Light Yield Measurements for PbWO_4 Crystals by Single Photoelectron Method

The measurements of light yield of PbWO4 crystals with normal methods may haverelatively large errors because the crystals have a low light yield.Therefore,a single photoelec-tron method with normal radioactive sources is proposed and the measurements for severalPbWO4 samples produced by Beijing Glass Research Institute are reported.

Gd^(3+) content optimization for mastering high light yield and fast GdxAl_(2)Ga_(3)O_(12):Ce^(3+) scintillation ceramics

Tailoring of the composition of the scintillation ceramics Gd_(x)Ce_(0.03)Al_(2)Ga_(3)O_(12)(x=2.89-3.07) heavily doped with Ce was performed.The co-precipitation is found to be quite a useful method to provide a purpo seful deviation of Gd content from the stoichio metric ratio in powders for their further compacting and sintering in the air.The effect of the composition variations on microstructure,phase composition,luminescent and scintillation characteristics is demonstrated.It is shown that Gd content below the stoichiometric composition leads to increasing the grain size but,quenching of the photoluminescence and the scintillation,whereas excess Gd leads to higher luminosity;the maximum value is obtained for the composition with an excess of Gd ~2%.Ceramics possess a light yield of -50000 ph/MeV,effective scintillation kinetics of 50 ns,and is a good candidate for application in a new generation of scanners utilizing pulsed X-ray sources.

Study on the temperature dependence of BGO light yield

The temperature dependence of BGO coupled with photomultiplier tube R5610A-01 was studied in the range of-30–30℃. The temperature coefficient of the BGO and R5610 A as a whole was tested to be-1.82%/℃. And the temperature coefficient of the gain of the R5610 A is-0.44%/℃ which was tested in the same situation using a blue LED. Thus the temperature coefficient of BGO's light yield can be evaluated as-1.38%/℃.

Effect of Cultivation Pattern on the Light Radiation of Group Canopy and Yield of Spring Soybean (Glycine Max L. Merrill)

Heilongjiang Province is the main soybean-producing area in china. In this study, we analyzed the canopy structure, dynamic characteristics of light radiation and yield of Hefeng50 (the main variety of soybean in Heilongjiang Province) under six different cultivation patterns (ORP, TPCR, ORCP, BRHD, SRHD and FPHD). The results showed that SRHD and BRHD at different growth period (blossom period R1, podding R3 and grain filing period R5) produced an even distribution of the population leaf area, suitable mean foliage inclination angle (MFIA), low transparency coefficients for defuse penetration (TCDP) and transparency coefficients for radiation penetration (TCRP), high leaf area index (LAI), extinction light coefficient (K value), fraction of radiation intercepted (FRI) and light energy utilization rate. Grain number, dry matter weight per plant, and yield of SRHD and BRHD were significantly higher than those of other cultivation patterns. The yield of SRHD, BRHD, ORCP, FPHD and TPCR was increased by 136%, 112%, 79%, 50.1% and 14.7%, respectively, compared to that of ORP. These results suggest that SRHD and BRHD are the optimal cultivation pattern for the improvement of soybean yield in phaeozem region of northeastern China.

Effects of Low Light on Agronomic and Physiological Characteristics of Rice Including Grain Yield and Quality

Light intensity is one of the most important environmental factors that determine the basic characteristics of rice development. However, continuously cloudy weather or rainfall, especially during the grain-filling stage, induces a significant loss in yield and results in poor grain quality. Stress caused by low light often creates severe meteorological disasters in some rice-growing regions worldwide. This review was based on our previous research and related research regarding the effects of low light on rice growth, yield and quality as well as the formation of grain, and mainly reviewed the physiological metabolism of rice plants, including characteristics of photosynthesis, activities of antioxidant enzymes in rice leaves and key enzymes involved in starch synthesis in grains, as well as the translocations of carbohydrate and nitrogen. These characteristics include various grain yield and rice quality components （milling and appearance as well as cooking, eating and nutritional qualities） under different rates of shading imposed at the vegetative or reproductive stages of rice plants. Furthermore, we discussed why grain yield and quality are reduced under the low light environment. Next, we summarized the need for future research that emphasizes methods can effectively improve rice grain yield and quality under low light stress. These research findings can provide a beneficial reference for rice cultivation management and breeding program in low light environments.

