论文部分内容阅读
作物营养诊断的化学速测(续) (三)钾的测定钾素是植物体内所含有的大量元素之一,在植物体活动部分的灰分中含K_2O可达50％。钾对促进作物的生长发育,加强茎秆纤维韧皮组织和在抗倒伏、抗病害等方面,都有积极作用。在土壤钾素供应不足时,水稻及其它禾本科作物一般表现为生长迟缓,茎部老叶柔弱披散,老叶的尖端和边缘变黄,再变成棕色。叶片上出现棕色斑点并逐渐连成片,整个叶子好象被烧焦的样子。秆子较细弱易于倒伏,穗小产量低。在田间化学诊断中,植株测定一般常用六硝基二苯胺点滴法和亚硝酸钴钠—乙醇法。经过实验室和田间的验证,六硝基二苯胺法比较简单易行,重现性好,能反
Chemical Testing of Crop Nutrition Diagnosis (Cont.) (III) Determination of Potassium Potassium is one of a large number of elements contained in plants. K2O can reach 50% in the ash of plant active parts. Potassium has a positive effect on promoting crop growth and development, strengthening the stalk fiber stalk bark and in lodging, disease resistance and other aspects. Rice and other grass-roots crops generally display sluggish growth when the soil is poorly supplied with potassium, the old leaves are weak and loose, the tips and edges of older leaves turn yellow, and brown. The leaves appear brown spots and gradually into pieces, the whole leaves seem to be charred look. Culms thin and easy to lodging, spike small yield. In the field of chemical diagnosis, the determination of plants commonly used six nitro-diphenylamine drip method and sodium nitrite cobalt-ethanol method. After laboratory and field validation, hexanitro diphenylamine method is relatively simple, reproducible, and can be reversed