Humic Acid Effects on Reducing Corn Leaf Burn Caused by Foliar Spray of Urea-Ammonium Nitrate at Different Humic Acid/Urea-Ammonium Nitrate Ratios

Technologies for reducing corn leaf burn caused by foliar spray of urea-ammonium nitrate (UAN) during the early growing season are limited. A field experiment was carried out to evaluate the effects of humic acid on corn leaf burn caused by foliar spray of undiluted UAN solution on corn canopy at Jackson, TN in 2018. Thirteen treatments of the mixtures of UAN and humic acid were evaluated at V6 of corn with different UAN application rates and different UAN/humic acid ratios. Leaf burn during 1 2, 3, 4, 5, 6, 7, and 14 days after UAN foliar spray significantly differed between with or without humic acid addition. The addition of humic acid to UAN significantly reduced leaf burn at each UAN application rate (15, 25, and 35 gal/acre). The reduction of leaf burn was enhanced as the humic acid/UAN ratio went up from 10% to 30%. Leaf burn due to foliar application of UAN became severer with higher UAN rates. The linear regression of leaf burn 14 days after application with humic acid/UAN ratio was highly significant and negative. However, the linear regression of leaf burn 14 days after application with the UAN application rate was highly significant and positive. In conclusion, adding humic acid to foliar-applied UAN is beneficial for reducing corn leaf burn during the early growing season.

Effects of Different Sowing Times on Plant Height, Leaf Stem Ratio and DW/FW Ratio of Forage Sorghum in Autumn Idle Land

The aim was to explore the linear regression prediction models between sowing time and plant height, leaf stem ratio and DW/FW ratio of forage sorghum in autumn idle land. [Method] The relationships between sowing time and plant height, leaf stem ratio and DW/FW ratio of forage sorghum were simulated and compared by employing field plot experiment and linear regression analysis. [Result] The sowing time had a great impact on plant height, leaf stem ratio and DW/FW ratio of forage sorghum in autumn idle land. With the delay of sowing time, the plant height and DW/FW ratio of forage sorghum decreased, while the leaf stem ratio increased. The regression models between sowing time and plant height, leaf stem ratio and DW/FW ratio of forage sorghum were established： plant height and sowing time, yheight = 234.725- 5.005X; leaf stem ratio and sowing time,ylcaf= 0.096 ＋ 0,019x; DW/FW ratio and sowing time, ydry= 0.305-0.002X. From July 23rd to August 30th, the plant height of forage sorghum was reduced by 5.005 cm, the leaf stem ratio was increased by 0.019 and the DW/FW ratio was reduced by 0.002 in average when hhe sowing time was delayed by one day. [Conclusion] This study provides a theoretical support for the production of forage sorghum in autumn idle land.

Effect of nitrogen and phosphorus addition on leaf nutrient concentrations and nutrient resorption efficiency of two dominant alpine grass species

Nitrogen(N)and phosphorus(P)are two essential nutrients that determine plant growth and many nutrient cycling processes.Increasing N and P deposition is an important driver of ecosystem changes.However,in contrast to numerous studies about the impacts of nutrient addition on forests and temperate grasslands,how plant foliar stoichiometry and nutrient resorption respond to N and P addition in alpine grasslands is poorly understood.Therefore,we conducted an N and P addition experiment(involving control,N addition,P addition,and N+P addition)in an alpine grassland on Kunlun Mountains(Xinjiang Uygur Autonomous Region,China)in 2016 and 2017 to investigate the changes in leaf nutrient concentrations(i.e.,leaf N,Leaf P,and leaf N:P ratio)and nutrient resorption efficiency of Seriphidium rhodanthum and Stipa capillata,which are dominant species in this grassland.Results showed that N addition has significant effects on soil inorganic N(NO_(3)^(-)-N and NH_(4)^(+)-N)and leaf N of both species in the study periods.Compared with green leaves,leaf nutrient concentrations and nutrient resorption efficiency in senesced leaves of S.rhodanthum was more sensitive to N addition,whereas N addition influenced leaf N and leaf N:P ratio in green and senesced leaves of S.capillata.N addition did not influence N resorption efficiency of the two species.P addition and N+P addition significantly improved leaf P and had a negative effect on P resorption efficiency of the two species in the study period.These influences on plants can be explained by increasing P availability.The present results illustrated that the two species are more sensitive to P addition than N addition,which implies that P is the major limiting factor in the studied alpine grassland ecosystem.In addition,an interactive effect of N+P addition was only discernable with respect to soil availability,but did not affect plants.Therefore,exploring how nutrient characteristics and resorption response to N and P addition in the alpine grassland is important to understand nutrient use strategy of plants in terrestrial ecosystems.

