覆膜栽培对水稻耗水和节水特性的影响

发布时间：2018-05-05 05:18

本文选题：水稻覆膜栽培 + 水稻耗水　；参考：《中国农业大学》2016年博士论文

【摘要】：传统水稻淹水栽培体系耗水量巨大,水分利用效率低下,由于水资源形势日趋紧张,发展节水稻作生产体系已成为当务之急。在节水稻作生产体系中,水稻覆膜栽培以其显著的节水稳产效果,引起了国内外研究者的广泛关注。目前有关水稻覆膜栽培的研究主要集中在覆膜对水稻生长和产量的影响,而关于覆膜栽培水稻的需水耗水规律、及其节水特性与机理,至今鲜有报道。本研究通过在湖北十堰房县布置田间试验(2013-2014年,共两季),结合室内土柱试验,以传统水稻淹水栽培为对照,探讨了覆膜栽培水稻(覆膜湿润栽培、覆膜旱作栽培)的耗水规律与节水增产机理。本文分析了覆膜栽培水稻的需水、耗水规律与节水特性,探讨了覆膜栽培对水稻群体生长、生理特征和产量的影响,评价了覆膜栽培水稻的水分利用效率；基于根长密度建立了覆膜栽培水稻的根系吸水模型,并将其与考虑根源信号ABA参与调控气孔行为的气孔导度模型相结合,模拟了水稻叶片气孔导度的日变化过程。主要的研究结果如下：(1)与淹水栽培相比,覆膜湿润和旱作栽培水稻整个生长季的总用水量(包括灌溉I和降雨P)分别降低了34.6%和47.4%,其中,灌溉量分别降低了61.3%和83.8%,其主要原因在于：覆膜栽培水稻在各主要环节的耗水(无论是非生理耗水,还是生理耗水)均呈显著降低。非生理耗水方面,覆膜栽培模式的深层渗漏(D)和蒸发损失(E)相对淹水处理分别降低了71.5-88.2%、82.8-89.1%；生理耗水方面,覆膜栽培总体有效降低了水稻的蒸腾耗水需求,使全生育期蒸腾总量(T)较淹水栽培下降6.1-9.7%,但由于不同生育期水稻的叶面积和气孔导度等水分生理指标呈现不尽一致的响应,从而导致覆膜与淹水栽培之间的蒸腾耗水差在水稻生育前期和后期呈现不同的变化趋势。(2)从植物生长来看,田间试验条件下,与淹水栽培相比,覆膜栽培水稻的叶面积和地上部生物量显著提高；最大分蘖期,覆膜栽培水稻的根系生物量、根长密度、根直径相对淹水栽培均显著增加,扬花期却低于淹水栽培水稻(尤其根直径),但覆膜和淹水处理间无显著差异；覆膜栽培水稻的根冠比相对淹水栽培降低。覆膜湿润和旱作栽培水稻的总生物量及产量基本相同,相比淹水栽培分别提高15.7%和11.0%。室内条件下,覆膜湿润栽培的叶面积、地上生物量、根系生物量、根长密度和产量都与淹水栽培无显著差异,而覆膜旱作栽培由于受到长期的水分胁迫,各生长指标和产量均显著降低。(3)由于评价目的不同,水分利用效率(WUE)可有多种计算方法,本研究中涉及的WUE包括：总水分利用效率(WUE1+P,单位面积产量Y与总供水量(即灌溉量I和降雨量P之和)的比值)、灌溉水分利用效率(WUE1,Y与I的比值)、蒸腾水分利用效率(WUEr,单位面积生物量B与蒸腾耗水量T的比值)及叶片尺度水分利用效率(WUEphoto,光合速率Pn与气孔导度gs的比值)。与淹水栽培相比,覆膜湿润栽培的WUE1+P和WUE1分别提高70.7%和194.2%,覆膜旱作则分别提高110.3%和608.7%；覆膜栽培同样显著提高了WUET和WUEphoto;覆膜栽培水稻WUE的提高还同样表现在叶片的813C(稳定碳同位素比值)上：覆膜栽培导致水稻叶片的813C值显著提高,与WUET显著相关。(4)依据水稻的蒸腾耗水所建立的基于根长密度分布的根系吸水模型,能够较好地反映不同土层根系吸水的变化规律。利用根系吸水模型代替彭曼方程,将其与根源信号ABA参与气孔行为调控的气孔导度模型相嵌套,更能确切描述不同土层中根系合成ABA的量、各根系层蒸腾流中ABA浓度及其对木质部最终ABA浓度的贡献、以及最终ABA对气孔导度的调控行为,提高了原模型的模拟精度。
[Abstract]:In this paper , the effects of water - saving and water - saving characteristics on rice growth , water consumption and water - saving characteristics of rice were studied . The effects of film - covered cultivation on growth , physiological characteristics and yield of rice were discussed .
The diurnal variation of stomatal conductance of rice was simulated based on root - length density . The main reasons were as follows : ( 1 ) The total water consumption ( including irrigation I and rainfall P ) decreased by 61.3 % and 47.4 % in the whole growing season of rice . The main reason is that the water consumption of the film - covered and dry - cultivated rice ( including irrigation I and rainfall P ) decreased by 61.3 % and 83.8 % , respectively . The main reason is that the deep leakage ( D ) and evaporation loss ( E ) of the mulching - covered cultivation mode decreased by 71.5 - 88.2 % and 82.8 - 89.1 % respectively .
In the aspect of physiological water consumption , the cultivation of covered film effectively reduced the transpiration water consumption demand of rice , and the total transpiration rate ( T ) of whole growing period decreased by 6.1 - 9.7 % compared with that of the submerged cultivation , but the transpiration water consumption difference between the mulching film and the submerged culture was different in the early and late stages of rice growth .
In the maximum tillering stage , the root biomass , root length , root diameter and root diameter of rice were significantly increased compared with that of rice ( especially root diameter ) , but there was no significant difference between the mulching and flooding treatments .
The ratio of water use efficiency ( ratio of WUE1 + P , ratio of unit area yield Y to total water supply ratio ) , transpiration water use efficiency ( ratio of WUEr , unit area biomass B to transpiration water consumption T ) and water use efficiency ( ratio of WUE photo , photosynthetic rate Pn to stomatal conductance gs ) were studied . Compared with submerged culture , WUE1 + P and WUE1 increased by 70.7 % and 194.2 % , respectively .
( 4 ) The root - root water absorption model is used to replace the Penman equation , which can better reflect the variation law of root water absorption in different soil layers .

【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S511

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