Fe is one of essential trace elements for plants and crops. Crop ferrous sulfate deficiency would cause leaves yellowing, premature, even cause yield and quality declines.
The common factors of plant ferrous deficiency as bellow:
1. High PH value of Soil:
High PH value of Soil would make ferrous to hydrolysis and precipitate. Consequently, low iron changes to high iron that cause the effectiveness of iron decrease. This case often happens in lime soil.
2. Excessive bicarbonate:
On one hand, excessive bicarbonate will raise soil PH value, on the other hand ,it hinders the ferrous transportation within plant's body which will cause plant physiological unbalanced and ferrous inactive. This case happens in lime soil and alkali soil.
3. Soil contains too low organic matter:
It is very easy for soil that contains low organic matter to cause plants ferrous deficiency. Usually use ferrous sulphate heptahydrate adjust for it.
4. High content of phosphorus, manganese or zinc in Soil:
Soil with high phosphorus, manganese or zinc may cause ferrous deficiency, especially after the soil spreaded excessive phosphate fertilization.
5. Sandy soil:
This kind of soil contains low ferrous that’s not enough for crops to absorb.
The typical symptoms of ferrous deficiency appears that mid-upper leaves lost green, often starting with veins lost green and leaves still keep green. With deficiency become serious, blades gradually turned white and veins become yellow. The most serious symptom would be that the brown spots appear on leaves and organization necrosis till leaves die.
To treat crop ferrous deficiency, people generally apply foliar spraying. In regions that ferrous deficiencies occur seriously, it’s must combined with ferrous fertilizer treatment. Common ferrous fertilizer are ferrous sulfate, ferrous ammonium phosphate, and ferrous synthetic complexation such as citric acid iron, EDTA-Fe and EDDHA-Fe, etc. In most cases, soil fertilizing is not very effective, mainly because the ferrous will soon turn into hard dissolved oxide. In order to improve the iron fertilizer effect, just mix ferrous fertilizer with organic fertilizer, and fertilize ferrous sulfate in trips or holes.