Study on the Relationship of Seedling Density and Line Spacing to Leaf-stem Ratio, DW/FW Ratio and Grass Yield of Forage Sweet Sorghum

[ Objectives ] The aim was to optimize the configuration of seedling density and line spacing of forage sweet sorghum （ Sorghum blcolor （ L. ） Moench） and explore its high-yield cultivation techniques. [ Methods] Effects of such two influencing factors as line spacing and seedling density on the leaf-stem ratio, DW/FW ratio and grass yield of forage sweet sorghum were analyzed by using split-plot experiment design experiment method and LSD method of IBM. SPSS. Statis- tics. v22 stati, stics software. [ Results ~ Seedling density and line spacing had no obvious effect on the leaf-stem ratio and DW/FW ratio of forage sweet sorghum but had obvious influences on the grass yield. Moreover, the optimal combination of seedling density and line spacing for high yield of forage sweet sorghum was A2 B4, that is, seedling density was 225 000 plants/hm2, and line spacing was 40 cm. [ Conclusions] The results provided a theoretical basis and technical support for high-yield cultivation techniques of forage sweet sorghum.

Low Ca^2＋ Content and Ca^2＋/Na^＋ Ratio in Leaf Tissues Determine Salinity Tolerance in Spanish Type Groundnut （Arachis hypogeal L.）

The study was performed with seven groundnut varieties/genotypes and F1s derived from crossing in all possible combinations without reciprocal among the mentioned varieties/genotypes. The objective was to assess whether low Ca2＋ content and Ca2＋/Na＋ ratio of leaf tissue or stem tissue determine salinity tolerance in terms of economic yield （kernel yield） in groundnut. It revealed that the varieties, “Binachinabadam-6”, “Binachinabadam-5” and the F1 G2 × G3 were most tolerant based on kernel yield under 8 dS/m and 10 dS/m salinity stresses. These two tolerant varieties and the F1 also showed lower Ca2＋ and Ca2＋/Na＋ ratios in leaf tissue, which indicated lower Ca2＋ and Ca2＋/Na＋ ratio of leaf tissue determined salinity tolerance in terms of kernel yield in Spanish type groundnut. These findings could be applied in future plant breeding applications for screening salt tolerant Spanish type groundnut genotypes.

不同叶果比对设施‘红美人’杂柑秋梢叶片生理生化特征的影响

为探究不同叶果比(leaffruitratio,LFR)对设施柑橘秋梢叶片生理生化特征的影响,以设施栽培‘红美人’杂柑为试材,设置高(LFR=100)、中(LFR=80)、低(LFR=60)3个叶果比,测定秋梢叶片中矿质元素、碳氮代谢物、碳氮代谢的关键酶、抗氧化酶活性等生理指标的变化。结果显示,LFR80和LFR100秋梢叶片的磷、钾、镁、淀粉含量较高;丙二醛、脯氨酸、抗坏血酸含量较低;β-淀粉酶、硝酸还原酶、谷氨酰胺合成酶和抗坏血酸过氧化物酶的活性较高;LFR80和LFR100秋梢叶片整体养分含量充足,受胁迫程度较低。结果表明,设施栽培‘红美人’杂柑的叶果比控制在80~100有利用于平衡营养生长和生殖生长,延缓叶片衰老,维持树势强健。

不同性质艾柱燃烧红外光谱特征研究

目的 探索不同性质艾柱的燃烧红外光谱特征。方法 选取碳化艾柱及不同存储年份(3、5、10年)、不同叶绒比(3∶1、5∶1、10∶1)、不同紧密度(低、中、高)的普通艾柱做为实验样品,使用傅立叶红外变换光谱仪对样品进行燃烧红外光谱测试,并分析峰值与形状等光谱特征;主要指标为特征峰波长,特征峰峰高,红外波段(1.28~25.00μm)、近红外波段(1.28~3.00μm)、ATP能量代谢特征波段(2.0~2.5μm)、人体红外辐射峰值波段(7.5~10.0μm)辐射强度。结果 碳化艾柱燃烧红外单光束光谱峰值位于4.012μm,普通艾柱(存储3年、叶绒比3∶1、中紧密度)峰值位于4.630μm;扣除大气背景辐射后,光谱均在4.241μm或15.000μm附近出现波峰或波谷。与普通艾柱(存储3年、叶绒比3∶1、中紧密度)比较,碳化艾柱红外波段辐射强度更高;特征峰波长更长;特征峰高度更低(P<0.05)。与存储3年艾柱比较,存储10年艾柱的红外波段、近红外波段、ATP能量代谢特征波段、人体红外辐射峰值波段辐射强度更高(P<0.05);存储5年艾柱的ATP能量代谢特征波段辐射强度更高(P<0.05)。与存储5年艾柱比较,存储10年艾柱的红外波段、近红外波段、ATP能量代谢特征波段、人体红外辐射峰值波段辐射强度更高(P<0.05)。与叶绒比3∶1艾柱比较,叶绒比10∶1艾柱的红外波段、近红外波段、ATP能量代谢特征波段、人体红外辐射峰值波段辐射强度更高(P<0.05);叶绒比5∶1艾柱的红外波段、ATP能量代谢特征波段、人体红外辐射峰值波段辐射强度更高(P<0.05)。与低紧密度艾柱比较,中、高紧密度艾柱的红外波段、人体红外辐射峰值波段辐射强度更高(P<0.05)。结论 碳化艾柱辐射强度较强,但其光谱异于普通艾柱,增加普通艾柱的存储年份及叶绒比可以加强艾柱辐射强度,且紧密度适中的普通艾柱更优,为传统艾灸的作用机制研究提供基础。

