西北旱区分根交替灌溉苹果树水分利用及蒸发蒸腾量估算研究

发布时间：2018-05-07 20:47

本文选题：分根交替灌溉 + 苹果树　；参考：《中国农业大学》2017年博士论文

【摘要】：西北旱区是我国重要的特色果品生产基地,但水资源短缺是该地区果品生产的重要限制因素,提高灌溉水生产力是该区域果业可持续发展的重要保证。分根交替灌溉是一种创新型的节水技术,它能够减少奢侈蒸腾,提高水分利用效率。因此,研究分根交替灌溉条件下苹果树水分利用及蒸发蒸腾量估算,可为科学制定灌溉制度,促进苹果节水丰产的发展,提供理论依据,对于干旱区经济生态可持续发展具有重要意义。本研究以苹果树为研究对象,于2013-2014年在中国农业大学石羊河实验站布置了两因素田间试验,设3种灌溉方式(高频分根交替灌溉PRIH、低频分根交替灌溉PRIL和常规灌溉CI)和2种灌溉定额(400 mm、500 mm),分析了分根交替灌溉条件下苹果树生理生态和生长特性,揭示了蒸发蒸腾量、产量和水分利用效率变化规律,构建了分根交替灌溉条件下苹果树蒸发蒸腾量估算模型,提出了诊断苹果树水分状况的优化指示参数,取得了如下主要研究成果:(1)揭示了分根交替灌溉条件下苹果树生理生态和生长指标的差异性。与常规灌溉处理相比,分根交替灌溉处理显著降低了苹果树叶片气孔导度和茎叶水势,但对光合速率没有显著影响;提高了苹果树根长密度、根直径、根表面积和根体积,但对根干重的影响不显著;提高了缝隙度和叶倾角,降低了叶面积指数和丛生指数。与低频分根交替灌溉处理相比,高频分根交替灌溉处理降低了苹果树光合速率、气孔导度、茎叶水势、缝隙度和叶倾角,但提高了根系参数、叶面积指数和丛生指数。(2)分析了分根交替灌溉对苹果树蒸发蒸腾量、产量和水分利用效率的影响。与常规灌溉处理相比,分根交替灌溉处理显著降低了苹果树蒸发蒸腾量,提高了产量和水分利用效率。与低频分根交替灌溉处理相比,高频分根交替灌溉处理提高了蒸发蒸腾量、产量和水分利用效率。(3)构建了基于下垫面局部湿润条件下苹果树蒸发蒸腾量估算模型,并评价了上述模型估算干旱区不同灌溉方式条件下苹果树蒸发蒸腾量的准确性和适用性。S-W_(PRI)模型是适合估算干旱区苹果树蒸发蒸腾量的优化模型,它同时提高了分根交替灌溉和常规灌溉条件下实际蒸发蒸腾量的估算精度。(4)探究了基于树干直径日最大收缩量的信号强度(SI_(MDS))诊断分根交替灌溉条件下苹果树水分状况的适用性。在400 mm灌溉定额条件下,分根交替灌溉处理树干直径日最大收缩量(MDS)显著低于常规灌溉处理;而在500 mm灌溉定额条件下,两种灌溉方式MDS之间差异不显著。SI_(MDS)和基于液流量的信号强度(SI_(SF))不受气象因子影响,但MDS与各气象因子均呈显著正相关关系;与SI_(SF)相比,SI_(MDS)在分根交替灌溉条件下与土壤含水量和茎叶水势均呈显著负相关关系。分根交替灌溉处理SI_(MDS)显著低于常规灌溉处理,且两种灌溉方式间SI_(SF)差异不显著。
[Abstract]:Northwest arid region is an important production base of fruit in China, but the shortage of water resources is an important limiting factor of fruit production in this area. Improving the productivity of irrigation water is an important guarantee for the sustainable development of fruit industry in this region. Alternate root irrigation is an innovative water-saving technology, which can reduce extravagant transpiration and improve water use efficiency. Therefore, the research on the estimation of water use and evapotranspiration of apple trees under the condition of alternate root irrigation can provide theoretical basis for the scientific formulation of irrigation system and the development of water saving and high yield of apple. It is of great significance to the sustainable development of economy and ecology in arid area. In this study, two factor field experiments were conducted on apple trees at Shiyang River Experimental Station of China Agricultural University in 2013-2014. Three irrigation methods (high frequency split root alternate irrigation (PRI), low frequency split root alternate irrigation (PRIL) and conventional irrigation CII) and two kinds of irrigation quota (400 mm / 500 mm) were used to analyze the physiological, ecological and growth characteristics of apple trees, and to reveal the evapotranspiration (evapotranspiration). Based on the variation of yield and water use efficiency (Wue), a model for estimating the evapotranspiration of apple trees under alternate irrigation was established, and the optimal indicator parameters for diagnosing the water status of apple trees were put forward. The main research results were as follows: 1) the differences of physiological, ecological and growth indexes of apple trees under the condition of alternate root irrigation were revealed. Compared with the conventional irrigation treatments, the leaf stomatal conductance and the water potential of stem and leaf of apple trees were significantly decreased, but the photosynthetic rate was not significantly affected, and the root length density, root diameter, root surface area and root volume were increased. However, the effect on root dry weight was not significant, and the crevice degree and leaf dip angle were increased, leaf area index and cluster index were decreased. Compared with the low frequency split root alternate irrigation, the high frequency split root alternate irrigation decreased the photosynthetic rate, stomatal conductance, stem and leaf water potential, crevice degree and leaf dip angle, but increased the root system parameters. Leaf area index and cluster index. 2) the effects of alternate root irrigation on evapotranspiration, yield and water use efficiency of apple trees were studied. Compared with conventional irrigation treatment, alternate root irrigation significantly reduced the evapotranspiration of apple trees and increased yield and water use efficiency. Compared with the alternate irrigation treatment with low frequency and split root, the evapotranspiration, yield and water use efficiency (Wue) of apple trees under the condition of local wetting on the underlying surface were improved by the high-frequency alternative irrigation, and a model for estimating the evapotranspiration of apple trees under the condition of local wetting on the underlying surface was established. The accuracy and applicability of the above models in estimating the evapotranspiration of apple trees under different irrigation conditions were evaluated. The S-WSP PRI model is an optimal model for estimating the evapotranspiration of apple trees in arid areas. It also improves the estimation accuracy of actual evapotranspiration under the condition of alternate irrigation and conventional irrigation. It explores the applicability of the signal intensity based on the maximum daily contraction of trunk diameter to diagnose the water status of apple trees under the condition of alternate irrigation. Under the condition of 400mm irrigation quota, the daily maximum shrinkage of trunk diameter in the treatment of alternate root irrigation was significantly lower than that in the conventional irrigation treatment, while under the condition of 500mm irrigation quota, the maximum contraction of trunk diameter was significantly lower than that of the conventional irrigation treatment. There was no significant difference between the two irrigation methods. The MDS) and the signal intensity based on liquid flow were not affected by meteorological factors, but there was a significant positive correlation between MDS and meteorological factors. There was a significant negative correlation between MDS and soil water content and stem and leaf water potential under the condition of alternate root irrigation. Compared with the conventional irrigation treatment, the SI-MDS of the two irrigation methods was significantly lower than that of the conventional irrigation treatment, and there was no significant difference between the two irrigation methods.
【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S661.1

【参考文献】