When will winter wheat be topdressing

Winter wheat should be fertilized at seedling stage, overwintering stage, returning to green stage, jointing stage, booting stage and after heading. Farm manure was applied at seedling stage, ammonium bicarbonate or urea from overwintering to booting stage, and urea after heading. If the basal fertilizer and seed fertilizer are sufficient, there is no need to topdressing at the seedling stage; if the seedling fertilizer has been applied, the overwintering fertilizer can not be applied; if the basal fertilizer is sufficient and the tiller is strong, it is not suitable to apply green fertilizer.

1. Topdressing at seedling stage: generally, at the early tillering stage of emergence, 75-150 kg of ammonium bicarbonate or 45-75 kg of urea or a small amount of human feces and urine are applied per hectare. For wheat fields with sufficient base fertilizer and seed fertilizer, topdressing is not necessary at seedling stage.

2. Topdressing in overwintering period: combined with freezing water and topdressing in the north, nitrogen fertilizer can be applied before and after Lesser Snow, 75-150kg of ammonium bicarbonate or 45-75kg of urea per hectare, and overwintering fertilizer can not be applied for those who have applied seedling fertilizer.

3. Topdressing during the return to green period: 225-300 kg of ammonium bicarbonate or 45-75 kg of urea per hectare should be applied more than 6 cm deep. It is generally not suitable for wheat fields with sufficient base fertilizer and strong tillers before winter.

4. topdressing at jointing stage: nitrogen fertilizer is the main fertilizer. Over-prosperous seedlings should not be topdressing nitrogen fertilizer; strong seedlings should apply a small amount of nitrogen fertilizer, 150-225 kg ammonium bicarbonate or 45-75 kg urea per hectare, combined with phosphate and potassium fertilizer, 75-150 kg calcium superphosphate and 45-75 kg potassium chloride per hectare; weak seedlings should apply more available nitrogen fertilizer, 300-600 kg ammonium bicarbonate or 150-225 kg urea per hectare.

5. Topdressing at booting stage: mainly applying nitrogen fertilizer with less amount, generally applying 75-150 kg ammonium sulfate or 45-75 kg urea per hectare.

6. Topdressing after heading: certain elements such as nitrogen, phosphorus and potassium are needed. 750 litres of urea with a concentration of 1% and 2% can be sprayed per hectare in wheat fields with yellowing leaves and premature senescence, and 750 litres of potassium dihydrogen phosphate solution with 0.2% concentration can be sprayed per hectare in wheat fields with green leaves and a late ripening trend.