加气灌溉对温室葡萄生长及不同形态氮素吸收利用影响

摘要

为探讨地下穴贮滴灌条件下根际注气对“红地球”葡萄幼苗生长及不同形态氮素吸收代谢的影响,以2年生“红地球”葡萄幼苗为试验材料,通过地下穴贮滴灌注气技术和15N示踪技术研究根际注气条件下葡萄对铵态氮(NH4+-N)和硝态氮(NO3--N)吸收、分配和利用的影响.研究结果表明,地下穴贮滴灌根际注气可促进葡萄新梢增长,茎粗增加,显著提高葡萄新梢、细根等植株干物质量的积累.在同一灌水周期内,地下穴贮滴灌根际注气可提高叶片叶绿素、净光合速率,延缓植株胁迫,但对植株叶片瞬时水分利用效率具有负面影响.通过氮同位素示踪标记表明,地下穴贮滴灌条件下无论是否注气,葡萄新生部位对硝态氮的征调能力、吸收利用效率均显著高于铵态氮;与不注气相比,注气处理可显著促进新生部位对硝态氮的吸收,抑制铵态氮的吸收利用.地下穴贮滴灌根际注气可促进葡萄的生长,提高叶片光合效率,15N示踪表明根际注气并未影响葡萄根系对硝态氮的偏好,在地下穴贮滴灌注气条件下氮素形态宜选择硝态氮作为氮肥来源.%In order to investigate the effect of rhizosphere aeration on NH4+-N and NO3--N absorption and metabolism of red globe grape seedlings,the experiment was done by taking 2-year old red globe grape seedling as test material,through subsurface drip irrigation (SDI) with tanks technique and 15N tracer technique to study effect of the rhizosphere aeration treatment on plant growth and NH4+-N and NO3--N absorption,distribution and utilization.The results showed that rhizosphere aeration under SDI with tanks could promote the growth of new shoots,increase the stem diameter,and especially significantly increase the dry matter accumulation of new shoots and fine roots.In the same irrigation period,rhizosphere aeration under SDI with tanks increased the SPAD value and net photosynthetic rate of the leaves,but it had negative effects on the instantaneous water use efficiency of the plant leaves.The nitrogen isotope tracer results showed that grape new organs on the NO3--N Ritchie ability,absorption and utilization efficiency were significantly higher than that of NH4+-N under aeration treatment and without aeration treatment,and the results showed that rhizosphere aeration under SDI with tanks did not affect the nitrate preference of grape plants.The results also showed that gas injection treatment can significantly promote the absorption of nitrate uptake and utilization of new organs,inhibition of ammonium nitrogen,which suggested that nitrate nitrogen should be selected as nitrogen source under the condition of rhizosphere aeration under SDI with tanks.