Effects of Low pH on Uptake Rate of Inorganic Nitrogen by Different Plant Seedlings

摘要

Most experimental plants absorbed NO3- -N faster at pH 4.0 than at pH 6.0 and absorbed NH4+-N slower, but few experimental plants showed different tendency. The exceptions of NO3- uptake were probably due to excessive nitrate outflow of some maize and wheat varieties ( Suyu 19, Zhendan 958 and Yangmai12) at low pH. Some other experimental plants ( Huaidao 8, Nongda108 and Yangmai12) even showed no obvious NH4+ toxic symptoms at pH 4.0. The effects of low pH on uptake rate of NH4+ -N and NO3- -N varied with plant species, varieties, and the difference increased with the age of the seedlings.