Improving Light Oil Yield, an Important Way to the Sustainable Development of Petroleum

Oil resources are non- renewable and the utilization of oil resources should be sustainable andrational. Oil processing industry must, to the maximum extent, produce liquid transportation fuel and chemi-cal feedstocks, which can hardly be replaced by other forms of energy. Restructuring oil refineries in China,developing hydrocracking technologies and improving light oil yield are the significant means to achievethe sustainable development of petroleum processing industry.

Genotypic variation in spatiotemporal distribution of canopy light interception in relation to yield formation in cotton

Background: Within-canopy interception of photosynthetically active radiation(PAR) impacts yield and other agronomic traits in cotton(Gossypium hirsutum L.). Field experiments were conducted to investigate the influence of 6 cotton varieties(they belong to 3 different plant types) on yield, yield distribution, light interception(LI), LI distribution and the relationship between yield formation and LI in Anyang, Henan, in 2014 and 2015.Result: The results showed that cotton cultivars with long branches(loose-type) intercepted more LI than did cultivars with short branches(compact-type), due to increased LI in the middle and upper canopy. Although loose-type varieties had greater LI, they did not yield significantly higher than compact-type varieties, due to decreased harvest index. Therefore, improving the harvest index by adjusting the source-to-sink relationship may further increase cotton yield for loose-type cotton. In addition, there was a positive relationship between reproductive organ biomass accumulation and canopy-accumulated LI, indicating that enhancing LI is important for yield improvement for each cultivar. Furthermore, yield distribution within the canopy was significantly linearly related to vertical LI distribution.Conclusion: Therefore, optimizing canopy structure of different plant type and subsequently optimizing LI distribution within the cotton canopy can effectively enhance the yield.

The energy response of LaBr_(3)(Ce),LaBr_(3)(Ce,Sr),and NaI(Tl)crystals for GECAM

The GECAM series of satellites utilizes LaBr_(3)(Ce),LaBr_(3)(Ce,Sr),and NaI(Tl)crystals as sensitive materials for gamma-ray detectors(GRDs).To investigate the nonlinearity in the detection of low-energy gamma rays and address the errors in the calibration of the E-C relationship,comprehensive tests and comparative studies of the three aforementioned crystals were conducted using Compton electrons,radioactive sources,and mono-energetic X-rays.The nonlinearity test results of the Compton electrons and X-rays demonstrated substantial differences,with all three crystals presenting a higher nonlinearity for X/-rays than for Compton electrons.Despite the LaBr_(3)(Ce)and LaBr_(3)(Ce,Sr)crystals having higher absolute light yields,they exhibited a noticeable nonlinear decrease in the light yield,especially at energies below 400 keV.The NaI(Tl)crystal demonstrated an"excess"light output in the 6-200 keV range,reaching a maximum"excess"of 9.2%at 30 keV in the X-ray testing and up to 15.5%at 14 keV during Compton electron testing,indicating a significant advantage in the detection of low-energy gamma rays.Furthermore,we explored the underlying causes of the observed nonlinearity in these crystals.This study not only elucidates the detector responses of GECAM,but also initiates a comprehensive investigation of the nonlinearity of domestically produced lanthanum bromide and sodium iodide crystals.

