灌溉模式和氮肥用量对水稻分蘖期生长特征的影响

Effect of Irrigation and Nitrogen Application on Growth of Two Rice Cultivars at the Tillering Stage

【目的】研究灌溉模式和氮肥用量对水稻分蘖期主要生长指标性状的影响,寻找节水减肥、水肥高效的稻田水肥管理模式。【方法】以适宜豫北沿黄稻区种植的早熟晚粳稻"五粳04136"和杂交早稻"Y两优3218"为供试材料,采用田间试验方法,试验主处理设置100、200、300 kg/hm23个氮肥用量(N100、N200、N300),副处理设置干湿交替灌溉(AWD)、浅水淹灌即长期淹水(SW)、湿润灌溉(HI)3种灌溉模式,于水稻最大分蘖期选取每小区长势一致的植株及相应土壤样品测定水稻地上部和土壤养分等相关指标。【结果】水稻分蘖期生物量、分蘖数、株高、耕层土壤铵态氮量、硝态氮量、根系GS活性及植株叶、叶鞘、根系含氮量整体受氮肥用量的影响均大于受灌溉方式的影响;分蘖期水稻根系伤流液强度受氮肥用量和灌溉模式的影响均较明显;而水稻分蘖期叶龄受氮肥用量和灌溉模式的影响都较小,尚未表现出显著差异。【结论】灌溉模式和氮肥用量对水稻分蘖期各生长指标的影响程度不一,二者影响各指标的内在机制有待进一步研究。

【Objective】Physiological development of plants is regulated by soil water and nutrients and the aim of this paper is to study how irrigation and nitrogen application combine to affect growth of two rice cultivars at tillering stages with view to provide a guidance to their sustainable production.【Method】The experiment was conducted in pots and the two cultivars studied were the early-mature japonica rice Wujing 04136 and the early-mature hybrid Y Liangyou 3218. For each cultivar, we considered three nitrogen fertilizer applications:100 kg/hm^2(N100), 200 kg/hm^2(N200) and 300 kg/hm^2(N300); and three irrigations schedules: Alternate wetting-drying irrigation(AWD), shallow-water flood irrigation(SW), and humid irrigation(HI). When the tillering of the rice reached maxima, plant traits and soil properties in each pot were measured.【Result】Compared to irrigation, nitrogen fertilizer application had more significant impact on biomass, tiller number, plant height, soil ammonium and nitrate content, activity of root, plant leaf, sheath and nitrogen concentration in roots. Both nitrogen fertilizer application and irrigation had noticeable effects on sap flow in roots, but insignificant impact on leaf aging.【Conclusion】The influence of irrigation and nitrogen on growth of the two rice cultivars during the tillering stage varies and the underlying mechanisms require further investigation.