四川南充地区柑桔主要分布在钙质紫色土上,土壤pH值在8.0以上,从而降低了土壤中铁的有效性。缺铁黄化已成为本地区柑桔生产中的严重问题,据调查,南充、西充等县20%左右的柑桔面积发生黄化,莲安县更为严重,全地区每年损失柑桔产量约450万公斤,更有甚者,因无法根治此症而砍树毁园。多数研究结果表明,叶面喷施硫酸亚铁,仅能获 Citrus in Nanchong, Sichuan Province is mainly distributed in calcareous purple soil, with soil pH above 8.0, reducing the availability of iron in the soil. Iron deficiency yellowing has become a serious problem in the citrus production in the region. According to the survey, about 20% of the citrus areas in Nanchong and Xichong County are yellowing and Lian’an County is even more serious. The annual output of citrus in the whole region is about 4.5 million kilograms, what is more, because they can not cure this disease and cut tree destruction Park. Most studies show that foliar application of ferrous sulfate can only be obtained