China uses a large amount of fertilizer, resulting in waste of resources and environmental damage. In the view of domestic and foreign experts, it is impossible and unscientific to give up chemical fertilizers, but China must improve the use efficiency of chemical fertilizers.

At the "IFA (China) Fertilizer Sustainable Development Management Forum" held from September 16 to 17, Zhang Fushuo, a professor of China Agricultural University [Weibo], commented on the First Financial and Economic Daily that China's food production mainly depends on high input (of fertilizer and other products), which is not good for the environment, and this food production mode is not sustainable.

China consumes more than 1/3 of global fertilizer

China is a large country in fertilizer production and consumption, with the total output and consumption of fertilizer accounting for more than 1/3 of the world. Excessive application of chemical fertilizer has become the curse of Chinese agriculture.

Heavy use of chemical fertilizers will lead to a series of negative consequences. Long Wen, deputy director of the Agricultural Means Bureau of the All-China Federation of Supply and Marketing Cooperation, believes that the excessive use of chemical fertilizers not only wastes non-renewable energy and resources such as coal and phosphate rock, but also increases the domestic dependence on sulfur and potassium. In addition, the increase of greenhouse gas emissions from agricultural sources and river pollution.

In 2010, the Ministry of Environmental Protection issued the Bulletin of the First National Pollution Source Survey. If the proportion of pollution sources is measured by COD (chemical oxygen demand) emissions, agriculture will surpass industry as a major pollution source.

Zhang Lijun, then deputy minister of the Ministry of Environmental Protection, said that at present, the pollution problem of agricultural sources in China is relatively serious

Zhang Fushuo said, for example, that a large amount of agricultural fertilization led to a 0.5 unit drop in the PH value of farmland nationwide, and the soil was generally acidified. Acidification, first of all, causes poor crop growth. Secondly, it causes the occurrence of diseases and pests, heavy metals exceeding the standard, and food safety problems.

Ineffective use is the root cause

The root cause of the large amount of fertilizer is the low use efficiency.

The rice yield per unit area in China is similar to that in Japan, but the amount of nitrogen fertilizer used is three times that in Japan and twice that in South Korea. In addition to the poor soil conditions, the more important is the unreasonable use of fertilizer.

Gao Xiangzhao, director of the water-saving department of the National Agricultural Technology Extension Service Center, believes that China's fertilizer consumption is more than that of other countries, which is related to the planting system. Due to the high multiple cropping index of many cash crops in China, the amount of fertilizer is directly large. In addition, the lack of water resources, especially the mismatch between water resources and agricultural production, has also caused a large waste of fertilizer.

For example, in recent years, China's main grain production areas are shifting from the south to the north. And the north is the area with serious shortage of water resources. What's more, in agricultural production, the mutual matching of water and nutrients is rarely considered. Unreasonable water use, especially flood irrigation, has resulted in a large amount of fertilizer waste.

It is imperative to improve the efficiency of fertilizer use, whether from the perspective of agriculture, economy or environmental protection.

In addition to chemical fertilizers, the growth rate of traditional agricultural inputs such as irrigation, plastic film and pesticides in China's agriculture is also much faster than the growth rate of grain production.

Zhang Fushuo believes that China's food is produced entirely on the premise of high investment and no special benefits to the environment. This food production mode is unsustainable.

Long Wen suggested that we should further deepen the work of soil testing formula, accelerate the change of farmers' extensive fertilization concept, and improve farmers' scientific fertilization level. "The government should establish a sound policy support system and technological innovation system, form a sustainable new system for the production, marketing and use of fertilizer, and promote the nationwide precision service of agricultural materials."

The International Fertilizer Industry Association (IFA) is developing a nutrient management project. Charlotte Hebebrand, the secretary-general of the International Fertilizer Industry Association (IFA), described how to teach farmers how to use the right nutrients at the right time and in the right proportion. Because, in different agricultural areas, the specific characteristics of crops and soil are different. This is of great significance in China, which has many small farmers.

"How to effectively and scientifically manage water and fertilizer comprehensively should be the key to further improve fertilizer utilization in China," Gao Xiangzhao said.

(Sina Agriculture)