Crop damage identification and prevention
Identification In general, the characteristics of crop damage, mainly as follows: 1, dehydration. Excessive application of fertilizer, or soil over drought, caused by the local concentration of soil after fertilization is too high, resulting in crop water loss and showed a state of wilt. 2, burns. At high temperatures in the hot sun, the use of highly volatile fertilizers (such as ammonium bicarbonate, etc.) causes burns (burning) of the leaves or young tissues of the crop. 3, poisoning. The content of "biuret" in urea is more than 20%, or the free acid content in superphosphate is higher than 5%. After applying it into the soil, the roots of the crop are poisoned and rotted; a large amount of organic fertilizer without decomposition is used because of its decomposition. Fever and release of harmful gases such as methane, causing poisoning of crop seeds or roots. Prevention 1, choose to apply standardized fertilizer. 2, dressing the right amount. Ammonium bicarbonate should not exceed 25 kilograms per acre, and pay attention to deep application, after the application of soil or cultivator; urea per application amount is controlled below 10 kg; application of foliar fertilizer, the appropriate concentration of various trace elements, generally Between 0.01% and 0.1%, a large number of elements (such as nitrogen, etc.) are between 0.3% and 1.5%, and should be sprayed at the right concentration and in proper concentration. 3, seed fertilizer isolation. When sowing a dry crop, it is advisable to apply the fertilizer first and mix it in the soil layer to avoid direct contact with the seeds. 4, reasonable water supply. When the dryland soil is too dry, it is advisable to fertilize it appropriately or fertilize it with water. When paddy fields use volatile fertilizers, it is advisable to keep the appropriate shallow water layer in the field and apply the cultivator to the paddy field immediately after application. 5, fertilizer uniform application. When spreading chemical fertilizers, pay attention to evenness. If necessary, mix suitable amount of clay powder or fine sand. 6, timely fertilization. It is generally advisable to control the dry dew after sunrise, or fertilize in the afternoon, and avoid doing it in the air during the hot sun. In addition, we must adhere to the application of organic fertilizers that have been tampered with. In the process of topdressing chemical fertilizers, we must pay attention to placing unapplied chemical fertilizers in the downwind position to prevent the volatile gases from being blown into the crops by the wind, so as to avoid injury. If the crops are inadvertently caused by the above-mentioned fertilizers, appropriate measures such as appropriate irrigation and drainage, or removal of the affected parts should be promptly adopted to control their development and promote the restoration of normality.