不同氮素形态供应对玉米幼苗生物量和氮素累积的影响

Effect of Different N Forms on the Dry Weight and N Accumulation of Maize Seedlings

采用营养液培养方法,研究不同形态氮素供应对玉米幼苗生物量和氮素累积的影响。结果表明,登海605和鲁单981地上部植株干重均表现为硝酸钙>硝酸铵>尿素>硫酸铵处理。两个品种根系干重在硝酸钙、硝酸铵和尿素处理下无显著差异,均高于硫酸铵处理下的根系干重。两个品种地上部植株氮浓度和叶片SPAD值均表现为硝酸钙<硝酸铵<尿素<硫酸铵处理。登海605地上部氮素累积量在硝酸钙、硝酸铵、尿素和硫酸铵处理下呈下降趋势;鲁单981地上部氮累积量在不同氮素供应条件下无显著差异。与其他氮素形态相比,硝酸钙供应条件下氮素生理效率最高,最有利于促进玉米幼苗干物质累积,但造成地上部植株氮浓度的稀释效应。

A solution culture experiment with two maize hybrid lines was conducted to study the effects of dif-ferent N forms on the dry weight and N accumulation of maize seedlings. The results showed that the shoot dryweight of the two maize hybrid lines was in the order, Ca（NO3）2NH4NO3Urea-N（NH4）2SO4. The root dry weight ofthe two maize hybrid lines was significantly lower with the treatment of（NH4）2SO4supply compared with the otherthree N forms, where the root dry weight was not significantly different. The shoot N concentration and leaf SPADvalues of the two maize hybrid lines were in the order, Ca（NO3）2NH4NO3Urea-N（NH4）2SO4. The shoot N accumu-lation of Denghai605 tended to decrease with the treatment orders of Ca（NO3）2, NH4NO3, Urea- N and（NH4）2SO4while that of Ludan981 was not affected by different N forms.These results suggested that compared with the otherthree N forms, the treatment of NO3-N supply signficantly incresed the internal N efficiency and further improvedthe dry weight accumulation, but resulted in N dilution effect of maize seedlings.