Excessive use of fertilizers does not necessarily
[2018-12-24]
A large number of facts show that the yield of vegetables is not proportional to the amount of fertilization. The multi-application of fertilizers is a misunderstanding of many vegetable farmers. The total salt content of vegetables required for normal growth of vegetables is 2000×10-6. 3000 × 10-6, more than 6500 × 10-6, the root system will appear reverse osmosis and die. In particular, the temperature in the greenhouse is high, the humidity is high, the organic fertilizer is decomposed quickly, the fertilizer is highly effective (phosphorus is 2 to 3 times higher than the open field), and the amount of nitrogen volatilization is large. If the fertilizer is excessive, it is easy to cause gas damage. At present, the greenhouse soil in some areas is brick red, and the growth potential of vegetables is caused by excessive soil ion concentration due to excessive application of chemical fertilizer.
Excessive application of chemical fertilizers can also cause imbalances between nutrients. If the phosphorus is high, the zinc is insufficient, and the zinc deficiency in the soil must be iron deficiency. Excessive application of high-nitrogen and high-potassium fertilizers will inhibit the absorption of calcium ions in the soil by vegetables, causing calcium deficiency, which will affect the normal results of vegetables.
In fact, there is a limit to the amount of organic fertilizer required by vegetables. It is not the more organic fertilizers are applied. For greenhouses planted for more than 3 years, the application rate of organic manure such as chicken manure and duck manure should be controlled at about 3,000 kg per mu. For new sheds, organic fertilizer can be added as appropriate. For the old sheds planted for many years, it is necessary to pay attention to the application of humic acid fertilizer and biological bacterial fertilizer to increase the soil carbon-nitrogen ratio, loose soil ventilation, and salt damage. At the same time, according to crop demand, appropriate supplementation of trace elements such as boron and zinc to balance soil nutrition.
