摘要
在pH4.0、6.0水培条件下,分别供应NH_4^+-N和NO_3^--N2种不同形态的氮源,研究玉米根系对氮素的吸收与溶液中H^+浓度变化的关系以及不同pH条件下不同氮素形态对玉米生长的影响。结果表明:①在介质中有NH_4^+-N存在时,玉米对NH_4^+的吸收会导致pH值下降,且无论起始pH值的高低,最终达到的最低pH值相当接近;②起始pH值为4.0和6.0时,玉米每吸收1个NH_4^+后释放大约0.8～0.9个H^+;③起始pH值为4.0时,玉米根系每吸收1个NO_3^-大约消耗1.22个H^+,但在起始pH值为6.0时,吸收1个NO_3^-仅需消耗0.024个H^+;④低pH值能促进NO_3^--N的吸收,高pH值更有利于NH_4^+-N的吸收;⑤尽管NH_4^+的净吸收速率大于NO_3^-,但其对生物量的积累作用小于后者。
The relationship between N uptake by young corn (Zea Mays L. ) and the H+concentration changes in nutrient solution was investigated by supplying two different N sources (NH4+-N, NO3--N) at two different primal pH levels (pH 4. 0, 6. 0). The effects of N source and pH levels on the growth of young cornwere also studied at the same time. The results were as follows: ① At the presence of NH+-N, the solution's pH were reduced and the lowest pH levels were all similar in different initial pH situations; ② At both initial pH levels the uptake of one NH4+was accompanied by the release of about 0. 8 to 0. 9 H+;③ When absorbing one NOr . about 1. 22 H+ were consumed at the initial pH4. 0, whereas only about 0. 024 H+ were needed at pH 6. 0. which suggested that the NO3- /H+ ratio during cotrans-port may differ a lot at different initial pH levels ; ④ Low pH in the solution promoted the uptake of NO3-, while high pH increased the uptake of NH4+ ;⑤ Though the net uptake rate of NH,+ was greater than that of NO3- the later contributed more to the biomass accumulation.
出处
《扬州大学学报（农业与生命科学版）》
CAS
CSCD
2003年第3期46-50,共5页
Journal of Yangzhou University：Agricultural and Life Science Edition
基金
国家自然科学基金(30270783)
