Expert: Fertilizer is a good thing, "fertilizer dependence" is not a good thing

Rely on chemical fertilizers to ensure food production Linyi fertilizer Copyright

It is understood that before the 1960s, China relied on organic fertilizers to maintain soil fertility, the application of chemical fertilizers was very low, and crop yields were very low. Since the 1960s, China has only begun to develop nitrogen and phosphorus fertilizers, while importing nitrogen fertilizer. Linyi Fertilizer Network Copyright

Ju Xiao, a professor at the College of Resources and Environment of China Agricultural University, said in an interview with the Economic Information Daily that chemical fertilizer itself is a good thing. In China, the contribution rate of chemical fertilizer to food production has reached 30% to 50%. China's land fertility is generally low, and the multiple cropping index is high. The average piece of land in the country is to be planted for one and a half seasons, unlike most Western countries that only plant one season a year. In this case, the fertility of the soil itself cannot meet the nutrient requirements of the crop, and the fertilizer must be applied, otherwise the yield will not reach the target. Linyi Fertilizer Network Copyright

Ju Xiaolan believes that some farmers have “fertilizer dependence”, mainly because of the increase in labor costs, crop cultivation has become simple and extensive, not as intensive as in the past. Some farmers think that when they plant crops and sprinkle with chemical fertilizers, they can go out to work and rely entirely on fertilizers to ensure food production. Linyi Fertilizer Network Copyright

However, the role of fertilizers in increasing crop yields is limited. According to the analysis of Huang Zongzhi, author of China's Recessive Agricultural Revolution, the “green revolution” (mainly scientific selection and use of chemical fertilizers), which was widely praised in the second half of the 20th century, has an annual growth rate of only 2%. 3%, it takes 20 to 30 years to increase production by a factor of two. Linyi Fertilizer Network Copyright

Ju Xiaolan believes that “fertilizer dependence” is wrong to a certain extent, because crop production is systematic engineering, including farming, plant protection, irrigation, etc. The application of chemical fertilizer is only one of the links. To achieve the agricultural production targets and economic benefits, agricultural production must achieve large-scale, standardized management, and it is difficult to achieve increased production and high yields simply relying on chemical fertilizers. Linyi Fertilizer Network Copyright

High total amount of fruits and vegetables, especially serious Linyi Fertilizer Network

China's annual fertilizer use is more than 54 million tons, mainly including nitrogen, phosphate and potash, of which the use of nitrogen is about 33 million tons. In 2009, China's fertilizer use per hectare was 341 kg, higher than the rest of the world. Linyi Fertilizer Network Copyright

“There is a problem of excessive use of chemical fertilizers in China.” Ju Xiaolan said that the differences between the various blocks are also very large, 1/3 of the plots are excessive, 1/3 of the plots are reasonable, and 1/3 of the plots are insufficient. The central and eastern regions are higher than the northwest, southwest, and northeast regions, especially in areas with high levels of agricultural production in the north and lower reaches of the Yangtze River. Linyi Fertilizer Network Copyright

Ju Xiaolan said that from the perspective of crop types, excessive use of chemical fertilizers is concentrated in vegetables and fruit trees, accounting for a high proportion of total fertilizer use. For example, the application of nitrogen fertilizers to vegetables accounts for more than 20%. Linyi Fertilizer Network Copyright

A few days ago, some media reported that in Shouguang, Shandong, which is known as the “vegetable basket” in China, the amount of chemical fertilizer input in vegetable greenhouse cultivation mode is four times that of the national average due to perennial planting and continuous cultivation. Linyi Fertilizer Network Copyright

Ju Xiaolan believes that the main problem of excessive use of chemical fertilizers is pollution of water bodies and the atmosphere. Excessive nitrogen and phosphorus mostly flow into the water body, causing eutrophication of the water body; ammonia emissions cause air pollution, and nitrous oxide emissions cause a greenhouse effect. This is a disruption to the entire ecosystem and will add a lot of social costs. Linyi Fertilizer Network Copyright

For the quality of agricultural products, Ju Xiaolan believes that the excessive use of chemical fertilizers has little effect, mainly causing the accumulation of nitrates in leafy vegetables. Excessive use of chemical fertilizers can also increase the pests and diseases of crops, thereby increasing the use of pesticides and leading to more pesticide residues. Linyi Fertilizer Network Copyright

The amount of nitrogen fertilizer can be reduced by 30% .

Ju Xiaolan believes that to ensure the supply of agricultural products, the application of chemical fertilizers cannot be avoided. Ecological agriculture and organic agriculture are only suitable for a small part of agricultural products, and most of them have to be supplied through conventional agriculture. The key issue is how to properly fertilize, ensure production and reduce environmental pollution. Linyi Fertilizer Network Copyright

“First of all, do not abuse chemical fertilizers, and then through technological innovation, improve the utilization rate of chemical fertilizers.” Ju Xiaoyan put forward three suggestions: First, chemical fertilizers should be combined with organic fertilizers (including human and animal manure and crop straw), and organic fertilizers should replace some fertilizers. Can improve soil quality and form a virtuous circle. Linyi Fertilizer Network Copyright

The second is to apply fertilizer according to the target yield, determine the amount of fertilizer application in a simple way, and achieve total control. Linyi Fertilizer Network Copyright

The third is chemical fertilizer modification. By adding the “nitrification inhibitor” commonly used in foreign fertilizers to transform the original quick-acting fertilizer into stable fertilizer, the nitrogen fertilizer utilization rate can be improved on the basis of ensuring the yield, and the nitrous oxide is significantly reduced. Emissions and nitrate contamination. If nitrification inhibitors are used in most of the nitrogen fertilizer in the future, the nitrous oxide reduction effect can reach 70%. Linyi Fertilizer Network Copyright

According to Ju Xiaowei's estimate, the total amount of nitrogen fertilizer used in China can be reduced by 30%, maintaining between 23 and 25 million tons, so that grain production will not be greatly affected, and the environment can be greatly improved. Linyi Fertilizer Network Copyright

The National Soil and Fertilizer Work Conference held by the Ministry of Agriculture in early July proposed that during the “Twelfth Five-Year Plan” period, China will vigorously promote scientific fertilization, and the area coverage of soil testing and formula fertilization will reach 60%. The whole village, the whole township, and the whole county will promote soil testing and fertilization. To the field; optimize the allocation of fertilizer resources, demonstrate the promotion of new fertilizers according to local conditions; and improve the method of fertilization. We will strive to increase the utilization rate of fertilizer by 3 percentage points, and strive to increase the utilization rate of organic fertilizer resources such as livestock and poultry manure by 10 percentage points, and increase the rate of returning straw to the main crops by 10 percentage points to promote the agricultural ecological environment and the quality and safety of agricultural products. Linyi Fertilizer Network Copyright

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