摘要
在轻简化施肥背景下,为减少渍害损失,解决长江流域冬油菜产区生产面临的重要问题,开展氮肥施用对油菜渍害的缓解作用研究。设置三因素田间试验,分别为不同氮肥用量(0、60、120、180、240和300 kg N/hm^2)、氮肥类型(油菜专用控释尿素和普通尿素)和水分处理(苗期渍水和正常排水),测定各处理产量和氮肥农学利用率,明确苗期渍水对不同氮素供应水平油菜的影响,并比较油菜专用控释尿素一次性施用和普通尿素分次施用下油菜对苗期渍水的响应。结果表明,直播冬油菜产量随氮肥施用量增加而提高,至240 kg N/hm^2时不再增加。油菜专用控释尿素一次性施用,在氮肥用量为60~180 kg N/hm^2时产量高于普通尿素分次施用;在氮肥用量为240~300 kg N/hm^2时,两种氮肥类型产量基本相当。氮肥施用通过增加收获密度、单株角果数和每角粒数提高产量。苗期渍水导致直播冬油菜产量损失1.1%~41.9%,随氮肥用量增加,渍水引起的产量损失率呈先增加后降低趋势。0~60 kg N/hm^2处理时,渍水使收获密度显著降低(降幅达29.4%~45.0%),单株角果数增加;施氮量为120~180 kg N/hm^2时,渍水导致收获密度和单株角果数分别降低19.5%~33.7%和1.4%~17.7%;施氮高于180 kg N/hm^2时,收获密度和单株角果数降幅减小(降幅分别为5%~30.9%和3.6%~9.5%)。普通尿素分次施用和油菜专用控释尿素一次性施用,分别在施氮量为120和180 kg N/hm^2时产量损失率最高,分别达29.8%和41.9%。相同氮肥用量下油菜专用控释尿素一次性施用的产量损失率大于普通尿素分次施用。渍水显著降低氮肥农学利用率,降幅为8.4%~51.9%,施氮充足(240~300 kg N/hm^2)时氮肥农学利用率降幅低于氮素用量较低处理(120~180 kg N/hm^2),油菜专用控释尿素一次施用处理的农学利用率平均降幅(36.5%)高于普通尿素分次施用(17.3%)。综上可知,苗期渍水时,油菜专用控释尿素一次施用,会加重油菜受渍影响;土壤氮素供应能力较低时,渍害逆境解除后,适量追施速效氮肥可有效缓解产量损失,实现油菜稳产。
It is important to reduce oilseed rape(Brassica napus L.) yield loss subjected to waterlogging in the Yangtze River Basin under simplified fertilization background. How to alleviate the waterlogging loss by way of nitrogen(N) fertilizer application was studied. Three factors, including different N rates(0, 60, 120, 180, 240 and 300 kg N/hm^2), N sources(controlled release urea and common urea) and water managements(waterlogging at seedling stage and normal drainage), were set in a field experiment. Yield and agronomy efficiency of oilseed rape at varying N rates were investigated, to identify effects of waterlogging at seedling on oilseed rape with different N fertilizer rates and their responses with controlled release urea one-off application(CRU1) and common urea split application(U4), respectively. Results showed that oilseed rape yield increased with the increase rate of N fertilizer application, plateaued at 240 kg N/hm^2. Yield of CRU1 were higher than that of U4 at 60-180 kg N/hm^2, but similar at 240-300 kg N/hm^2. N fertilizer application increased plant population density at harvest(PPDh), pod number per plant and seed number per plant, which resulted greater oilseed rape yield. Waterlogging at seedling stage decreased oilseed rape yield by 1.1%-41.9%. The yield loss increased as N rates added, then decreased as CRU1 and U4 added to 120 and 180 kg N/hm^2, respectively. The largest yield loss of CRU1 and U4 were 29.8% and 41.9%, respectively.In case of waterlogging, PPDh decreased significantly(with decrease of 29.4-45.0%), but pod number per plant increased at the N rate of 0-60 kg N/hm^2. When N rate was at 120-180 kg N/hm^2, both PPDh and pod number per plant decreased by 19.5-33.7% and 1.4-17.7% once subjected to waterlogging, respectively. While as N rate was more than180 kg N/hm^2, both the PPDh and pod number per plant decrease was reduced(with the decrease of 5-30.9% and 3.6-9.5%, respectively). Yield losses induced by waterlogging of CRU1 were larger than that of U4 at same N rate. Waterlogging at seedling stage decreased N agronomy efficiency by 8.4-51.9%. Generally, the agronomy efficiency decrease with sufficient N supply(240-300 kg N/hm^2) was less than that of insufficient N supply treatments(120-180 kg N/hm^2), and CRU1(with the average agronomy efficiency decrease of 36.5%) had greater agronomy efficiency decrease relative to U4 treatments(with the average agronomy efficiency decrease of 17.3%)). In a word, waterlogging at seedling stage had greater impact on direct-sown winter oilseed rape yield with CRU1 application relative to U4. In the area with low indigenous N supply capacity, available N topdressing with appropriate rate after waterlogging can alleviate the yield loss and ensure the high production of oilseed rape.
作者
刘秋霞
任涛
韩上
李小坤
丛日环
武际
鲁剑巍
LIU Qiu-xia;REN Tao;HAN Shang;LI Xiao-kun;CONG Ri-huan;WU Ji;LU Jian-wei(Microelement Research Center,Huazhong Agricultural University,Key Laboratory of Arable Land Conservation(Middle and Lower Reaches of Yangtze River),Ministry of Agriculture and Rural Affairs,Wuhan 430070,China;Institute of Soil and Fertilizer,Anhui Academy of Agricultural Sciences,Hefei 230000,China)
出处
《中国油料作物学报》
CAS
CSCD
北大核心
2020年第4期594-602,共9页
Chinese Journal of Oil Crop Sciences
基金
国家自然科学基金(31471941)
国家重点研发计划项目(2018YFD0200900)
国家油菜产业技术体系建设专项(CARS-12)。
关键词
直播冬油菜
氮肥
渍水
产量构成
农学利用率
direct-sown winter oilseed rape
nitrogen fertilizer
waterlogging
yield components
agronomy efficiency
作者简介
刘秋霞(1989-),女,湖北咸宁人,博士研究生,研究方向为土壤肥力与养分综合管理,E-mail:liuqiuxia@webmail.hzau.edu.cn;通讯作者:鲁剑巍,E-mail:lunm@mail.hzau.edu.cn。
