【作者】 周勋波；

【导师】 陈雨海；

【作者基本信息】 山东农业大学 ， 作物栽培学与耕作学， 2014， 博士

【摘要】 试验于2011-2012、2012-2013冬小麦生长季节和2011、2012、2013夏玉米生长季节，在山东农业大学农学实验站（36°09′N,117°09′E）进行。冬小麦（济麦22）试验采用裂区设计，水分条件分别为0、90和180mm，灌溉时期分别为拔节（GS34）、抽穗（GS48）和灌浆期（GS70），种植方式分别为单-单（SS）、大小行（WN）、单-双（SD）、双-双（DD）；冬小麦在水分池进行，小区面积为3m×3m，种植密度为200×104/hm2。夏玉米（鲁玉14）试验采用完全随机设计，5种株行距分别为：40cm×40cm（RS40）、32cm×50cm（RS50）、27cm×60cm（RS60）、23cm×70cm（RS70）和20cm×80cm（RS80）；夏玉米在大田进行，小区面积为4m×4m。播种密度为62500株/hm2。上述试验均为3次重复。本试验通过种植方式和灌溉（雨养）构建不同农田小生境，测定作物群体变化、产量构成因素、农田小气候、土壤水分特征、植株水信号等，分析不同农田小生境下土壤水分特征与作物水信号、作物生长与农田小气候的关系，明确作物植株水信号对不同种植方式与灌溉（雨养）的响应特点，深化对作物群体水分利用过程的认识，为复杂农田生境的水分利用与产量形成机制提供必要的理论参数。1冬小麦部分1.1冬小麦农田小生境变化土壤温度的日变化与空气温度日变化规律一致，但有一定的滞后效应。在0、90、180mm条件下土壤日均温度分别是20.7、19.7、19.4℃，90mm处理比0mm处理和180mm处理比90mm处理分别低6.8%和4.1%。土壤温度随土壤深度的增加而降低。SD和DD种植方式有利于降低土壤温度。不同种植方式蒸发强度平均值顺序为SS> WN>SD> DD，表明土壤温度较高的蒸发强度大。随灌溉量增加相对湿度有提高趋势。随生育进程推进PAR截获率下降，GS39、GS49、GS71的PAR截获率分别为89.8%、87.4%、81.8%，GS71明显低于GS39和GS49。0、90、180mm条件下的PAR截获率分别为70.6%、79.2%、82.3%，SD和DD在光能截获方面表现一定的优势。1.2冬小麦水信号变化冬小麦生长季节，0、90、180mm处理的水势均值分别为-1.58、-1.50、-1.46MPa，水势随灌水量增加而增加。SS、WN、SD和DD种植方式的水势均值分别是-1.55、-1.52、-1.53和-1.49MPa，表明DD能提高冬小麦水势。水势一天中的日均值与时间呈负相关，且随生育进程推进有下降趋势。SS的渗透势最低，为-1.52MPa。叶片相对含水量与生育阶段呈负相关，相关系数为r=-0.9926（P=0.0008）。0、90、180mm处理的叶片相对含水量和土壤含水量分别是84.8%、85.7%、86.3%和22.5%、25.2%、29.0%，随灌溉量增加而提高；ABA含量分别是24.0、23.9、23.7ng/g；SS、WN、SD、DD的ABA含量和土壤含水量分别为25.3、24.6、23.0、22.4ng/g和22.9%、23.2%、23.1%、23.4%。表明灌溉和DD种植方式可提高土壤含水量、降低ABA含量，减轻水分胁迫。1.3冬小麦生长发育及光合特性0、90、180mm处理干物质增长速率均值分别为19.5、22.4、23.1g/d/m2，根系密度分别为8.7×10-3、9.3×10-3、8.7×10-3，Pn分别为17.6、21.5、23.1μmol CO2/m2/s，CCI、Fv/Fm分别为39.5、39.3、38.5，0.796、0.797、0.802；SS、WN、SD、DD的根系密度和鲜根干重分别为8.3×10-3、8.2×10-3、8.8×10-3、10.3×10-3和1.085、1.114、1.320、1.455mg/cm3，CCI分别为38.4、39.6、39.1、39.2。SD和DD的LAI均值比SS和WN高11.8%。灌溉处理间的Pn变异系数（C·V）为14.2%，种植方式间的变异系数为3.6%，水分条件对Pn的影响程度高于种植方式；灌溉可以提高LAI、Pn、Fv/Fm，但CCI降低。结果表明，SD和DD可以提高CCI、促进根系生长。1.4冬小麦产量与水分利用效率土壤贮水量与生育进程呈显著负线性相关（P <0.05）。0、90、180mm处理的土壤贮水量分别为288.2、296.8、314.9mm，种植方式间无显著差异。0、90、180mm处理，蒸散量分别为335、418、475mm，产量分别为617、766、791g/m2，WUE分别为1.92、1.88、1.68g/m2/mm，RUE分别为0.83%、1.01%、1.07%；SS、WN、SD、DD蒸散量分别为397、421、404、415mm，产量分别为694、708、745、751g/m2，WUE分别为1.83、1.72、1.90、1.86g/m2/mm，RUE分别为0.92%、0.95%、0.99%、1.01%；不同种植方式的产量与蒸散量均符合一元二次回归关系，达显著相关（P<0.01）。灌溉显著增加了单位面积穗数、穗粒数和干物质重；DD的单位面积穗数显著高于SS（P <0.05），WN和SD高于SS；DD和SD的穗粒数显著高于SS；SS、WN、SD、DD的干物质重依次提高，SD和DD显著高于SS（P <0.05）。灌溉后或SD和DD种植方式能提高株高、穗长和小穗数，降低不孕小穗数，灌溉显著增加蒸散量和降低WUE、提高产量和RUE。1.5冬小麦产量与水信号及光合指标的关系0mm条件下，ABA含量与产量呈负相关，蒸发强度与产量呈显著负相关，其它水信号指标与产量均呈正相关。90mm条件下，土壤含水量与水势呈极显著正相关，水势与产量呈显著正相关，ABA含量与产量负相关性达显著水平（P <0.05）。180mm条件下，各因素间相关性规律不明显。0mm条件下，温度较高可能抑制冬小麦产量，其它光合特性指标与产量均呈正相关。90mm条件下，产量与Fv/Fm呈负相关性。180mm条件下，产量与LAI、鲜根干重呈极显著正相关。随灌溉量增加产量与根系生长状况相关性越显著，与LAI相关性达极显著水平，与Pn、CCI相关性逐步下降。因此，产量变化是通过多指标（水信号和光合特性）共同表现的。2夏玉米部分2.1夏玉米农田生境变化土壤温度随生育阶段推进逐步下降，与大气温度变化一致。RS40、RS50、RS60、RS70、RS80，0-15cm土壤温度分别为24.7、25.1、25.2、25.3、25.3℃。PAR截获率，V6阶段最低，R0-R3阶段较高，R4阶段明显下降；R0-R4的PAR总截获率为84.1%，上层（>100cm）为66.6%，下层（0-100cm）为17.6%，上层占比为79.1%；总截获率较高、特别是上层（>100cm）占总截获率较高，有利于产量形成。RS40、RS50、RS60、RS70、RS80的PAR截获率分别为85.6%、86.0%、85.1%、83.3%、80.8%，表明随行距加大光浪费现象严重。2.2夏玉米生长发育及光合特性V6-R4阶段，RS40、RS50、RS60、RS70、RS80的Pn和CCI分别为29.9、31.0、32.1、31.3、28.8μmol CO2/m2/s和43.0、44.4、41.9、41.7、41.0。Fv/Fm顺序为RS40=RS50> RS60> RS70> RS80，RS40和RS50的Fv/Fm均值比RS70和RS80的均值高1.3%。过宽行距（RS80）或降雨较少都会降低LAI。RS40、RS50、RS60处理更有利于干物质积累。RS40、RS50、RS60、RS70、RS80的根系密度2年均值分别为11.7、11.9、13.2、11.5、10.5×10-3，RS60比RS80高25.7%。