中国农业气象

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节水灌溉和遮光强度对水稻生长发育的耦合影响

李睿,娄运生,张震,马莉,李君   

  1. 1.南京信息工程大学气象灾害预报预警与评估协同创新中心,南京 210044;2.南京信息工程大学江苏省农业气象重点实验室,南京 210044
  • 出版日期:2018-11-20 发布日期:2018-11-13
  • 作者简介:李睿(1993-),女,硕士生,主要从事农业气象研究。E-mail:461917970@qq.com
  • 基金资助:

    国家自然科学基金(41375159);江苏省自然科学基金(BK20131430)

Coupling Effects of Water-Saving Irrigation and Shading Intensity on Growth and Development for Rice

LI Rui, LOU Yun-sheng, ZHANG Zhen, MA Li, LI Jun   

  1. 1.Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044, China; 2.Jiangsu Key Laboratory of Agricultural Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044
  • Online:2018-11-20 Published:2018-11-13

摘要:

采用两因素随机区组试验设计,通过大田模拟试验研究节水灌溉和遮光强度耦合对水稻生长及物候期的影响。灌溉方式设常规灌溉(F,水深5cm)和节水灌溉(W,无水层)2个水平;遮光强度设3个水平,即对照(CK,无遮光,自然光源)、轻度遮光(S1,单层遮光,光合有效辐射减弱60%)和重度遮光(S2,双层遮光,光合有效辐射减弱90%)。在水稻主要生育期即分蘖期、拔节期、抽穗期、灌浆期和成熟期,观测株高、叶面积指数(LAI)、叶绿素含量(SPAD值)、稻穗含水率和冠层高光谱。用冠层高光谱数据提取增强型植被指数(EVI)时间序列,经Spline法插值及小波滤波去噪后预测水稻抽穗盛期的日期。结果表明:随着遮光强度的加重,水稻叶面积指数和叶绿素含量显著下降,物候期明显延迟。节水灌溉对遮光处理下水稻株高和叶绿素含量有抑制作用,对叶面积指数有促进作用,节水灌溉可使遮光处理下水稻物候期提前,使生育期缩短。在一定遮光强度下,水稻冠层光谱反射率在拔节期、抽穗期表现为节水灌溉(W)>常规灌溉(F),而灌浆期、成熟期表现为常规灌溉(F)>节水灌溉(W)。用去噪后的EVI时间序列预测水稻抽穗盛期,准确率为97%。

关键词: 节水灌溉, 遮光强度, 水稻, 生长发育, 物候期

Abstract:

A field experiment was conducted to reveal the coupling effects of water-saving irrigation and shading intensity on rice growth and phenological period. Irrigation was designed with 2 levels, conventional irrigation (F, flooding with 5cm water depth layer) and water-saving irrigation (W, wetting without water layer); shading intensity was set at 3 levels, control (CK, natural light source without shading), light shading (S1, single layer shading, photosynthetically active radiation decreased by 60%) and heavy shading (S2, double layer shading, photosynthetically active radiation decreased by 90%). Rice growth parameters were measured in main stages, tillering, jointing, heading, filling and maturing, which included plant height, leaf area index (LAI), chlorophyll content (SPAD value), and water content in single ear as well as canopy hyperspectral data. Using canopy hyperspectral data to extract the enhanced vegetation index (EVI) time series, heading date was predicted by denoising through spline interpolation and wavelet filtering. The results showed that with higher shading intensity, leaf area index and SPAD value decreased, and phenological periods delayed. Water-saving irrigation inhibited plant height and SPAD value of rice, promoted leaf area index under shading conditions. Water-saving irrigation advanced phenophase and shortened phenological periods of rice under shading conditions. Under the same shading conditions, the spectral reflectance on rice canopy was higher in water-saving irrigation (W) than that in conventional irrigation (F) at jointing stage and heading stage, but higher in conventional irrigation (F) than in water-saving irrigation (W) at filling stage and maturity stage. The denoised EVI time series were used to predict heading date in rice, with prediction accuracy being 97%, and extremely significant correlation (P < 0.01).

Key words: Water-saving irrigation, Shading intensity, Rice, Growth, Phenophase