Why did the soil turn red?
Generally, there are three reasons for soil redness:
1. The soil becomes acidic.
Soil acidification means the decrease of soil PH value. After more than ten years of cultivation in some northern regions, the soil PH value even drops below 3.0. However, most of our crops are suitable for growing at a PH range between 5.5 and 7.5.
The reason for soil acidification is the application of a large number of physiological acid fertilizers, such as potassium chloride, potassium sulfate, ammonium chloride, ammonia sulfate, etc., together with the high temperature and humidity inside the shed, the soil is rarely leaching by rain. With the increase of cultivation years, the accumulation of acid root ions in surface soil becomes more and more serious, resulting in soil acidification.
2. Soil salinization.
In fact, fertilizer is inorganic salt. As a result, the salinity of greenhouse soil rises. After water evaporates, the salinity stays in the soil surface and gradually turns red after oxidation.
3. Soil eutrophication.
The reason for this phenomenon is improper field management, which results in soil hardening, impervious water and excessive evaporation, resulting in the concentration of salt ions on the soil surface. Due to the concentration of salt on the soil surface, it is suitable for some algae to survive. If the soil surface becomes dry, the algae will die, and the algae residues will show red color.
How to solve the redness of soil surface?
The first, want reasonable fertilizer.
Reduce the use of chemical fertilizers, combined with the application of organic fertilizer and biological fertilizer. Improving the physical structure of soil. The data showed that soil pH value had a great influence on the effectiveness of fertilizer application. For example, nitrogen is most effective in the range of ph6-8 in soil. Phosphorus is most effective at pH6.5-7.5. Potassium, calcium, magnesium and sulfur are most effective at pH6-8. Iron, manganese, copper, zinc, boron and other trace elements are generally most effective under acidic conditions.
Reduce the use of compound fertilizer, use more water-soluble fertilizer, improve fertilizer utilization.
Secondly, irrigation methods should be reasonable.
Changing flood irrigation to drip irrigation can save water and fertilizer and reduce soil damage at the same time.