2.3夏玉米水分指标变化RS40、RS50、RS60、RS70、RS80处理的水势均值分别为-1.36、-1.39、-1.42、-1.50、-1.49MPa，RS40和RS50的均值比RS70和RS80的均值高8.8%，相对窄行距处理有利于提高水势。行距对叶片相对含水量和土壤含水量没有显著影响（P>0.05）。土壤贮水量与生育阶段呈现显著的回归关系，回归方程为y=-11.682x2+72.971x+241.03，R2=0.4798（P=0.009）。2.4夏玉米水分利用效率与产量构成RS40、RS50、RS60、RS70、RS80的WUE和RUE分别为24.2、24.8、23.2、22.0、21.6kg/ha/mm和1.68%、1.67%、1.54%、1.56%、1.56%，RS40和RS50的WUE显著高于其它处理，RS50的RUE显著高于RS80（P <0.05）。行距处理对单粒重没有显著影响，RS40、RS50处理的单株粒数显著高于RS80处理，均值比RS70和RS80处理的均值高9.6%，产量顺序为RS50> RS40> RS60> RS70> RS80，因此，单株粒数是提高产量的关键因素。RS60处理的干物质重显著低于RS40处理，但收获指数比RS80处理高7.1%，表明RS60处理有利于光合产物向籽粒分配。2.5夏玉米产量与水信号及光合指标的关系行距与产量有显著负相关、与水势有极显著负相关，随行距加大水势下降；土壤水分蒸散量与土壤含水量有显著正相关，表明土壤含水量增加提高了蒸散量；产量与相对含水量、水势与相对含水量均呈正相关，表明较高的水势和土壤含水量有利于产量提高。行距与土壤温度呈正相关，与其它光合指标均呈负相关，土壤温度提高仅对Pn有促进作用，对其它光合指标及产量均为负面效应，综合改善CCI、LAI、Fv/Fm、Pn有利于提高产量。综上所述，行距布局科学可提高光截获和优化光分布，株间距合理有利于个体健壮和根系发育，地上与地下部分的协调促进群体生长，提高产量。结果表明，冬小麦0mm结合DD、90mm结合DD、SD，180mm结合SD，夏玉米RS50能改善农田生态环境，其水信号指标、光合特性指标变化，产量构成因素分析等均表明有利于产量、WUE、RUE提高，是较好的种植方式。更多还原

【Abstract】 This research was conducted at the Agronomy Experimental Station of ShandongAgricultural University, Tai’an (36°09′N,117°09′E) in Northern China. The experimentswere conducted during the growing season of winter wheat (Triticum aestivum L.) in2011–2012and2012–2013and the growing season of summer maize (Zea mays L.) in2011,2012, and2013. The experiments were a split-plot design for winter wheat and a randomizedcomplete block design for summer maize, with three replications. The plots were3m×3m(winter wheat) and4m×4m (summer maize) in size. Water conditions were allocated basedon the main plots, and the spacing between rows was based on split-plots. At each of theZadoks growth stages (GSs),0,30, and60mm of water were applied to irrigated winterwheat plants at GS34(stem elongation stage), GS48(booting stage), and GS70(milkdevelopment stage), respectively. Winter wheat (cv. Jimai22) was hand-planted at200×104seeds/ha. The experiment involved four plant population distribution patterns: single-singlerow (SS), wide-narrow row (WN), single-double row (SD), and double-double row (DD).Summer maize seeds (cv. Luyu14) were hand-sown at a seeding rate of62500seeds/ha. Theexperiment involved five plant population distribution patterns under rainfed conditions. Thefollowing row spacing (RS)×spacing between the plant schemes were used:40cm×40cm(RS40),50cm×32cm (RS50),60cm×27cm (RS60),70cm×23cm (RS70), and80cm×20cm (RS80).The experiment focused on the connective and responsive mechanisms betweenfarmland microhabitats and hydraulic signals. These mechanisms included dynamic changesin population structure, yield component, field microclimate, soil water, and hydraulic signalsof plants under different farmland microhabitats of suitable density. The connected effects ofsoil and crop hydraulic signals on crop growth and field microclimate, as well as thequantitative functions of crop morphology, were also determined. This study will provideimportant information on the theoretical parameters for rapid and accurate judgment of timelyand precise irrigation under drought stress, as well as on the hydraulic signals of crop in fieldthat can serve as early warning systems of adverse circumstances. 