Our scientists compete for soil diseases to keep 45 million mu of greenhouse crops full of vitality.

"in the past, when the land suffered from diseases, the harvest was no more than 8000 jin per mu, and fallow with stubble did not work, but now using soil steaming and fumigation technology, the annual yield per mu can reach about 13000 jin." Wang Wengang, a farmer in Shidui Town, Anqiu, Shandong Province, who has grown ginger for ten years, told reporters.

The story of Lao Wang's income increase is inseparable from the current application of soil-borne disease control technology in our country. In the face of increasingly serious soil-borne diseases Chinese scientists are stepping up scientific research and promotion efforts to declare war on soil diseases and have achieved remarkable results.

(subhead) soil can also get sick and soil-borne diseases become invisible killers of greenhouse crops.

People get sick, and so does the soil.

About soil disease, there is a scientific term related to it, called soil-borne disease. It refers to the soil diseases caused by pathogens living in the soil from the roots or stems of crops when the conditions are suitable, which often occur in the greenhouse and often bring about root rot and wilt of crops, which is a kind of soil disease in the eyes of fellow villagers. Continuous cropping of crops, improper fertilization and soil nematodes are the three main causes of soil-borne diseases.

"soil-borne diseases are easy to occur when a single crop is cultivated continuously in a field for a long time. With the rapid development of facility agriculture in China in the past 10 years, soil-borne diseases show a high incidence. This kind of disease is invisible and untouchable, and it is the invisible killer that gives greenhouse farmers the biggest headache. " Cao ao Cheng, chief scientist of the soil fumigation technology project and researcher of the Institute of Plant Protection of the Chinese Academy of Agricultural Sciences, told reporters.

In recent years, with the intensive cultivation of high value-added crops such as greenhouse vegetables in China, soil-borne diseases are becoming more and more prominent, especially in greenhouse, greenhouse crops and other facility agriculture. Statistics show that usually after three to five years of planting, soil-borne diseases begin to appear, and the yield and quality of crops will be seriously affected, resulting in a yield reduction of 20% to 40%, and sometimes even the consequences of no harvest.

(subhead) scientists form a group to compete for soil disease "specialty" chloropicrin to take orders in the face of crisis.

The reporter learned that after the emergence of soil-borne diseases, fellow villagers often use the method of crop rotation or soil exchange to prevent and cure them. However, the result of crop rotation will lead to a sharp decline in farmers' income, while the method of changing soil is laborious and laborious, which is almost impossible when the rural labor force is becoming more and more expensive.

"in areas where soil-borne diseases are serious, rotation is mostly adopted, but the rotation of high value-added crops and low-value crops not only has low economic benefits, but also destroys some traditional superior industries." Cao Aocheng said.

In an urgent situation, some fellow villagers turned to the doctor at random when they were ill. In the past, some farmers used "black drugs (pesticides banned by the state)" to control devastating soil-borne diseases, resulting in the well-known "poisonous ginger" incident, which had a serious impact on the ecological environment and consumer health.

There is also a control method of soilless cultivation, which is relatively high-end, but it is not in line with the current situation of agricultural production in our country.

How to effectively solve the increasingly serious soil-borne diseases in crop production and promote the sustainable development of agriculture has become a key issue in agricultural production. In view of the growing soil-borne diseases in China, the Institute of Plant Protection of the Chinese Academy of Agricultural Sciences cooperates with a number of relevant units to declare war on soil-borne diseases, develop and promote soil fumigation, which is suitable for the prevention and control of soil-borne diseases in China.

"because the fumigants used in the key technologies have low molecular weight, rapid degradation and no groundwater pollution and pesticide residues, they are conducive to environmental protection and food safety, and significantly improve the competitiveness of China's vegetables and high value-added crops in the international market." Cao Aocheng said.

The reporter learned that the key technology mentioned by Cao Aocheng is mainly chloropicrin, which is praised by the industry as a "specialty" of soil-borne prevention and control: it can not only kill bacteria, but also have the function of weeding, but also stimulate soil vitality and reduce the application of chemical fertilizers and pesticides.

According to the statistics of Anqiu Plant Protection Station, in the areas where this technology is applied, the amount of pesticides and chemical fertilizers are reduced by 23.75% and 16.5% respectively.

In addition, because chloropicrin replaces the main component of traditional fumigant, methyl bromide, which destroys the ozone layer, it is also of great significance for the protection of the ozone layer.

(subhead) Prevention and control of soil-borne diseases is less than 1%. There is a long way to go to control soil diseases.

"at present, this technology has been tested and demonstrated in more than 10 provinces in China, including Shandong, Hebei, Beijing, Tianjin, Sichuan, Chongqing, Liaoning and Inner Mongolia. It has been widely used in ginger, strawberries, traditional Chinese medicine, facility vegetables, potatoes, flowers and other facility crops with remarkable results. According to preliminary estimates, the annual increase in economic benefits is more than 3 billion yuan. " Chen Mengshan, secretary of the party leading group of the Chinese Academy of Agricultural Sciences, pointed out.

Chen Mengshan told reporters: at present, China's technology for the prevention and control of soil-borne diseases is close to the international advanced level, which has effectively supported the development of China's facility agriculture, increased farmers' income, and has been welcomed by local farmers.

Cao Youyi, a strawberry grower in Pinggu, Beijing, last year used land fumigation technology to prevent and control soil-borne diseases. The strawberries in his three sheds (2.4mu) earned 210000 yuan, while his neighbors did not use this technology. The strawberry greenhouse suffered from soil-borne diseases.

It is worth mentioning that experts have found that there is no secondary pollution in soil fumigation with chloropicrin at present, and long-term studies in the United States and Canada have also shown that chloropicrin soil fumigation has no pollution to groundwater. This technology is widely used in the United States, Australia, Spain, Japan and other developed countries, and has been widely used in the United States for more than 60 years.

At present, 45 million mu of facility agriculture in China, half of which have been planted with the same crop in the facility for more than 5 years, will have a high incidence of soil-borne diseases, but the land area used for the prevention and control of soil-borne diseases is less than 200000 mu, accounting for less than 1%. There is a long way to go to strengthen the prevention and control of soil-borne diseases.