不同苜蓿品种叶片特征、光合生理特性与产量性状的比较

以国内外引进的8个紫花苜蓿(Medicago sativa L.)品种为试验材料,对比研究不同品种的叶片特征、产量性状和光合生理特性,采用相关性分析和通径分析法,探讨其与产量的关联性,以期为高产紫花苜蓿种质的筛选提供依据。结果表明:供试紫花苜蓿品种单株干重的变幅为0.88~1.21 g;各性状与单株干重的相关性按大小排序依次为:单株叶干重>比叶重>蒸腾速率>单株叶片数>叶形指数,单株叶干重是最突出的叶片特征指标。对单株干重的影响程度从大到小依次为:比叶重>气孔导度>可溶性蛋白>株高>蔗糖>可溶性糖>叶绿素总量,其中,比叶重是单株干重的主要决定因子。综上,高产紫花苜蓿种质筛选的重要指标包括:单株叶干重和比叶重,8个紫花苜蓿品种中‘甘农9号’、‘WL319HQ’和‘SG501’的单株干重、单株叶干重和比叶重均较大,可作为高产种质在育种工作中加以研究利用。

强筋小麦群体结构、光能利用及籽粒产量对种植密度与追氮模式的响应

为探索强筋小麦高产高效的种植密度及追氮模式,以强筋小麦品种师栾02-1为供试材料,采用裂区试验,种植密度为主区(设置180万、240万、300万、360万和420万株·hm^(-2)五个密度水平),追氮模式为副区(设置拔节期单追、拔节期+开花期分追两种模式),分析了氮密互作对强筋小麦群体大小、光能利用及产量的影响。结果表明,随种植密度的增加,小麦拔节期植被指数和总茎数逐渐提高,花后21 d各层次光合有效辐射透射率则不断降低;在300万~360万株·hm^(-2)密度基础上增加或降低种植密度对开花期总茎数、花后28 d植被指数、灌浆中后期旗叶净光合速率以及籽粒产量均无显著提升效果。与拔节期+开花期分追相比,拔节期单追氮肥有利于提高小麦拔节期植被指数、开花期总茎数、花后21~28 d的旗叶净光合速率、穗数和籽粒产量。与追氮模式和氮密互作相比,种植密度是调控强筋小麦师栾02-1群体结构、光能利用及籽粒产量的最主要栽培因素。合理密植配合拔节期单追氮肥具有协同提高强筋小麦籽粒产量和光能利用的潜力。本试验条件下,种植密度为300万~360万株·hm^(-2)配合拔节期追氮是强筋小麦师栾02-1获得、高产高效的最优模式。

高光产额SrI_(2)Eu^(2+)晶体制备及其闪烁性能研究

SrI_(2)Eu^(2+)晶体因其极高的光产额和优良的能量分辨率,在伽马射线高分辨测量中呈现出良好的应用前景。采用改进的坩埚下降法制备出掺杂浓度为5.0%的SrI_(2)Eu^(2+)晶体,加工制成了直径为25 mm,厚度分别为3,6,9,12 mm的单透光防潮封装SrI_(2)Eu^(2+)闪烁体。研究了4种不同尺寸闪烁体对^(241)Am,^(137)Cs,^(60)Co放射源伽马射线的响应,测试了SrI_(2):Eu^(2+)晶体的荧光光谱、能量分辨率、发光产额及衰减时间等闪烁性能。实验结果表明:SrI_(2)Eu^(2+)晶体的发光光谱峰值位于436 nm,SrI_(2)Eu^(2+)晶体闪烁性能随晶体厚度减薄或伽马射线能量的提高而提升。3 mm厚度SrI_(2)Eu^(2+)闪烁体对1.173 MeV^(60)Co伽马射线的能量分辨率达到了2.74%,在^(137)Cs源伽马射线激发下,光产额达到1.23×10^(5)MeV^(-1),是传统NaI:Tl闪烁体光产额的3倍以上,与当前国际上报道的最好的实验结果相当。