1Winter wheat experiment1.1Change of farmland microhabitatsDaily changes in soil temperature were consistent with daily air temperature, butexhibited a lag time. Daily soil temperatures of the0,90, and180mm treatments were20.7,19.7, and19.4°C, respectively. The soil temperature of the90mm treatment was6.8%lowerthan that of0mm treatment, and that of the180mm treatment was4.1%lower than that ofthe90mm treatment. Soil temperature decreased with increasing soil depth. SD and DDcould reduce soil temperature. The order of daily soil evaporation was SS> WN> SD> DD,which showed that high soil temperature could increase daily soil evaporation. Relativehumidity exhibited an increasing trend with increasing irrigation amount.Photosynthetically available radiation (PAR) capture ratio exhibited a decreasing trendwith advancing GS, and the PAR capture ratios of GS39, GS49, and GS71were89.8%,87.4%, and81.8%, respectively. The PAR capture ratio of GS71was lower than those ofGS39and GS49. The PAR capture ratios of the0,90, and180mm treatments were70.6%,79.2%, and82.3%, respectively. PAR capture produces benefits under SD and DD conditions.1.2Change in hydraulic signalsDuring the winter wheat growth season, the leaf water potentials of the0,90, and180mm treatments were-1.58,-1.50, and-1.46MPa, respectively. Leaf water potential increasedwith increasing irrigation amount. The leaf water potentials of SS, WN, SD, and DD were-1.55,-1.52,-1.53, and-1.49MPa, which showed that DD could increase leaf water potential.A negative correlation was observed between water potential average and time in a day, and adecreasing trend with advancing GS. The leaf osmotic potential of SS was-1.52MPa, whichwas the lowest among all planting patterns.Significant negative correlations were observed between the leaf relative water content(LRWC) and GS over two years, and the correlation coefficient was r=-0.9926(P=0.0008).The LRWC values of the0,90, and180mm treatments were84.8%,85.7%, and86.3%, andthe soil water contents (SWCs) were22.5%,25.2%, and29.0%, respectively. These valuesincreased with increasing irrigation amount. The abscisic acid (ABA) values of the0,90, and180mm treatments were24.0,23.9, and23.7ng/g, respectively. The ABA values of SS, WN,SD, and DD were25.3,24.6,23.0, and22.4ng/g, and the SWC values were22.9%,23.2%,23.1%, and23.4%, respectively. The results showed that irrigation, SD, and DD couldincrease SWC while decreasing ABA content, which could alleviate water stress.1.3Growth development and photosynthetic characterFor the0,90, and180mm treatments, dry matter weight values were19.5,22.4, and 23.1g/d/m2; root density values were8.7×10-3,9.3×10-3, and8.7×10-3; daily netphotosynthetic rates (Pn) were17.6,21.5, and23.1μmol CO2/m2/s; chlorophyll contentindexes (CCIs) were39.5,39.3, and38.5; and Fv/Fm values were0.796,0.797, and0.802,respectively. The root densities of SS, WN, SD, and DD were8.3×10-3,8.2×10-3,8.8×10-3,and10.3×10-3, their fresh root dry weight (FRDW) values were1.085,1.114,1.320, and1.455mg/cm3, and their CCI values were38.4,39.6,39.1, and39.2, respectively.The average leaf area indexes (LAI) of SD and DD were11.8%higher than those of SSand WN. The variable coefficient of different irrigation treatments was14.2%, whereas that ofdifferent planting patterns was3.6%. The effect of water condition was higher than that ofplanting pattern. Irrigation increases LAI, Pn, and Fv/Fm but decreases CCI. The resultsshowed that SD and DD could increase CCI and improve root growth.1.4Yield and water use