ALLEVIATION OF INJURIOUS EFFECTS OF SULPHUR DIOXIDE ON SOYBEAN BY MODIFYING NPK NUTRIENTS

摘要

Soybean (Glycine max L. JS-72-44) plants were grown at three mineral nutrient levels: NPK recommended dose, double NPK recommended dose and without nutrient application. The effects of sulphur dioxide and fertiliser singly as well as in combination on soybean plants were studied by exposing 30-day-old plants to 0.15 p.p.m. SO, for 4 h day(-1), 5 days week(-1) for 6 weeks. Photosynthetic pigments, ascorbic acid and protein contents, biomass and productivity were quantified prior to fumigation and at 15 day intervals until the plants were 75 days of age. Following SO2 exposure, all parameters decreased, the maximum reduction being in plants grown without nutrient application. The study suggests that plants receiving recommended amounts of fertiliser are not as severely injured by SO2 as an unfertilised crop, but an increase in fertilisation above the recommended level did not provide further protection.