The application method and precautions of ammonium sulfate

Ammonium sulfate [(NH4)2SO4], also known as ammonium sulfate,

is the earliest nitrogen fertilizer produced and used at home and abroad. It is usually regarded as a standard nitrogen fertilizer with a nitrogen content between 20% and 21%. Pure ammonium sulfate is a white crystal, the by-product is yellowish or gray, has low hygroscopicity, and is not easy to agglomerate, so it is easier to store and more soluble in water. Ammonium sulfate is a physiological acid quick-acting nitrogen fertilizer, which is generally suitable for wheat, corn, rice, cotton, sweet potato, hemp, fruit trees, vegetables and other crops. For soils, ammonium sulfate works best in neutral and alkaline soils, but not in acidic soils.

The main methods of application of ammonium sulfate are as follows:

1. As base fertilizer. When ammonium sulfate is used as base fertilizer, it should be deeply covered with soil to facilitate crop absorption.

Second, for top dressing. This is the most suitable method of application. Determine the amount of ammonium sulfate topdressing according to different soil types. For soils with poor water and fertilizer retention performance, topdressing should be applied in stages, and the dosage should not be too much each time; The amount of soil moisture also has a greater impact on fertilizer efficiency, especially in dry land. When applying ammonium sulfate, we must pay attention to watering in time. As for top dressing in paddy fields, it should be drained and dried first, and attention should be paid to the simultaneous application of ploughing and harrowing. In addition, there are obvious differences in the application of ammonium sulfate to different crops. For example, when it is used for fruit trees, it can be applied in furrows, rings or holes.

Third, it is more suitable for seed fertilizer. Because ammonium sulfate has no adverse effect on seed germination.

The following problems should be paid attention to when applying ammonium sulfate: (1) Ammonium sulfate fertilizer should not be applied in contact or mixed with other alkaline fertilizers or alkaline substances to avoid reducing fertilizer efficiency. (2) It is not advisable to apply ammonium sulfate on the same farmland for a long time, otherwise the soil will become sour and cause hardening. If it is really necessary to apply, some lime or organic fertilizer can be applied in an appropriate amount. However, it must be noted that ammonium sulfate and lime cannot be mixed to prevent the decomposition of ammonium sulfate and cause nitrogen loss. Generally, the combined application of the two should be separated by 3 to 5 days. (3) Ammonium sulfate is not suitable for application on acidic soil.