不同施氮量下玉米生长及产量对间作豆科绿肥的响应

【目的】明确不同施氮量下玉米生长及产量对间作豆科绿肥的响应,为构建干旱灌区基于绿肥的玉米氮肥节约型生产模式提供依据。【方法】采用裂区试验设计,主区设玉米间作箭筈豌豆(M||V)和单作玉米(SM)2种种植模式,副区设5个施氮水平:地方推荐施氮量N360(360 kg·hm^(-2))、减量25%施氮N270(270 kg·hm^(-2))、减量50%施氮N180(180 kg·hm^(-2))、减量75%施氮N90(90 kg·hm^(-2))、不施氮N0。对玉米叶面积指数(LAI)、叶日积(LAD)、光能利用率、干物质积累量及产量进行了相关研究。【结果】间作绿肥能够提高减量施氮(N270、N180、N90、N0)条件下玉米出苗后75—150 d的LAI,并增加其全生育期LAD和光能利用率。在N270、N180、N90、N0下,M||V较SM玉米75—150 d LAI、全生育期总LAD、光能利用率平均显著提高了9.8%、8.2%、4.6%。在M||V中,N270与N360的玉米出苗后75—150 d LAI、全生育期总LAD、光能利用率之间没有显著差异,而显著高于其他施氮水平;在SM中,玉米出苗后75—150 d的LAI、全生育期总LAD、光能利用率随施氮量的减少而降低。间作绿肥显著提高了N270、N180、N90、N0条件下玉米出苗后90—150 d的干物质积累量,在同一氮肥减量条件(N270、N180、N90、N0)下,M||V较SM的玉米干物质积累量平均显著提高了4.6%。在玉米出苗后75—130 d,M||V较SM的玉米群体生长率显著提高了5.9%。M||V较同一减量施氮(N270、N180、N90、N0)条件下的SM玉米籽粒产量平均显著提高了8.5%。在M||V中,N270的籽粒产量显著高于N360。M||V较SM玉米穗粒数和千粒重分别平均显著提高6.0%和6.3%。拟合曲线结果表明,间作绿肥可以使玉米在施氮量261.4 kg·hm^(-2)时获得最高产量14876.4 kg·hm^(-2),而单作玉米获得最高产量14012.5 kg·hm^(-2)时的最佳施氮量为348.6 kg·hm^(-2)。减量施氮对绿肥鲜草产量和绿肥氮素积累量的影响显著,M||V N270较M||V N360、M||V N90、M||V N0的绿肥鲜草产量分别显著高了3.8%、4.6%、9.7%,较M||VN90和M||VN0之间的绿肥氮素积累量显著高了5.3%和11.9%。间作绿肥主要通过提高玉米的干物质积累总量,进而增加减量施氮条件下玉米的穗粒数和千粒重,从而使间作玉米在氮肥减量下能够获得较高水平的籽粒产量。【结论】间作豆科绿肥可使氮肥减量25%的玉米获得高于地方推荐施氮量单作玉米的产量水平,可作为试区以及相似生态区域玉米化学氮肥减量的推荐生产模式。

增氧灌溉对温室番茄生长及光响应特征的影响

为提高温室番茄产量和光能利用能力,基于温室盆栽试验,设置了3个溶解氧质量浓度梯度5,15,25 mg/L(即处理A1,A2和A3),采用直角双曲线模型、非直角双曲线模型等6种模型对温室番茄叶片进行了光响应曲线拟合,分析了不同增氧水平对温室番茄生物量、产量、光响应曲线模型及光响应参数的影响.结果表明:处理A2下番茄地上部鲜质量、干质量,地下部鲜质量、干质量,根冠比和产量均达到最大,较处理A1分别提升了25.65%,17.62%,13.35%,36.80%,16.25%和33.82%(P<0.05).番茄地上部质量和产量与气孔导度(G S)、胞间CO 2浓度(C i)和蒸腾速率(T r)呈极显著正相关,地下部干质量与G S,C i呈显著正相关,与T r呈极显著正相关.处理A2下温室番茄叶片的最大净光合速率(P n max)、光饱和点(LSP)、暗呼吸速率(R d)和表观量子效率(α)等光响应参数达到最大,光补偿点(LCP)达到最小.6种模型中,直角双曲线修正模型拟合的光响应曲线其R 2最大,均高于0.992,而RMSE和MAE最小,分别在0.447和0.383以下;对P n max,LSP,LCP和R d等参数的拟合值更接近于实测值.因此,溶解氧质量浓度为15 mg/L更有助于温室番茄高产;直角双曲线修正模型是适合增氧灌溉下温室番茄光响应曲线拟合的最优模型.

