Recently, the Publicity Department of Yiyang Municipal Party committee of Hunan Province said that in response to the report that "Zhenxiong County, Zhaotong City, Yunnan Province, destroyed a batch of rice with heavy metal exceeding the standard from Yiyang, Hunan Province", Yiyang City decided to put seven enterprises involved in the investigation through investigation and verification of the relevant situation.

Just three years ago, some enterprises sold 1440.25 tons of rice with excessive cadmium to many provinces and cities, including Zhaotong, Yunnan Province. In fact, there are not only cadmium rice, cadmium wheat and other food products polluted by heavy metals, but also a lot of punishments and accountability from regulatory authorities and circulation basins.

To this end, Party Yongfu, a well-known expert in soil management, said: "only starting from the production field and keeping cadmium rice from growing can we eradicate this stubborn disease, not just control food security in the field of circulation and sales."

According to Dang Yongfu, China is currently implementing the "double reduction" technology of chemical fertilizer and pesticide, but the use of chemical fertilizer in agricultural production is still more than 30% of the world's total, and the cultivated land area polluted by heavy metals such as cadmium, arsenic, chromium and lead is expanding. Cadmium rice appears in China. Some experts think that overuse of phosphate fertilizer is an important reason. When the problem rice appeared in 2013, there were relevant experts who believed that there were no heavy metal enterprises around the problem rice, and the cadmium in the rice exceeded the standard or was brought in by fertilizer.

In addition, the mining area pollution is also the most serious reason for the excessive cadmium in rice in Hunan Province. If the waste containing cadmium can not be separated and recycled well, whether it is incinerated or buried, it will lead to soil cadmium pollution. The soil pollution caused by the solid waste containing cadmium is also one of the reasons for the occurrence of cadmium rice.

In addition, some farm waste also contains a certain amount of heavy metals. It is reported that the excrement of these farms, which was fermented, was a good soil fertilizer, but also resulted in the withering of plants. The reason may be that the additives in feed may contain heavy metals which are not easily digested by livestock and poultry.

Dang Yongfu explained that cadmium is easily absorbed by rice and accumulates in rice grains, which is transmitted through the food chain, posing a serious threat to human health. When people eat the food containing cadmium, it will accumulate in the kidney, lung, bone and liver. Long term accumulation will cause poisoning, damage to the kidney, lead to bone lesions, and lead to bone pain.

Cadmium can enter the environment through waste water, waste residue and waste gas, then enter the soil and farmland through water source, and finally enter the food chain.

"To fundamentally solve food security problems such as cadmium rice, we must start from the prevention and control of soil pollution at the source." "By building a system engineering system of 'process agriculture' to form a whole process management model of agriculture, we can solve the current fragmented agriculture and promote the transformation and upgrading of chemical agriculture," said party Yongfu

According to his own practical experience, Party Yongfu believes that we need to do a good job in the following aspects: set up the concept of "quality red line" of cultivated land, and lead scientific and technological innovation with policies to make up for the shortage of soil. He believes that as a resource, cultivated land has both the concept of quantity and the requirement of quality. The cultivated land quality protection should be regarded as a basic, public welfare and long-term work throughout the whole process of cultivated land protection, and be included in the assessment objectives of governments at all levels. The "hard bar" of cultivated land quality protection should be defined, and the "hard constraint" of cultivated land quality protection should be strengthened, so that the quantity of cultivated land will not be reduced and the quality will be improved. The quantity, quality and ecology of cultivated land should be considered as a whole from the national level The unity of the three elements can realize the fundamental transformation of cultivated land from the simple quantity of cultivated land to the quantity, quality and ecology of cultivated land.

"In addition, we should build a scientific and technological innovation system to support the quality protection of cultivated land, provide strong technical support for the quality protection of cultivated land; integrate soil fertilizer and cultivation technology into agricultural machinery operation, and promote the green, high-yield and efficient technology mode." "According to different situations, we will adopt stubble, tree planting, rotation and other methods to control soil pollution by adjusting structure, increase investment in scientific and technological innovation, accelerate demonstration, promotion and application of mature and applicable green technologies and green varieties, realize coordinated development of production and ecology, and improve quality, efficiency and competitiveness," said Dang Yongfu

Source: Science and Technology Daily