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1、缺氮症:植株生长势差,全株黄化,叶片呈淡绿。老叶变黄,干枯或脱落。新叶变小。 (1)发生原因:①土壤氮素含量少;②土壤含水量大,影响了有效氮的转化;③氮肥施用不均等。 (2)防治措施:①避免积水;②多施优质农家肥做基肥,一般亩施堆肥5000公斤。③缺氮时及时补充碳铵、尿素等速效氮肥,一次施肥量不宜过大。一般在芹菜生长期间追施氮肥2-3次,每次可追施尿素10公斤。
1, nitrogen deficiency: plant growth potential poor, whole plant yellow, leaves pale green. Old leaves turn yellow, dry or fall off. New leaves smaller. (1) causes: ① soil nitrogen content less; ② soil moisture, affecting the conversion of available nitrogen; ③ unequal application of nitrogen. (2) Prevention and treatment measures: ① avoid water; ② more than the best manure fertilizer to do basic, general Mushi compost 5000 kg. ③ nitrogen deficiency promptly added ammonium bicarbonate, urea and other available nitrogen, a fertilizer should not be too large. Celery 2-3 times during the growth of topdressing nitrogen, urea can be chased each 10 kg.