local conditions, some researchers developed experimental fields in pear trees and began to explore conservation tillage one after another. One of them is Li Baoguo, a professor at China Agricultural University. After Li Baoguo visited Lishu County in 2008, he and his colleagues established a test field in quanyangou village the following year. In 2011, he became the head of Jilin pear experimental station of China Agricultural University and worked with experts from scientific research institutions such as the Chinese Academy of Sciences to study local conservation tillage technology. From soil testing, to measuring the amount of straw returned to the field, to studying different sowing methods... Every year, Li Baoguo comes to pear tree almost every month. He also sets up a graduate internship base here to write his papers on the earth. At first, there were many difficulties in work. Leaving straw in the field has changed the farming method inherited for thousands of years. Local farmers firmly opposed: "what? No! I've planted land for decades and haven't seen anything like this." Wang guiman did it. He first found Yang Qingkui, a big local grain grower, patted his chest and drew him a "big cake": "do as I say, I'll guarantee you to collect 2000 kg more per ridge." Yang Qingkui agreed with his teeth. "That's true!" after ten years, Yang Qingkui told reporters that by "covering the black land with quilts", one hectare of the experimental plot saved more than 2000 yuan and increased production by more than 2000 kg per year; After five years of straw mulching and no tillage, the surface soil organic matter increases by about 20%, and more than 800 tons of soil wind erosion can be reduced per hectare every year... This is the conservation tillage system pear tree model explored by agricultural experts in many scientific research institutes such as Li Baoguo after unremitting efforts for more than a decade. "Black land protection alliance" escorts the black soil granary At the most difficult time, the general secretary's speech gave them guidance to move forward. In December 23, 2013, general secretary Xi Jinping pointed out at the central rural work conference that the fundamental guarantee for national food security is arable land, and farmland is the lifeblood of grain production. The intensive introduction of policies and measures makes the promotion work coincide with timely rain. From 2015 to 2020, the central government will allocate special funds to carry out the pilot of black land protection and utilization in the four provinces (regions) of Northeast China, gradually increase financial support and expand the scope of project implementation. In 2021, the No. 1 central document was promulgated to upgrade the protection of black land to national projects. The Ministry of agriculture and rural areas and other seven departments jointly issued the implementation plan of the national black land protection project (2021-2025), which defined the tasks and objectives of China's black land protection and utilization during the 14th Five Year Plan period. Meanwhile, Heilongjiang and Jilin have issued relevant implementation opinions on black land protection. In order to further expand the participation in black land protection research, the local government holds the "black land forum" every year. Li Baoguo and his colleagues will invite many soil science experts at home and abroad to come to pear tree and gather together with agricultural cadres, large grain growers and agricultural machinery manufacturers to make suggestions. Today, the "black land forum" has been held for seven consecutive sessions, and its influence is increasing day by day. They also formed the "black land protection alliance". One of the special activities of the alliance is the "challenge meeting". Experts and farmers sit together and analyze problems face to face - experts say straw should be returned to the field, but the ground temperature is not enough after planting and covering, and seedlings do not appear in spring. What should we do? What is the problem of stop and go when the no tillage planter is used In the "provocations" and debates again and again, experts continue to improve machinery and technology, and farmers' operation is becoming more and more standardized. Wechat group is the daily communication platform of the alliance. There are heated discussions in the group of hundreds of people every day. The upgraded version of pear tree model accurately connects agricultural modernization Zhang Wendy, a big grain grower in Lishu County, is busy harvesting corn in the field these days. He broke off a ear of corn from the straw. "This ear of corn must weigh seven or eight Liang. It's not a problem to harvest 25000 Jin a long. It's another bumper harvest!" he said happily. Over the past year, the pear tree model has been upgraded. According to relevant planning, conservation tillage will cover 70% of suitable cultivated land in Northeast China in the future. In order to solve the problems of "competing for straw", "relying on subsidies" and "catching up with tasks" in the promotion, the alliance is further exploring in the direction of building a modern agricultural system. Since 2021, the pear tree model test team has tried to establish a modern agricultural production unit and create an upgraded version, that is, taking 300 hectares of concentrated contiguous land as a unit, introducing financial, insurance, grain storage, agricultural materials and other service links on the basis of the promotion of conservation tillage technology, so as to transition from protecting black land to building a modern agricultural system, Finally, a modern agricultural technology extension model will be formed. In March this year, Wang guiman convened the local major grain growers and the heads of banks, insurance, grain collection and storage enterprises to actively connect the supply and demand sides, discuss the atmosphere warmly, and finally form a perfect scheme: the Agricultural Bank of China launched the pear tree model "Black soil granary loan", COFCO Trading Co., Ltd. Cai jiaku provides professional storage, and Jilin Bada pesticide Co., Ltd. establishes a special company to provide pesticide support. "If the experiment is successful, it will greatly improve the comprehensive benefits of agricultural production and realize the connection between black land protection and modern agricultural production system." Li Baoguo said, "our goal is not only to consolidate the foundation of food security and secure China's rice bowl, but also to make the bowl filled with grain and refined grain!" (outlook new era)