Use foliar fertilizer should pay attention to four points

　　 Foliar fertilizer has the characteristics of quick effect, high utilization rate, low dosage, simple application method and obvious yield increase effect, and is widely used in agricultural production. When using the attention points:

　　 Foliar fertilizer selection should be targeted. Crop plants mainly absorb nutrients from the soil , and the content of elements in the soil plays a decisive role in the growth of plants. Therefore, before determining the type of foliar fertilizer, the content of elements in the soil and the acidity and alkalinity of the soil should be determined. Conditionally, the presence of elements in the plant body can be determined , or the leaf surface can be determined according to the external characteristics of the deficiency factor. Type and amount. It is generally believed, in the case of insufficient basal administration may be selected from nitrogen, phosphorus and potassium-based fertilizer; in the basal sufficient administered, may be selected based trace element fertilizer. For example, the falling bud of cotton buds is related to the lack of boron nutrition. Therefore, it is generally applied 2-3 times in the bud stage , and combined with the application of boron fertilizer, the effect of protecting the buds can be achieved.

　　 The solubility of foliar fertilizer is better. Since the fertilizer solution is formulated directly sprayable, foliar must be soluble in the water. Otherwise, the insoluble matter in the foliar fertilizer is sprayed onto the surface of the crop, and it can not only absorb, but sometimes even cause damage to the blade. Thus the fertilizer should be sprayed as a high purity, impurities should be less, generally water-insoluble substance fertilizer should not exceed 5%.

　　 The acidity of the foliar fertilizer should be appropriate. There are different nutrients present in different states of pH. To get the most out of the fertilizer, you must have a suitable range of acidity, generally requiring a pH between 5 and 8 . If the PH value is too high or too low, in addition to the absorption of nutrients , it will also harm the plants.

　　 The concentration of foliar fertilizer should be appropriate. Since the foliar fertilizer market is directly sprayed on the surface of the upper part of the crop, unlike the root application, the buffering effect of the soil is lost. Therefore, we must master the spraying concentration of leaf fertilizer. If the concentration is too low, the amount of elements in contact with the crop is small, and the effect is not obvious; if the concentration is too high, the leaf will cause burns . However, the same fertilizer is applied to different crops at different concentrations, depending on the type of crop. Such as urea: general crop spraying concentration of 1 % -2 %. The spraying concentration on crops such as open vegetables, melons and fruits is generally 0.5 % -1 %. The concentration of spraying on greenhouse vegetables is 1 % -2 %. The seedling spraying concentration of the seedling seedling stage should not be higher than 0.2 %. Trace elements can also be applied foliar spraying, but because of some trace elements in the soil sediment easily lose effectiveness, so agricultural production, the best use of foliar spray, spray concentration is generally 0.3% -0.5 % aqueous solution. Copper, molybdenum concentrations administered should be appropriately reduced.