| 摘要: |
| 由于降雨时空分布不均,我国玉米主产区在播种期经常遭遇季节性干旱,严重限制玉米播种、萌发和苗期生长,与之相适应的灌溉措施有待于完善。本研究以郑单958为材料,在控制条件下布置盆栽试验,研究玉米播种期水分胁迫以及播后补水对玉米出苗和根系生长的影响,明确补充灌溉的缓解作用,并确定在不同土壤墒情下播种后的适宜补灌量。本研究设定7个处理:正常供水,轻度水分胁迫下设定湿土点种、播后补灌15.0 mm和22.5 mm 蒙头水,中度水分胁迫下设定湿土点种、播后补灌15.0 mm和22.5 mm蒙头水。结果表明:1)随着土壤墒情变差,玉米出苗率下降,叶面积和生物量显著减小,根冠比增大,根系的生长受到阻碍。2)播种后浇灌蒙头水是有效缓解土壤干旱带来不利影响的农艺措施之一,显著提高玉米出苗率,缩短出苗时间,促进根系生长,根条数、根层数、总根长、根表面积和根体积显著增加,与不补水相比,补灌蒙头水处理的根长增加13.5%~146.6%,根表面积提高22.9%~166.8%,根体积增加32.9%~117.6%。3)补灌蒙头水对水分胁迫越重的处理效果越显著,且补灌量越大,缓解程度越高。其中,播种时土壤墒情为田间持水量的50%~65%时,适宜在播种后补灌22.5 mm的蒙头水缓解旱情,促进幼苗根系的生长。 |
| 关键词: 玉米 根系 生长 播种期 干旱 蒙头水 |
| DOI：10.11841/j.issn.1007-4333.2015.06.03 |
| 投稿时间：2014-12-22 |
| 基金项目:中央高校基本科研业务费专项资金(2014JD056) |
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| Effects of drought and irrigation after sowing on maize seedling growth |
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XIE Qian, CHEN Guan-ying, TAO Hong-bin, ZHANG Ping, ZHOU Nan, Ren Wei, WANG Pu
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| (College of Agronomy and Biotechnology/Key Laboratory of Farming System of Ministry of Agriculture, China Agricultural University, Beijing 100193, China) |
| Abstract: |
| Seasonal drought frequently occurred at maize sowing stage due to unevenly distributed precipitation in China,which limited seed emergence and seedling growth severely.Irrigation after sowing played an important role on maize seedling developments,and the corresponding irrigation amounts shall be determined to ensure plant establishment.Therefore,a pot experiment was conducted under greenhouse condition to clarify a proper irrigation amount after sowing under drought stress.Seven treatments were designed:sufficient water supply,light drought stress with 0,15,22.5 mm water after sowing and medium drought stress with 0,15,22.5 mm water after sowing.The results showed: root development and growth were inhibited as soil moisture decreased.Simultaneously,emergence rate,leaf area,shoot and root dry matter accumulation decreased with an increase of root-shoot ratio due to drought stress;Supplemental irrigation after sowing is one of the effectively agronomic measures to release drought stress,which significantly increased emergence rate,shortened emergence time and promoted root growth.Compared with no irrigation after sowing,root number,root layer number,root length,root surface area and root volume were all significant increased after irrigation;Irrigation after sowing had more significant effect under medium drought stress than under light drought stress.In addition,higher amount of irrigation water led to stronger recover effect.Irrigating 22.5 mm water after sowing relieved drought stress and promoted root establishment when soil moisture was between 50%-65% of the field capacity. |
| Key words: maize root growth sowing stage drought irrigation after sowing |
