夏大豆极易缺钼,首先是老叶叶脉间失绿出现黄斑,继尔黄斑变为浅棕色,叶缘坏死。严重时植株不开花或花后脱落,造成大幅度减产。实践证明,施用钼肥是防治大豆缺钼症的有效措施。目前常用的钼肥有钼酸铵、钼酸钠和钼渣肥。通常用作种肥和根外追肥: (1)作种肥:取钼酸铵20—30克,先放入瓷盆中,加少量热水溶化(注意不能使用铁容器,以免发生化学反应),然后加入1公斤水配成溶液,均匀喷雾在50公斤的豆种上,边喷边拌种,使药液均匀附着在种子上,随后晾干播种。也可用亩10克钼酸铵加少 Summer soybean susceptible to molybdenum, the first is the old leaves veins appear green macular degeneration, following the macular becomes light brown, leaf margin necrosis. In severe cases, the plants are not flowering or fall off after flower, resulting in a significant reduction in production. Practice has proved that the application of molybdenum fertilizer is an effective measure to control molybdenum deficiency in soybean. The commonly used molybdenum fertilizer is ammonium molybdate, molybdate and molybdenum slag fertilizer. Usually used as fertilizer and root top dressing: (1) for the kind of fertilizer: take 20-30 grams of ammonium molybdate, first into the porcelain basin, add a small amount of hot water to melt (note that iron containers can not be used in order to avoid chemical reactions) , And then add 1 kg of water to form a solution, evenly sprayed on 50 kg of beans, while spray side dressing, the liquid evenly attached to the seeds, and then dried to sow. Also available mu 10 grams of ammonium molybdate less