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农作物所需营养元素很多,土壤含有养分种类也很多,因此可测项目就很多。但目前最突出的是氮、磷、钾三要素,以及与其相关的土壤水分和质地等。本着急用必测的原则,仅介绍有效氮、磷、钾的通用简易测定方法。 (一)土镶有效养分浸出液的制备 1.浸提原理采用分别测定法测定土壤有效养分,难以进行速测。山西省闻喜县和山西农学院以0.7N(当量浓度)碳酸氢钠(NaHCO_3)作为测定土壤中硝态氮、铵态氮、有效磷和有效钾的通用提取剂,便克服了分别测定法不能速测的缺点。该县经过对10％醋酸钠(NaC_2H_3O_2·3H_2O)、10％氯化钠(NaCl)、蒸馏水、0.5N硫酸(H_2SO_4)和0.5N碳酸氢钠等五种浸提剂进行反复对比试验,选出0.7N碳酸氢钠作为通用提取剂,不仅
Many crops require nutrients, the soil contains many types of nutrients, so a lot of measurable items. But at present, the three most prominent elements of nitrogen, phosphorus and potassium, as well as their associated soil moisture and texture. In the urgent need to test the principle of effective nitrogen, phosphorus, potassium only simple and easy to determine the general method. (A) Preparation of soil effective nutrient leaching solution Preparation 1. Leaching Principle Determination of soil available nutrients were measured separately, it is difficult to carry out rapid measurement. Shanxi Province Wenxi County and Shanxi Agricultural College to 0.7N (equivalent concentration) of sodium bicarbonate (NaHCO_3) as the soil nitrate nitrogen, ammonium nitrogen, available phosphorus and available potassium general extract, will overcome the separate assay Can not be measured shortcomings. The county after repeated comparison experiments of five kinds of extractants such as 10% sodium acetate (NaC_2H_3O_2.3H_2O), 10% sodium chloride (NaCl), distilled water, 0.5N sulfuric acid (H_2SO_4) and 0.5N sodium bicarbonate, 0.7N sodium bicarbonate as universal extractant, not only