Awaken the "sleeping" arable land reserve resources

Saline land, synonymous with barrenness, "ten years and nine harvests" is its former label.

Saline-alkali land, a potential "new granary", is widely distributed and large in area.

As the world's third largest distribution of saline-alkali land, China has 15.5 billion mu of saline-alkali land, equivalent to nearly eighty percent of the existing arable land. In recent years, all regions and departments have strengthened governance and transformation, promoted the reduction of the total area of saline-alkali land, and the proportion of severe saline-alkali land area has been continuously reduced, and positive progress has been made in comprehensive utilization. On May 17, the Ministry of Agriculture and Rural Affairs made a new deployment, making it clear that it is necessary to systematically plan and promote the comprehensive utilization of saline-alkali land as a whole.

What are the challenges of waking up this "sleeping" arable land reserve resource? What are the prospects for the future? Our reporter conducted an interview on this.

Great potential for development and utilization

-- The use of 1% more saline-alkali land in the world is equivalent to an increase in world grain production of 5000 million tons, which can meet the annual food needs of 1 million people

In Wuzhuang Village, Kenli Subdistrict, Dongying, Shandong, grain farmer Hu Changhai is busy harvesting wheat. Talking about the land in front of him, Hu Changhai sighed: "In the past, we were bare, full of white hair alkali, and they couldn't grow anything, it was really 'ten years and nine years without harvest, bran vegetables for half a year'." ”

"Dongying is located on the shore of the Yellow River and the Bohai Sea, as a place of retreat, the soil is seriously salinized, and the city has about 341.38 million mu of saline-alkali land, accounting for 2.196% of the saline-alkali land area in Shandong Province, which is a delta-type saline-alkali land with relatively large scale and difficulty of utilization." According to the relevant person in charge of Dongying Municipal Bureau of Agriculture and Rural Affairs, from the perspective of grain production, Dongying saline-alkali arable land covers an area of 60.<> million mu, accounting for about <>% of the city's arable land.

Dongying is a microcosm, and "difficulty in growing grain on saline-alkali land" is a worldwide problem. According to statistics, saline-alkali land covers more than 80 countries and regions on six continents, covering an area of more than 8 million hectares. In these places, the soil salt and alkali content is significantly higher than normal, and it is difficult for crops to grow, among which when the soil salt content exceeds 3‰, the crop emergence rate will be less than 6%, the yield will be reduced by 50%, and there will be almost no harvest.

"China has 15.15 billion mu of saline-alkali land, with various types, in addition to coastal areas such as Shandong, there are also a large number of saline-alkali lands in the Songnen Plain in Northeast China, the Hetao region of Inner Mongolia and Xinjiang." Liu Zhixin, a researcher at the Saline-alkali Land Comprehensive Utilization Service Center of the Yellow River Delta Agricultural High-tech Industry Demonstration Zone in Shandong Province, said that about 5 million mu of the <>.<> billion mu have development and utilization potential, and such a large area of land resources, if fully utilized, will effectively increase cultivated land and ensure food security.

According to the relevant person in charge of the Ministry of Agriculture and Rural Affairs, according to China's practice, the average yield per hectare can reach 6 tons per hectare when rice is grown in improved saline-alkali land. If the global saline-alkali land can be used by 1% more, it is equivalent to an increase in world grain production of 5000 million tons, which can meet the annual food needs of 400 million people based on 1 kg per capita.

Hu Changhai has a real feeling about such potential: "After more than 10 years of hard work, the once saline-alkali flats are becoming 'rice grain rivers'. Last year, the average yield of wheat per mu exceeded 460 kg, setting a typical high yield of wheat in saline-alkali land. According to the current situation, this year's harvest is not similar, and I hope to harvest more in the future. ”

Increase the intensity of transformation and improvement

-- Grasp the law of water and salt movement, coordinate the relationship between water and salt, and cultivate soil fertilization

How to further develop the potential and get more food on saline-alkali land? Increasing the intensity of transformation and upgrading is an important part.

Experts said that the treatment of saline-alkali land is difficult, and the important reason is like farmers often say that "alkali is born, salt is long, can not be completely removed", should fully grasp the law of water and salt movement, coordinate the relationship between water and salt.

"The previous governance model was a simple 'irrigation and salt washing', although the effect was quite obvious, but 1 mu of land had to use 180 to 200 cubic meters of water, and a lot of fresh water resources were wasted. And as the water evaporates, the deep salinity also produces secondary salinization through transpiration. Liu Zhixin said, "Through active exploration, we began to adopt new models such as pipeline water saving and salt reduction, brackish water utilization, etc., replacing the past channels with pipelines, and replacing the deep ditches that were 10 meters wide in the past with small ditches, which can stably control salt from 3‰ to 4‰ below 6‰ in three years, saving more than 3% of fresh water." ”

According to reports, Shandong has nearly 900 million mu of saline-alkali land, and according to the current situation and characteristics of saline-alkali land, saline-alkali land improvement is carried out by digging ditches to drain salt and planting rice to salt. Through improvement, the province's saline-alkali arable land can grow 360.100 million mu of grain, 100 million mu of cotton, 10 million mu of jujube trees and <>,<> mu of pasture.