efficiencyA significantly negative correlation was observed between soil water storage and GS (P<0.05). The soil water storage values of the0,90and180mm treatments were288.2,296.8,and314.9mm, respectively. No significant influence among planting patterns was observed.For the0,90, and180mm treatments, evapotranspiration values were335,418, and475mm, the yield values were617,766, and791g/m2, water use efficiency (WUE) values were1.92,1.88, and1.68g/m2/mm, and the radiation use efficiency (RUE) values were0.83%,1.01%, and1.07%, respectively. For SS, WN, SD, DD, the evapotranspiration values were397,421,404, and415mm, the yield values were694,708,745, and751g/m2, the WUEvalues were1.83,1.72,1.90, and1.86g/m2/mm, and the RUE values were0.92%,0.95%,0.99%, and1.01%, respectively. A significant quadratic equation of yield andevapotranspiration was found (P <0.01).The irrigation treatments resulted in significantly increased spikes per unit area, grainsper spike, and dry matter weight. The unit area spikes of DD were significantly higher thanthose of SS (P <0.05), whereas those of WN and SD were higher than that of SS. The grainsper spike of DD and SD were significantly higher than that of SS. The dry matter weights ofSS, WN, SD, and DD successively increased, with those of SD and DD being higher than thatof SS (P <0.05). Irrigation, SD, and DD could increase plant height, spike length, andspikelet number while decreasing sterile spikelet number, whereas irrigation could increaseevapotranspiration, yield, and RUE while decreasing WUE.1.5Relationship of yield with hydraulic signals and photosynthetic parametersFor the0mm treatments, yield had a negative correlation with ABA content andevapotranspiration, but a positive correlation with other hydraulic signals. For the90mm treatments, a significantly positive correlation was observed between SWC and leaf waterpotential and between leaf water potential and yield. A significantly negative correlation wasobserved between ABA content and yield (P <0.05). For the180mm treatments, no obvioustrend was observed among factors.For the0mm treatments, high soil temperature was adverse for yield, and a positivecorrelation was found between other photosynthetic parameters and yield. For the90mmtreatments, a significantly negative correlation was observed between yield and Fv/Fm. Forthe180mm treatments, yield exhibited a significantly positive correlation with LAI andFRDW. Irrigation resulted in an increased correlation between yield and root growthdevelopment, as well as between yield and LAI, but a decreased correlation between yield andPn, as well as between yield and CCI. Thus, the synthetic action of different factors exhibitedan influence on yield.2Summer maize experiment2.1Change of farmland microhabitatsDaily changes in soil temperature exhibited a decreasing trend with advancing GS,which was consistent with the trend observed for daily air temperature. At the0–15cm soillayer, the soil temperatures of RS40, RS50, RS60, RS70, and RS80were24.7,25.1,25.2,25.3, and25.3°C, respectively. PAR capture ratio was the lowest at V6, was high at R0–R3atdifferent GSs, and was decreasing at R4. The PAR capture ratio of R0–R4was84.1%. Thisratio was66.6%in the upper layer (>100cm) and17.6%lower layer (0–100cm). The upperlayer accounted for79.1%of the total PAR capture ratio. The high