Different fertilization depth has different effect

The growth of crops in the soil mainly depends on the root system to absorb nutrients, and the degree of root development of different crops is different, that is, the depth of root growth is different, even if it is the same crop, in different growth stages, the depth of root distribution in the soil layer is also different.

Reasonable fertilization should apply most of the fertilizer in the dense layer of the root system and in the part with the strongest root activity, which is beneficial to the absorption of nutrients by crops. The roots of wheat, rice and other food crops are mainly distributed in the 0-20 cm soil layer, while the roots of citrus, apple and other fruit trees are mainly distributed in about 40 cm.

Therefore, the same fertilizer should be applied to different crops at different depths. In the early stage, the root system of crops develops slowly and is mostly distributed in the surface layer, so the application of seed fertilizer should be shallower; but when the crop grows to the middle stage, the root system is tied down, the soil nutrient is insufficient, and the topdressing depth should be considered. The method of ditch application or hole application should be adopted to make the fertilization depth adapt to the root distribution as far as possible. In order to meet the nutrient demand of crops during the whole growth period, sufficient base fertilizer should be applied at the main levels of root distribution (such as wheat and rice at 0-20 cm) before planting crops, so as to meet the fertilizer needs of crops at different development stages. Yang Dongwen