Is it the fault of chemical fertilizer that melons and vegetables "go sour"?

Is the light taste of ⒈ melons and vegetables related to chemical fertilizer?

Scientific fertilization does not affect the taste of fruits and vegetables, the key is not to overuse and rely too much on chemical fertilizer

Some people say that now the fruits are not sweet and the vegetables are tasteless. This is all because of the use of chemical fertilizers. Is that so?

Zhang Fusuo: whether vegetables or fruits are delicious or not has something to do with their own varieties, planting methods, soil climate and other factors. Fertilizer is only one aspect. It is recognized that scientific fertilization will not only have no negative effect on the taste of fruits and vegetables, but also improve the quality of crops. For example, nitrogen fertilizer can increase protein content; potassium fertilizer can increase sugar content, VC content; phosphate fertilizer can promote early maturity, increase oil content and so on. But if there is too much fertilizer, just like people eat too much, the metabolic balance will be disrupted, resulting in a decline in the quality and taste of fruits and vegetables.

How do farmers fertilize now?

Gong Jinxing: my family has planted 11 mu of watermelons and should apply fertilizer three times a season: the first time is the base fertilizer before and after the Qingming Festival, with 4 square soil fertilizer and 50 jin chemical fertilizer for 1 mu; 50 jin compound fertilizer for 1 mu after 40 days; and 30 jin for 20 days before harvest. According to the calculation, one mu of watermelon needs one and a half bags of chemical fertilizer.

Fan Yongqiang: generally speaking, the amount of chemical fertilizer used in Gong Jinxing's melon field is not high, but structurally, it can further reduce nitrogen and increase the proportion of organic fertilizer and potash fertilizer. In our promotion at the grass-roots level, we found that fruits and vegetables and other cash crops generally have the phenomenon of large amount of nitrogen fertilizer and less organic fertilizer, and organic fertilizer is a key factor to improve the taste of fruits and vegetables.

Is it okay not to use chemical fertilizer?

Gong Jinxing: "A single flower in a crop depends entirely on fat." Now the land is more and more greedy, knowing that it is not good to use more chemical fertilizer, but can not stop. The average yield of watermelons I planted is only more than 6000 jin per mu. Once the chemical fertilizer comes down, the yield will certainly follow.

He Caiwen: agricultural production is inseparable from chemical fertilizer, but it can not be completely dependent on chemical fertilizer. Chemical fertilizer is the "grain" of crops, and studies have shown that its contribution to grain production has reached 30%, 50%. For example, vegetable crops generally have a short growth period, with a yield of more than 10,000 jin per mu. If there is not enough fertilizer support, a crop will consume the nutrient accumulation of the land for many years, and a bumper harvest is unthinkable. Therefore, in order to have a correct understanding of chemical fertilizer, scientific and rational use is the key.

Do not use chemical fertilizer for green products?

Zhang Fusuo: the elements of nitrogen, phosphorus and potassium in chemical fertilizers are natural substances in nature, not toxic substances. The A-level standard of green food in China stipulates that chemical fertilizers can be used to a limited extent. European organic agriculture regulations allow the use of phosphate rock and potassium ore.

What is the overall situation of chemical fertilizer use in China?

He Caiwen: the overall use of chemical fertilizer in China is still relatively high. According to statistics, the annual use of chemical fertilizer in the country is more than 58 million tons, ranking first in the world, but the utilization rate in the current quarter is only 33 percent, about 20 percentage points lower than that of developed countries.

At present, the main problems are as follows: first, the excessive application of chemical fertilizer, especially fruit and vegetable crops, has developed rapidly in recent years, and this problem is more prominent. Second, the application structure is unreasonable and the proportion of nitrogen, phosphorus and potassium does not match the soil demand of crops. Third, the utilization rate of organic fertilizer resources is low, and the actual utilization is less than 40%. Fourth, the way of fertilization is backward, traditional artificial fertilization is still dominant, and mechanical fertilization only accounts for about 30% of the area of major crops.

What is the impact of excessive fertilization on ⒉?

It brings about soil degradation problems such as non-point source pollution, soil acidification and so on. Reasonable "weight loss" will not affect the supply of agricultural products.

What are the effects of excessive application of chemical fertilizer?

Zhang Fusuo: excessive fertilization not only affects the quality of agricultural products, but also leads to soil degradation problems such as soil acidification and secondary salinization. For example, soil acidification, it takes tens of thousands of years for the natural soil pH value to decrease by one unit, while the cultivated land in China has decreased by 0.5 unit in 30 years. Studies have shown that when the soil pH value decreases by one unit, the activity of heavy metal cadmium will increase by 100 times, increasing the risk of heavy metal pollution.

Fan Yongqiang: we have tested some orchards in Jiaodong area and found that the pH value dropped to 4.5. Under such conditions, the proportion of soil nutrients was out of balance, the number of diseases and insect pests increased, and crop yields were reduced by more than 30%. In addition, excessive fertilization will also cause soil consolidation, soil fertility decline, resulting in non-point source pollution, affecting the quality and safety of agricultural products. For example, a large amount of partial application of nitrogen fertilizer will cause a large amount of nitrate accumulation in plants, resulting in an increase in nitrate content.

He Caiwen: rational fertilization will not cause soil safety problems. The experimental results of Lobsang Experimental Station in England for 170 years show that the scientific application of chemical fertilizer will not cause the decline of soil quality, and can promote organic matter by inorganic and improve the quality of cultivated land.