PAR capture ratio of theupper layer could increase yield. The PAR capture ratios of RS40, RS50, RS60, RS70, andRS80were85.6%,86.0%,85.1%,83.3%, and80.8%. The result showed that light lossincreased with increasing RS.2.2Growth development and photosynthetic characterAt V6–R4, the Pn values of RS40, RS50, RS60, RS70, and RS80were29.9,31.0,32.1,31.3, and28.8μmol CO2/m2/s, and the CCI values were43.0,44.4,41.9,41.7, and41.0,respectively. The order of Fv/Fm was RS40=RS50> RS60> RS70> RS80, and the averagesof RS40and RS50were1.3%higher than those of RS70and RS80.Oversized RS (RS80) and reduced rainfall could decrease LAI. RS40, RS50, RS60increased dry matter weight. The root densities of RS40, RS50, RS60, RS70, and RS80were11.7,11.9,13.2,11.5, and10.5×10-3, respectively, and that of RS60was25.7%higher thanthat of RS80. 2.3Change of hydraulic signalsThe leaf water potentials of RS40, RS50, RS60, RS70, RS80were-1.36,-1.39,-1.42,-1.50, and-1.49MPa, respectively, and the average values of RS40and RS50were8.8%higher than those of RS70and RS80. This result showed that narrow RS could increase leafwater potential. RS exhibited no significant effect on LRWC and SWC (P>0.05). Asignificantly quadratic equation of soil water storage and GS was found as follows: y=-11.682x2+72.971x+241.03, R2=0.4798(P=0.009).2.4Yield and water use efficiencyThe WUE values of RS40, RS50, RS60, RS70, and RS80were24.2,24.8,23.2,22.0,and21.6kg/ha/mm, and the RUE values were1.68%,1.67%,1.54%,1.56%, and1.56%,respectively. The WUE values of RS40and RS50were significantly higher than those ofother treatments, and the RUE value of RS50was significantly higher than that of RS80(P <0.05).RS exhibited no significant effect on kernel weight. The per-plant kernel numbers ofRS40and RS50were significantly higher than that of RS80. The order of yield was RS50>RS40> RS60> RS70> RS80. The dry matter weight of RS60was significantly lower thanthat of RS40, but the harvest index was7.1%higher than that of RS80. This finding revealedthat RS60was beneficial for the transfer of photosynthate to grain.2.5Relationship of yield with hydraulic signals and photosynthetic parametersA significantly negative correlation was found between RS and yield, as well as betweenRS and leaf water potential. A positive correlation was observed between evapotranspirationand SWC, yield and LRWC, as well as leaf water potential and LRWC. The results showedthat increasing water potential and SWC resulted in increasing yield.A positive correlation was noted between RS and soil temperature, but a negativecorrelation was observed between RS and other photosynthetic parameters. The relativelyhigh soil temperature improved Pn, but was adverse to other photosynthetic parameters. Theresults showed that the comprehensive action of CCI, LAI, Fv/Fm, and Pn could increaseyield.A reasonable RS could enhance PAR capture ratio and improve PAR distribution, andreasonable plant spacing could improve individual growth and root development. Thecoordination of above–under ground could promote crop growth and increase yield. Theresults showed that the DD planting pattern under0mm, the DD and SD planting patternunder90mm, the SD planting pattern under180mm for winter wheat, and RS50for summermaize could improve the farmland ecology environment, which provides benefits of increased yield, WUE, and RUE.更多还原