What is causing the phenomenon of crops yellow leaf? There are some factors, such as iron deficiency, magnesium deficiency, and damage of drugs, soil conditions, the lack of
organic fertilizer nutrients and so on. We should know how to solve these crops yellowing phenomenon when they occur accordingly.
Because iron element is deficient in iron, which can produce yellow leaf, need to be filled iron. A lot of vegetable farmers reflected that ferrous sulphate was applied in the soil. The problem of leaf yellow was not improved all the time.
This often happens because the yellow leaves are not caused by iron deficiency, maybe because soil conditions make iron immobilized and not absorbed by vegetables.
There are three characteristics of vegetable yellow leaves caused by iron deficiency. One is that the heart leaves turn yellow, which occurs mainly near the growth point, and the old leaves necessarily turn yellow. Second, the veins between the leaves become yellow, the veins do not change yellow or yellow time lag. Third, it is to be accompanied that leaf turning yellow and thinner, when condition becomes serious, leaf is turning decrescent and white, leaf edge is withered. For this type of iron-deficient yellow leaves, after several sprays of zinc and iron-containing leaf fertilizer, the effect is to be seen quickly and the leaves will return to green.
And the short of magnesium also can cause yellow leaf, old leaves in the middle lower part becomes yellow, which has apparent place distinction with heart leaf yellow, it can be solved by spraying leaf fertilizer containing magnesium. In northern China, magnesium deficiency of yellow leaves is rare, especially in the areas irrigating the groundwater with high degree of mineralization and high hardness.
Drugs also can cause yellow leaves, such as some vegetables are allergic to some pesticides, fungicides sensitive, after the application of drugs to cause the leaves suddenly turn yellow, which is the characteristics of the yellow leaves caused by the damage of drugs. For example, when spraying kidney bean with "anthrax fumei", the leaves will turn yellow and the flowers and pods will fall. Spraying eggplant with mancozeb will make the leaves of eggplant, the first time of application, leaf is no light, second times the leaves turn yellow, when the three times, which will be suffered the disaster seriously, almost all leaves turn yellow and fall off; spraying tomato with insecticide will make the low part leaves of aging and yellowing, or even fall of.
However, yellow leaves also often occur on clay ground, which is caused by poor permeability of clay soil. Increasing application of organic fertilizer,
NPK compound fertilizer and straw fertilizer is benefit to improve soil permeability and soil structure.
So we not only master the ways to apply fertilizer, but also know what is the high-quality organic nutrient fertilizer manufactured by the professional
organic fertilizer production line, we also should know how to improve the soil physical and chemical character by applying the organic fertilizer and
npk compound fertilizer, to provide the good environment for plant growth and development, which is the crucial factor for high-quality and high-yield crops.