In Xinjiang, "salt-eating plants" are becoming a "sharp weapon" for the transformation and upgrading of saline-alkali land. Tian Changyan, a researcher at the Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, said that Xinjiang is the largest distribution area of salinized soil in China, and salinization has a great impact on its agriculture. "In the investigation and production, we found that although some salinized lands cannot grow common sweet soil plants or crops, there are many 'salt-eating plants', which can 'eat' and remove salt from the soil. We selected some trial seeds with feed value and economic value, and the soil salinity was reduced by 40% in the first year, by more than 60% in the second year, and by 85% to 90% in the third year, making saline-alkali land a land that can be planted normally. Tian Changyan said.

In addition to salt control, it is also necessary to cultivate the soil. As one of the three major concentrated distribution areas of soda saline-alkali land in the world, the western region of Jilin Province has introduced a number of scientific research institutes and enterprises in recent years, using a variety of soil amendments such as silicone, phosphogypsum, polymer slow-release fertilizer, desulfurization gypsum, etc., and achieved good results.

"I have been working with saline-alkali land for seven years, and in the first year, I planted rice in saline-alkali land, and due to the lack of scientific and technological methods, I only harvested more than 7 kilograms per mu. In 200, under the guidance of experts, the soil was improved, and the mu yield reached more than 2017 kg, and last year it reached more than 430 kg. Guo Xiaohong, a farmer in Xinping'an Town, Da'an City, located in northwest Jilin, said.

Not only "renovating the soil", but also breeding "new seeds"

——The cultivation and promotion of high-quality saline-tolerant crop varieties will effectively increase the production capacity of saline-alkali land

It is not enough to "change the soil". The key is to change the concept of breeding, from the treatment of saline-alkali land to adapt crops to the selection of saline-tolerant plants to adapt to saline-alkali land.

"The cultivation and promotion of high-quality saline-tolerant crop varieties will effectively increase the production capacity of saline-alkali land, which is of great significance to ensuring food security." Xie Qi, a researcher at the Institute of Genetics and Development of the Chinese Academy of Sciences, and his team recently discovered the main alkali tolerance gene AT1 of crops for the first time and revealed its mechanism of action, "On the basis of theoretical breakthroughs, we used AT1 genes to improve salinity-tolerant breeding of related crops and carried out field experiments." Among them, in the Pingluo saline-alkali land of Ningxia, the yield of sorghum grain increased by 20.1%, and the yield of millet increased by 19.5%; In the Da'an saline-alkali land of Jilin, rice yield increased by 22.4% to 27.8%. ”

With the change of concept, all regions and departments have accelerated their actions, and more and more new varieties of saline-tolerant plants have been born on saline-alkali land. In Nanpi, Hebei, the "Xiaoyan 60" variety can produce about 1 kg of wheat per mu; In Dongying, the mu yield of "Yanhuang Xiangjing" is 550.505 kg, and the appearance quality and processing quality have reached the first-class standard of high-quality rice; in Ningxia, researchers have selected and bred a number of new varieties of salinity-tolerant such as goji berries, corn, rice, and grapes on the saline-alkali land of the Hetao Plain, and the yield has been greatly increased.

Recently, the National Technology Innovation Center for Comprehensive Utilization of Saline-Alkali Land was officially inaugurated. The innovation center is jointly built by the Chinese Academy of Agricultural Sciences and other units and 18 saline-alkali land scientific research institutions and enterprises in the United Nations, focusing on the three key areas of saline-alkali land biological breeding, saline-alkali land production capacity improvement and saline-alkali land ecological utilization, and plans to cultivate more than 3 new varieties (lines) of grain and oil, forage and special cash crops that are moderately salinity-tolerant in about 80 years, and the promotion area of new varieties of salinity-tolerant crops will reach 3000 million mu, driving the quality of 1300 million mu of saline-alkali arable land to generally improve by 1-2 grades. The comprehensive production capacity per unit area increased by more than 25%.

"The establishment of the National Saline-alkali Land Comprehensive Utilization Technology Innovation Center is to change from changing land to changing land to suitable land through the deep integration of production, education and research. It is expected that after a period of development, more than 1 million mu of saline-alkali land can be used to supply more grain, oil and food. Mei Xurong, vice president of the Chinese Academy of Agricultural Sciences, said.

The Ministry of Agriculture and Rural Affairs said that in the future, it will give play to the key role of agricultural scientific and technological innovation, carry out transformation and upgrading by sub-region and type according to the results of the saline-alkali land census, strengthen the development and promotion of crop varieties suitable for saline-alkali land, promote the research and development of agricultural machinery agronomic supporting and processing technology and equipment, and promote this strategic problem with comprehensive measures.

(People's Daily Overseas Edition, Qiu Haifeng)