施氮对夏花生产量、品质及光温生理特性的影响

氮肥不合理施用在导致资源浪费的同时,还会影响花生正常生长发育和产量品质的形成。探究不同施氮量对夏花生产量、品质及氮素积累动态、光温生理特性和根系形态影响效应,可以为花生高效科学施用氮肥提供依据。本研究在2021—2022年于河南省焦作市温县布置氮肥用量田间试验,供试品种为‘豫花22’,设0 kg·hm^(−2)、45 kg·hm^(−2)、90 kg·hm^(−2)、135 kg·hm^(−2)和180 kg·hm^(−2)5个氮肥用量处理,于成熟期测定夏花生荚果产量和品质指标,并分别于苗期、花针期、结荚期、饱果期测定叶片叶绿素相对含量值(SPAD值)、冠层光合有效辐射和冠层温度,采集植株样品分析植株氮积累量和根系形态。结果表明,随施氮量增加,两年花生荚果产量均呈“线性+平台”趋势变化,适宜施氮量分别为150 kg·hm^(−2)和113 kg·hm^(−2),施氮处理两年平均增产18.86%。成熟期籽粒粗蛋白、含油量和总氨基酸含量均随施氮量增加呈“先升高后趋于稳定”的趋势变化。与不施氮相比,施氮处理籽粒粗蛋白、含油量和总氨基酸含量两年平均增幅分别为7.51%、3.10%和10.08%,效果显著。通过Logistic生长曲线回归拟合,得出施氮处理通过提高花生氮素最大积累速率和平均积累速率,加速快速积累期与吸收峰值的出现,进而提高花生氮素最大积累量;适量施氮提高各部位氮素吸收积累量,促进氮素向荚果中分配。各生育期冠层最高温度、最低温度与平均温度均随施氮量的增加呈先降低后增加的趋势;花生叶片SPAD值与冠层吸收性光合有效辐射量和分量在施氮量为135 kg·hm^(−2)时显著增加,施氮后花生各生育期根系总长、总表面积、总体积和根平均直径分别增加41.03%、22.36%、38.71%和12.19%。氮肥利用率在施氮量为135 kg·hm^(−2)时最大,氮肥农学效率和氮肥偏生产力随施氮量的增加逐渐降低。合理施氮可显著提高夏花生产量、改善品质、促进氮素积累利用并显著改善生育期光温生理性能。本试验条件下夏花生推荐施氮量为110~150 kg·hm^(−2)。

施磷对夏花生产量品质、光温生理特性及根系形态的影响

探究不同施磷水平对夏花生产量、品质及磷素积累动态、光温生理特性和根系形态影响效应,为花生高效科学施用磷肥提供理论支持。2021—2022年在河南省温县布置磷肥用量田间试验,供试品种为“豫花22”,设P2O50、30、60、90、120 kg hm^(-2)5个磷肥用量处理。于成熟期测定夏花生荚果产量和品质指标,并分别于苗期、花针期、结荚期、饱果期测定叶片SPAD值、冠层光合有效辐射和冠层温度,采集植株样品分析植株磷素积累量和根系形态。结果表明,随施磷量增加,2年夏花生荚果产量均呈“线性+平台”趋势变化,适宜施磷量分别为94 kg hm^(-2)和95 kg hm^(-2),施磷处理2年平均增产23.68%。成熟期籽粒粗蛋白、含油量和氨基酸含量均随施磷量增加呈“先升高后趋于稳定”趋势变化。与不施磷相比,施磷90 kg hm^(-2)时籽粒粗蛋白、含油量和氨基酸含量2年度平均增幅分别为11.06%、3.89%和11.58%,效果显著。通过Logistic方程对夏花生磷素积累量进行非线性回归拟合,得出施磷处理通过提高夏花生磷素最大积累速率(V_(m))和平均积累速率(V),延长快速积累期(Δt)与活跃积累期(T_(aas)),进而提高磷素最大积累量(Y_(m));适量施磷提高各部位磷素吸收积累量,促进磷素向荚果中分配。夏花生冠层最高温、最低温与平均温均随施磷量的增加显著降低;叶片SPAD值与冠层光合有效辐射量(APAR)和分量(FPAR)在施磷90 kg hm^(-2)时显著增加;施磷处理夏花生耕层总根长、根平均直径、根体积和根表面积分别平均增加48.50%、16.25%、37.80%和21.88%。磷肥利用率和偏生产力随施磷量增加逐渐降低,农学效率呈先升高后降低的变化趋势。合理施磷可显著提高夏花生产量、改善品质,促进磷素积累利用并显著改善生育期光温生理性能。本试验条件下夏花生推荐施磷量为90 kg hm^(-2)。

