土壤pH和氧化还原条件对铁的有效性影响很大,高pH土壤往往缺乏有效铁。垫江地属川东平行岭谷区,丘陵钙质紫色土、松沙土、山地石灰岩土种植胡豆常常因缺铁而严重影响产量。胡豆缺铁时,植株生长矮小。根瘤不发达,顶端叶片失绿,并有轻度卷曲。随着缺铁的加重,叶片由淡绿变为灰绿,随后出现棕色斑点。严重缺铁时整个叶片枯黄并出现一团团坏死组织的褐色病斑,甚至整株叶片全部脱落。为了防治胡豆缺 Soil pH and redox conditions have a significant effect on the availability of iron, and high-pH soils often lack available iron. Dianjiang River is located in the eastern part of Sichuan Province, parallel to the Ridge Valley area, hilly calcareous purple soil, pine sandy soil, mountain limestone cultivation of walnuts often due to iron deficiency and seriously affect the yield. When beans are iron-deficient, the plants grow short. Nodules underdeveloped, top leaves greenish, with slight curl. As iron deficiency aggravates, the leaves turn from light green to gray-green, followed by brown spots. Serious iron deficiency, the entire leaves are yellow and brown necrosis of the mass appears necrosis, and even the whole plant leaves all off. In order to control walnut deficiency