植物营养与肥料学报2010，16(5)：1114-1119 Plant Nutrition and Fertilizer Science
红壤施氮对玉米水分胁迫指数的影响
陈家宙，林丽蓉，吕国安，王双
（华中农业大学，农业部业热带农业资源与环境重点开放实验室，湖北武汉430070）
摘要：为了探讨干旱条件下红壤水氮管理措施，在田间遮用小区设置连续0～32d不灌水的7个干旱水平和N0、 140、280kg/hm3个施氮水平的试验，研究了氮肥对夏玉米作物水分胁迫指数（Cropwaterstressindex，CWSI）的影响。结果表明，CWSI可以指红填干旱时玉米水分胁迫状况，但增施氮肥后，CWSI与产的关系发生了偏移。在 CWSI低于0.20时，增施氮肥对CWSI无明显影响：在CWSI大于0.20时，增施氮肥使玉米产量下降，高量氮肥还
使CWSI上升，作物受加制。说明增施氮肥对CWSI的影响因玉米干早胁迫程度和施氮量而异。关键词：红壤；氮肥；作物水分胁迫指数；夏玉米
中图分类号：S513.062
文献标识码：A
文章编号：1008-505X(2010)05-1114-06
Effectsof nitrogenfertilizationoncropwaterstress indexof
summer maize in red soil
CHEN Jia-zhou, LIN Li-rong, LO Guo-an, WANC Shuang
(Key Laboratory of Subtropical Agriculture and Enrironment, Ministry of Agriculture/
Huazhong Agricultural University, Wuhan 430070,China)
Abstract: Available soil water and N fertility are the primary factors limiting dryland crop yield in red soil areas of south China, where N nutrient is usually deficient and seasonal drought occurs frequently during summer and au tumn. For the strategy of soil water and N fertilizer management, we investigated the effects of nitrogen fertilization on the crop water stress index ( CWSI) in summer maize, The experiments were carried out in the waterproof field plots with sufficient irrigation before and after the soil drying interval of 0, 7, 12, 17, 22, 27 and 32 days in the maize growth period from 30 to 62 days after planting. Nitrogen fertilizer was broadcast as urea st N 0, 140, and 28O kg/ha for each drought treatment.The results show that CWSI is an indicator of maize crop water stress status during the soil drying course. However, the relationship between CwSI and crop yield are changed by increasing the slope of regression equation under the application of N fertilizer. Under slight and moderate soil droughts, N fertilization has less influence on CWSI, while under severe soil drought, the crop yield is decreased under N ferti-lization and CWSI is increased under high amount N fertilizer, which indicates crop water stress is aggravated by in-creasing levels of N fertility. The results suggest that the effects of N fertilization on CWSI vary as the fluctuations of soil water stress and amount of N fertilizer.
Key words:red soil; nitrogen fertilizer; crop water stress index; summer maize
我国南方红壤丘陵岗地是重要的农业资源，然而红壤农田普遍缺氮，增施氮肥成为提高红壤作物产量的重要措施。一般认为，氮肥应该施用在土壤有效水充足的地块0)，红壤地区年降水充沛，但夏秋之交也常常发生季节性干旱。如夏玉米在生长过程中有较长的时间会受到水分胁迫，有的年份因干
收稿日期：2009-11-14
接受日期：2010-02-01
旱减产严重。红壤丘岗旱地一般无灌溉设施，因此根据红壤自然水分状况合理施用氮肥，对增强作物御旱能力和提高产量具有重要意义。
作物在受到水分胁迫的时候，其生理过程和外部形态都会发生变化。如叶片气孔导度降低、叶水势降低、光合速率降低、叶片伸长和茎杆增粗速率减慢等，
基金项目：教育部科学技术研究重点项目（No.108093)；国家自然科学基金项目（No.40871139）资助。
作者简介：陈家宙（1968—），男，翻北监利人，教授，主要从事土壤水分研究。Tel：027-87283960，E-mail：jechen@mail.hzau.edu.cn 万方数据