When is the best time to apply fertilizer to sorghum?

Time for topdressing sorghum

The period from jointing to heading consists of two stages: vegetative growth and growth development. It is the most vigorous period in the entire growth and development stage. Not only do the stems and leaves grow rapidly, but the plant has also entered the stage of panicle differentiation and absorbs the most needed fertilizer.

To meet sorghum's demand for cucumbers, the first fertilizer should be applied before jointing, with 10-15 kg, or 8-15 kg, of ammonium nitrate per mu; the second fertilizer should be applied during the booting stage, with 8-15 kg of ammonium nitrate per mu.

Sorghum topdressing fertilizer

1. Topdressing should be mainly with quick-acting nitrogen fertilizer, mainly applying jointing fertilizer and ear formation fertilizer. It is better to apply topdressing during the jointing stage and the flaring stage. At this time, topdressing can promote the differentiation of ears, reduce the degeneration of florets, and achieve large ears and many grains. If large-grain fertilizer is applied, and more than 15 kg is applied per mu, it should be applied in stages.

2. It is better to apply heavy fertilizer at the beginning and light fertilizer at the end for sorghum. Heavy fertilizer should be applied in the jointing stage, and light fertilizer should be applied in the heading stage. Generally, when 2/3 of the leaves are fully expanded, 5-8 kg of potassium fertilizer and 40 kg of ammonium carbonate can be applied per mu. The fertilization methods include furrow strip application, hole application and broadcast application. Pay attention to deep or shallow ploughing when sowing to achieve fertilizer effect.

3. Foliar fertilization can also be appropriately carried out in the later stage of sorghum growth, such as spraying potassium dihydrogen phosphate (concentration 0.1%) or sugarcane seeds (concentration 2%) at the beginning of heading and filling to promote early maturity and increase yield.

Methods of topdressing for high yield of sorghum

1. Broadcasting

Generally, broadcasting is used when the amount of fertilizer to be applied is large. Before plowing the land, first spread the fertilizer evenly on the ground and then turn it into the soil. Or after turning the land in autumn, use a leveling rake to make the fertilizer evenly spread on the ground. This is a more labor-saving fertilization method, and it also has a better effect on improving soil fertility.

2. Implementation

Strip application is to pound the fertilizer first and then the manure, with manure and other farm tools as the base material. Strip application is only suitable for low-lying areas and plots with good slurry return, generally applied in autumn, and can also be used to break ridges and sandwich fertilizer in early spring. Ridges and furrows dug too late are prone to water loss and moisture loss, which is not conducive to seedling cultivation and seedling protection. When the quality of fertilizer is poor, dig trenches in the soil while sowing, apply fertilizer evenly in the trenches, and finally cover the soil.

3. Acupuncture

Hole application is a relatively fertilizer-saving method. It is done by applying fertilizer beside the ditch when sowing. It has the same advantages as strip application, but hole application generally requires more labor. To solve this problem, organic fertilizer can be added as base fertilizer when planting the previous crop, or manure can be delivered to the fields in advance before harvest to regulate labor and ensure early sowing of the main crop.