Fertilizer used to be a "grain" of food, and now is often labeled as contaminated. In the eyes of some people, the use of chemical fertilizers has led to environmental degradation, and even those who believe that all kinds of fertilizers produced by the agricultural products are cheap and inferior, and even unsafe food. Chemical fertilizer is an important material to ensure food security, one-sided accusations of fertilizer will mislead the normal development of an industry. These three views are extremely popular today, but is this really the case?
Point of view: the use of chemical fertilizer really excessive?
Is there any excess amount of fertilizer used in China? Whether or not there is abuse of universal phenomenon? This problem seems to have no room for discussion, because in many people's view, the use of chemical fertilizer has become a consensus.
Indeed, compared with developed countries, there is a certain gap in the utilization rate of fertilizer in China, fertilizer waste is also an objective existence, but the specific issues need to be specific analysis, a stick is not a scientific attitude to death.
On the one hand, there are objective reasons for the low utilization rate of fertilizer in china. Chinese has the largest population in the world, but 70% of the arable land belong to the middle and low yielding fields, to make 1 billion 400 million Chinese not hungry, the only way is to increase the yield, which is caused by external factors of the amount of fertilizer is too large.
On the other hand, if careful study, excessive fertilizer phenomenon also need to be treated differently in different regions and crops. According to 2014 data, when the sown area of 2 billion 482 million acres, the same year the amount of nitrogen fertilizer is about 32 million 390 thousand tons, down, about an acre of land of about 12 kg and a half, which can be considered excessive? So some experts, do not rule out individual areas, individual crops, but in general we are still within the range of reasonable fertilization.
Point two: haze can blame fertilizer?
In recent years, the haze has become the focus of attention. And the solution about the causes of haze, it should be said is still under study, but unfortunately, chemical fertilizers are also "shot", many people think that the causes of haze, chemical fertilizer can not get away.
According to the results of the current study, the haze caused by PM2.5 two particles, 40% organic compounds, ammonium sulfate, ammonium nitrate is the 15%, and the other is the carbon element of the 14%, and the other is a factor of 31%. Among them, ammonium sulfate and ammonium nitrate accounted for nearly half of the proportion. It is generally believed that the sulfur in ammonium sulfate is mainly derived from coal, especially scattered burning coal, ammonium nitrate mainly from motor vehicle emissions of nitrogen oxides, while 95% of ammonia was determined from agriculture.
But the problem is that Chinese haze occurred in the winter, but this season is a period of low value of farmland ammonia emissions, so simply in the haze of ammonia due to fertilizer, this view is not a tenable. Of course, the shirking negative effect of environment is not to say that caused by chemical fertilizers. It is estimated that each year by the agricultural source of ammonia emissions to the atmosphere is 5 million 430 thousand tons, which is not only a waste of resources, energy, but also to the environment caused by the pressure, chemical fertilizers should not be reduced.
Viewpoint three: fertilizer causes soil degradation?
In the last 20 years, soil acidification has been increasing, especially in the south of Yangtze river. Soil acidification will reduce soil fertility, but also induced crop heavy metal exceed the standard.
As the input of agriculture, fertilizer is considered to be the direct cause of soil acidification. In fact, this argument also has the necessary to study. Crop growth in the root system will secrete acidic substances, and the higher the yield, the greater the amount of acid secretion. On the basis of China land barren, to protect the 1 billion 400 million Chinese clothing, only put a lot of fertilizer, improve the yield, so will inevitably lead to more and more crop acid secretion, accumulated to a certain extent, will cause soil acidification.
The logical relationship can be summed up as follows: the more fertilizer inputs, the more acidic substances secreted by the crop, which lead to soil acidification. Therefore, the fertilizer itself is not the culprit of soil acidification, the crop is less, but we can't grow crops or intentionally cut?
To solve the problem of soil acidification, but also to meet the needs of food security is a dilemma. Chemical fertilizer on the protection of high yield on the mission, the task of soil improvement is not the chemical fertilizer can bear, the need for new technology and product investment. The acidification of the play in the fertilizer, it is unworthy.