光照、氮素对杂交水稻干物质积累、分配和产量形成的影响

为了提高西南喀斯特山区的水稻产量,以Y两优900和宜香优2115为材料,采用裂区试验设计,设置花后遮光为主区因素(自然光照和遮光40%),氮肥为副区因素(90、180、270 kg/hm^(2)),研究光照、氮素及其互作对杂交水稻干物质积累、转运和产量形成的影响。结果表明:同一氮肥水平下,花后遮光40%可显著提高干物质转运量、转运率和贡献率,但也显著降低了花后干物质量、总干物质量、收获指数和结实率,最终导致水稻实际产量显著降低27.0%~31.3%。相同光照条件下,增施氮肥可显著提高有效穗数、单位面积总颖花数、干物质积累与转运量、收获指数和产量。在弱光条件下,增施氮肥能提高干物质转运量、转运率、贡献率和总颖花数,并且总干物质量、收获指数和结实率随着施氮量增多而提高,从而降低了花后弱光造成的产量损失。因此,在西南寡照区,适当增加氮肥的施用,扩大前期的群体和干物质积累量,能有效地补偿后期弱光造成的产量损失。

牛舍灯光不同光照参数对云南泌乳牛群产奶量的影响

本文旨在分析牛舍灯光的光照时间、色温及照度对云南高原地区泌乳牛群产奶量的影响,将50头处于3~4胎、第2~3泌乳月的荷斯坦牛平均分成10组,其中任选1组作为对照组,其余9组分别在光照时间为10h/d、15h/d与18h/d,灯光色温为3000k、4000k与5000k,灯光照度为100lx、150lx和200lx的光照参数下进行试验。结果表明:①在不考虑灯光色温和灯光照度因素影响时,光照时间为15h/d的试验奶牛泌乳量极显著高于10h/d与18h/d的(P<0.05);②在不考虑光照时间和灯光照度因素影响时,灯光色温3000k的试验奶牛泌乳量极显著高于灯光色温4000k与灯光色温5000k的(P<0.05);③在不考虑光照时间和灯光色温因素影响时,灯光照度200lx的试验奶牛泌乳量极显著高于150lx与100lx的(P<0.05);在同时考虑光照时间、灯光色温和灯光照度因素组合影响时,试验奶牛在光照时间为15h/d、灯光色温为3000k与灯光照度为200lx的光照方式下,奶牛的产奶量显著高于其他灯光组合方式(P<0.05)。综合分析表明,在光照时间为15h/d、色温为3000k与照度为200lx的灯光方式下试验奶牛的产奶量较高,并以此为依据对泌乳牛舍的灯光控制时间、色温和照度的调节参数进行了设置,以改善泌乳牛舍的光照环境,提高泌乳牛的灯光福利。

