Trace Element Fertilizers

Trace elements include six elements of zinc, boron, molybdenum, manganese, iron, and copper. It is all necessary for crop growth and development. It is only because the crop needs very little of these elements, so it is called trace elements. In the 50s and 60s of the 20th century, organic fertilizers were mainly used, supplemented by chemical fertilizers, the lack of trace elements was not outstanding. With the increase in the application of a large number of elements, the yield of crops was greatly increased, and the proportion of organic fertilizer input was added. As a result, the lack of trace elements in the soil has also increased. However, there is a difference in the demand of trace elements between different soil textures and different crops, and the abundance of the trace elements should be determined according to the effective content of trace elements in the soil, so that the deficiency of supplement elements can be achieved. Under normal circumstances, when the effective content of trace elements in the soil is low, it is easy to produce deficiency factors, and the trace elements that are supplied can achieve the effect of increasing production (Table 1).
Table 1 Effective content of trace elements in soil Abundance of trace elements Trace elements are very low in grading (Mg/kg) (mg/kg) (mg/kg) (mg/kg) (Zn/Zn) < 0.50 .5 to 1.01.1 to 2.02.1 to 4.0> 4.0 Boron (B) <0.250.25 to 0.50.51 to 1.01.1 to 2.0> 2.0 Molybdenum (Mo) <0.10.1 to 0.150.16 to 0.20.21 -0.3> 0.3 Manganese (Mn) <55.0 to 10.010.1 to 2020.1 to 30.0> 30 Iron (Fe) <2.52.5 to 4.54.5 to 1010 to 20> 20 Copper (Cu) <0.10.1 to 0.20.2 ~1.01.1 to 2.0>2.0

Micronutrients are mostly components or activators of enzymes, coenzymes in crops, and they play an important role in the synthesis, photosynthesis or metabolic processes of chlorophyll and proteins, as well as in the absorption and utilization of nutrients such as nitrogen, phosphorus, and potassium. Promote and regulate effects. Although the demand for trace elements in crops is small, the application of corresponding trace fertilizers to soils that lack nutrients or potential nutrients can greatly increase the yield of crops and improve the quality of agricultural products. Tests have shown that molybdenum fertilizers applied to bean crops, boron fertilizers to fruit crops such as sugar beet, rapeseed, cotton and apple, citrus, and bayberry, zinc fertilizer to rice, corn, fruit trees, vegetables, manganese fertilizer to wheat, tobacco, and hemp crops Copper fertilizer has an increasing effect on wheat, rice, and other crops, generally increasing production by about 10%. In soils that are severely nutrient-depleted, application of the corresponding micronutrients can even increase yields. Applying micronutrients to soils deficient in micronutrients has the effect of improving product quality in addition to increasing yield. In addition, the application of trace fertilizer can also increase the crop's resistance to diseases, low temperature, high temperature and drought. However, excessive trace element content in soil or excessive application of trace fertilizer may severely reduce crop yield and quality.