What issues should be noted when topdressing eggplants in summer?
1. Appropriate amount. Eggplants have the highest demand for nitrogen fertilizer, but in high-temperature seasons, each application of urea per mu should generally be controlled within 30 kg, because in high-temperature seasons, urea transforms relatively quickly after being applied to the soil, and after the plants have met their needs, the excess portion will be lost. Especially in sandy soil, the proportion lost will be even greater...
1. Appropriate amount. Eggplants have the highest demand for nitrogen fertilizer, but in high-temperature seasons, each application of urea per mu should generally be controlled within 30 kg, because in high-temperature seasons, urea transforms relatively quickly after being applied to the soil, and after the plants have met their needs, the excess portion will be lost. Especially in sandy soil, the proportion lost will be even greater. For ammonium bicarbonate, the appropriate application rate per mu each time is no more than 40 kg. If the application rate is too large, besides causing nutrient loss, it will also cause ammonia damage to eggplant leaves and fruit.
2. Appropriate method. Vegetable growers have become accustomed to applying chemical fertilizers with irrigation water, but this method should not be used in high-temperature summer seasons. Because the temperature is relatively high, when chemical fertilizers are applied with irrigation water, a large amount of ammonia volatilizes and reduces fertilizer efficiency. Ammonium bicarbonate in particular is more likely to cause ammonia poisoning in eggplants. Applying by furrow or in holes gives the best results. After topdressing, the soil cover thickness should be no less than 5 cm to reduce volatilization of the effective components of the chemical fertilizer.
3. Reasonable combination. Although eggplants have the greatest demand for nitrogen fertilizer, phosphorus and potassium fertilizers are also indispensable, and nitrogen fertilizer cannot be applied at every topdressing. During the full fruiting period, it is best to apply a three-element compound fertilizer 2 times, with a total of no less than 40 kg per mu over the 2 applications, to meet the needs of eggplant growth and fruiting.