不同播期温光条件对籼稻产量和品质的影响

为明确豫南稻区籼稻高产优质的温光条件,采用大田试验,以3个籼稻品种(兆优5431、中浙优8号和Y两优900)为试验材料,连续2 a研究不同播期[4月15日(T1)、4月30日(T2)、5月15日(T3)、5月30日(T4)和6月14日(T5)]下籼稻抽穗至成熟的积温、累积光照时间、累积光照强度和产量及稻米加工品质、外观品质、营养品质、蒸煮品质,并进行不同播期下温光因子对籼稻稻米品质影响的冗余分析(RDA),通过温光因子的解释率找出影响豫南稻区稻米品质的关键环境因子。结果表明,随着播期的推迟,3个籼稻品种的产量、加工品质和营养品质均呈现先上升后下降的趋势,2 a均表现为T2处理产量最高,加工品质、外观品质和蒸煮品质较好,T5处理产量和品质表现最差。其中,2019年T2处理产量较T5处理提高129.4%,整精米率提高32.1%,垩白度、垩白粒率分别降低69.8%、69.9%,直链淀粉含量降低13.7%;2020年T2处理产量较T5处理提高271.0%,整精米率提高83.9%,垩白度、垩白粒率分别降低85.2%、77.6%,直链淀粉含量降低19.2%。稻米蛋白质含量则是T3处理最高,2019年和2020年T3处理较T5处理分别提高13.6%和20.0%。T2与T3处理间各品质指标差异均不显著。2 a产量均以T2处理下Y两优900最高,且其品质较好。3个品种抽穗到成熟阶段的积温、累积光照时间、累积光照强度均随着播期的推迟呈下降趋势,其中Y两优900的积温和累积光照时间下降幅度最大,兆优5431和中浙优8号下降幅度相当。RDA和解释率分析发现,水稻抽穗至成熟阶段的温光因子是造成稻米品质差异的主要环境因素,抽穗后10~20 d的累积光照时间是影响稻米品质的最主要生态因子。综上,豫南稻区籼稻以4月30日播种产量最高,且品质较好。

植物工厂LED光质调控对芹菜生长及产量的影响

为探讨植物工厂中不同光质对芹菜生长的影响,本研究选用4种不同红蓝光配比的LED光源开展试验。结果表明,红光∶蓝光=3∶1的光质配比下,芹菜株高、茎粗、叶片数、单株鲜重、干重、地上部干重和地下部干重均最大,有利于芹菜的营养生长;红光∶蓝光=3∶1的光质配比可提高芹菜叶绿素含量,促进光合作用,提高光能转化率;红光∶蓝光=3∶1的光质配比有利于芹菜壮苗培育和产量的提高。综合各指标表明,红光∶蓝光=3∶1是适于植物工厂芹菜生长的光质配比。

施钾对夏玉米产量、钾素积累动态及光温生理特性的影响

为给夏玉米科学施钾提供参考依据,2021—2022年在河南省温县开展钾肥用量田间试验,以‘隆玉369’为试验材料,研究0 kg∙hm^(−2)(K0)、40 kg∙hm^(−2)(K40)、80 kg∙hm^(−2)(K80)、120 kg∙hm^(−2)(K120)和160 kg∙hm^(−2)(K160)5个钾(K2O)肥用量对夏玉米株高、叶面积、叶片SPAD值、冠层光合有效辐射、冠层温度和抗氧化酶活性等理化指标及钾素利用效率的影响。结果表明:2021年和2022年施钾处理分别增产4.9%~6.6%和7.4%~9.6%,且产量增幅随钾肥用量增加呈“先升高后趋于稳定”趋势,最佳施钾量分别为80 kg·hm^(−2)和87 kg·hm^(−2)。施钾可提升夏玉米株高、叶面积和叶片SPAD值,促进夏玉米生长发育和干物质积累。Logistic方程拟合表明,钾素吸收总量与最大积累速率以K80、K120最佳,分别较K0提高22.5%、28.3%与29.2%、37.5%,此外,最大速率出现时间缩短3~4 d。进一步研究表明,施钾(K2O)量为80~120 kg·hm^(−2)可有效增强夏玉米群体光合有效辐射分量,降低冠层温度,提升超氧化物歧化酶、过氧化物酶和过氧化氢酶活性。综上所述,施钾可提高夏玉米产量,促进夏玉米生长发育和钾素吸收利用,增强各生育期光温生理特性和抗氧化酶活性,豫北夏玉米适宜施钾(K2O)量为80~120 kg·hm^(−2)。