First, the lack of nitrogen
Symptoms: The leaf color of the old leaves of the barley is yellowish green, the old leaves are dry, and the whole leaves are yellow; the stems are slender and erect, sometimes lavender, less tillers, and small ears.
Control method: It is recommended to apply compost or organic fertilizer prepared by enzyme bacteria. Seedling stage 667m2 carbon ammonium 10-15kg, point application or water with fertilizer, medium-term application of urea 3-8kg, late spraying 25 urea solution. Conditional autumn sowing time base long-acting ammonium bicarbonate once, can meet the requirements of conventional autumn base fertilizer, spring application of fertilizer, summer application of spike fertilizer.
Second, phosphorus deficiency
Symptoms: The tillering stage, jointing stage or booting stage, the leaves are dark brown and slightly purple, especially the purple part of the leaf sheath is obvious. It extends from the tip to the base, the plant is thin, the tiller is less, the cold resistance is poor, and it is easy to be frozen.
Control method: avoid phosphorus deficiency 667m2 application of calcium phosphate 15-25kg, acid soil can be applied calcium magnesium phosphate fertilizer, late spraying 0.2% -0. 5% potassium dihydrogen phosphate.
Third, the lack of potassium
Symptoms: from jointing to booting stage, the leaves are blue-green, the old leaves turn yellow, the tip and leaf margins are yellowed and burnt, the yellowing at booting stage is more obvious, the white spots appear on the leaves, the leaves are covered, and the angle between the leaves and the main stem is large. Severe heading is difficult or early death, the grain is small and shrinks.
Control method: Apply 5-10kg of potassium fertilizer per 667m2, and apply the fertilizer once or twice to the base fertilizer. Spray 0.5% potassium chloride or 5%-10% grass ash extract in the later stage.
Fourth, manganese deficiency
Symptoms: The new leaves in the seedling stage are soft and draped, and the new leaves are striped and chlorotic, and the yellow-green to yellow-yellow veins are still green.
Control method: 0.5-1kg of manganese sulfate per 667m2 mixed with organic fertilizer as base fertilizer, can also be dissolved with 40-80g manganese sulfate plus a small amount of water, mixed into 10kg of seeds, dried and sown. In addition, 0.05%-0.1% manganese sulfate solution can also be sprayed at the seedling stage and the pre-flowering stage.
Five, iron deficiency
Symptoms: The lower leaves are green, gradually fade upwards, and the new leaves are yellowed.
Control method: 4-5kg of ferrous sulfate is applied to the base fertilizer.