What fertilizer does plant leaf become yellow lack?
The reasons are complex, but may also be caused by lack of sunlight and water shortage.
 
1. The plant is short of nitrogen, the old leaves begin to turn yellow first, and then gradually turn yellow from bottom to top. In time, nitrogen fertilizer such as urea, ammonium bicarbonate and ammonium sulfate can be added from the root or leaf to make the leaves turn green.
2. Crop lacks phosphorus, whole plant can turn dark green, and do not have burnish, leaf also can turn yellow, add in time the phosphate fertilizer such as calcium superphosphate, can promote leaf to restore burnish.
3 crops, fruit trees, vegetables and flowers lack potassium, leaf will be uneven, leaf edge may also appear yellow hair dry phenomenon, timely supplement plant ash, potassium sulfate or potassium chloride and other potash fertilizer, can alleviate symptoms.
4 plant iron deficiency, young leaves and old leaves appear at the same time yellowed phenomenon, young leaves of mesophyll yellow, vein green, the formation of network yellow leaves, general irrigation ferrous sulfate, but the concentration should not be too large, can be applied by stages, to avoid burning roots.
5. Calcium deficiency crops, young leaves yellow and curly phenomenon, can be applied into the crushed egg shell and other calcium fertilizer, reduce the harm.
6 plant magnesium deficiency, leaves back green yellow, finally dry and die, timely application of calcium magnesium phosphate fertilizer, magnesium sulfate fertilizer.
7 crops lack of sulfur, leaf veins yellow, timely application of ammonium sulfate, etc., to make the leaf green.
8. Strong alkaline soil, there will also be yellow leaves, can be applied to rice water, ferrous sulfate and other acid fertilizer, change the soil environment.
9. Too much water or water, young leaves of plants turn yellow, excessive drought, old leaves began to turn yellow, from bottom to top gradually aggravating, and even in the whole plant dead, adjust the soil moisture, can effectively remedy.
10. Too much fertilization or too short interval will cause fertilizer damage. Young leaves will appear uneven, but leaves will be thick and shiny.
In addition, some plants in strong light irradiation, insufficient light, high temperature and high humidity and other natural environment will also appear leaf yellowing, according to the actual situation to judge the cause of formation, can also take appropriate measures to prevent.
 

Source: agricultural materials and technology