Type, nature and application of potassium fertilizer

1. Symptoms of potassium deficiency in plants:

First of all, the leaf margin of the old leaves is yellow and then browned and scorched, and the leaves appear brown spots or patches, but the middle of the leaves and the veins remain green. With the aggravation of potassium deficiency, the whole leaves become red-brown, or dry, necrotic, and shedding. Some crop leaves are bronze in color, the downward curl, leaf surface mesophyll tissue convex, and leaf veins subsidence. Potassium deficiency in different crops. General potassium deficiency symptoms in the late growth period, therefore, to prevention.

2. Pot a s s iu m ch lori de (KCl)

Potassium chloride is mainly made from carnallite (KCl·MgCl₂·H₂O), potassium ore, and salt brine (NaCl·KCl) processing. chlorine Potassium oxide is a white or light yellow, purple-red crystal; The content of K₂O is 60%, it is easily soluble in water and has a quick effect on crops. There is a certain hygroscopicity, long-term storage will caking; It is a chemically neutral and physiologically acidic fertilizer.

    2. Application technology

Potassium sulfate is mainly aluminate [K₂SO₄.Al₂(SO₄)₃.4Al(OH)₃], leonite(K₂SO₄Mg SO₄) Made by calcination. 

Potassium sulfate is a white or light-yellow crystal; K₂O content is 50-52%, easily soluble in water, it has a quick effect on crops

less hygroscopic and difficult to agglomerate; thermoneutral, physiological acid fertilizer. 

    application process:

① It can be used as base fertilizer and topdressing, and field crops generally apply 4-6kgK₂O per mu to be more economical and effective. The application of base fertilizer on neutral soil should be combined or mixed with organic fertilizer and phosphate rock powder, which can prevent soil acidification and promote the availability of phosphorus in phosphate rock powder. Lime should be applied to acid soil.

②K₂SO₄  should be used as seed fertilizer and topdressing, and the amount of seed fertilizer is 1.5-2.5kg/mu K₂O. The concentration of topdressing outside the root is 0.5-1%.