烟叶打叶后大片率调控关键技术研究

为解决当前烟叶打叶后大片率过高的问题,提出了对打叶后烟片采用振筛机大片叶筛选、图像监控打辊机可控再打叶的技术处理方案。设计实现了烟片分选再处理装置,并通过实验研究了不同控制参数对再打叶后烟叶的影响。结果表明:(1)提高振筛机筛孔孔径有助于大片叶分离;(2)再处理打辊机框栏开口尺寸与形状相比提高转速对再打叶效果的影响更为显著,使用圆形50.8 mm框栏开口的打辊机可实现再打叶后大片率低于30%、中片率高于45%、含末率低于0.3%的水平;(3)提高打辊机转动频率和增加再处理大片叶分料比例有助于降低大片率,但均会导致中片率降低和烟末增加。实验表明打辊机转动频率和分料比例分别控制在40 Hz和50%左右时表现较好。

新疆地区4个红豆草新品系的生产性能评价

【目的】为客观评价红豆草新品系的生产性能,为新品系的示范推广及品种审定提供基础数据。【方法】试验以新疆农业大学选育的3个红豆草新品系ND056-1、ND056-2、ND056-3为材料,以奇台红豆草为对照(CK),通过观测生育期、株高、干鲜比、茎叶比、鲜草产量、干草产量等指标,对其生产性能进行综合评价。【结果】研究结果表明,四个材料的物候期无差异,ND056-3的平均株高最高为104.2 cm,ND056-2的次之为104.13 cm,CK最低为103.07 cm;ND056-1的干鲜比最高为30.15%,是对照的1.22倍,ND056-2最低为23.73%,是对照的0.96倍;ND056-3的叶茎比最高(1.2266),ND056-2次之(0.9918),分别是对照的1.1倍和1.38倍;全年鲜草产量中,ND056-3的最高为70.58 t/hm^(2),ND056-1次之为66.25 t/hm^(2),分别是对照的1.247倍和1.170倍;全年干草产量中,ND056-1的最高为19.89 t/hm^(2),ND056-3次之为19.32 t/hm^(2),分别是对照的1.30倍和1.27倍。【结论】综合分析认为,新品系ND056-3适合作为青鲜草利用,ND056-1适合作为干草利用。

不同相思人工林叶片养分化学计量的内稳性特征

于2018年7月在福建省漳浦县中西国有林场,以厚荚相思(Acacia crassicarpa A.Cunn.ex Benth.)、黑木相思(A.melanoxylon R.Br.)、卷荚相思(A.cincinnata F.Muell.)、直干大叶相思(A.auriculiformis A.Cunn.ex Benth.)和马占相思(A.mangium Willd.)为研究对象,研究其成熟叶片N、P、K及其C∶N、C∶P、N∶P的内稳性特征,以期揭示不同相思树种对环境的生态适应策略。结果表明:不同相思树种叶片各元素内稳性指数存在差异,除黑木相思N的内稳性指数为弱稳态型外,其它4种相思HN均属于敏感型,5种相思P和K的内稳性指数均为敏感型;元素化学计量比的内稳性指数明显高于元素含量,相思树种C∶N内稳性指数均为稳态型,相思树种HC∶P、HC∶K和HN∶P普遍表现为弱稳态或稳态型(直干大叶相思HC∶P、卷荚相思HC∶K和马占相思HN∶P除外)。总之,厚荚相思具有较高的HC∶P和HC∶K,黑木相思具有较高的HN和HN∶P,卷荚相思具有较高的HP和HC∶N,说明不同相思树种对外界环境的适应能力不同,较高内稳性的相思物种对相应土壤养分变异的适应能力更强。

煤矿复垦区博落回生物量及其分配特征对氮的响应

为探究博落回(Macleaya cordata)在不同施氮梯度下各生育期生物量及总生物量分配的动态变化规律,设置5个施氮水平:CK(0 kg·hm^(−2))、N_(1)(75 kg·hm^(−2))、N_(2)(150 kg·hm^(−2))、N_(3)(225 kg·hm^(−2))、N_(4)(300 kg·hm^(−2)),从2020年起开展为期两年的连续施氮试验,揭示博落回在贫瘠土壤中的生长适应特征。结果表明:1)N_(3)、N_(4)各时期博落回的冠生物量、根系生物量和总生物量均显著高于CK、N_(1)和N_(2)(P<0.05)。2)博落回的根冠比在不同年份有差异,第1年所有处理的根冠比在6月最低,分别为0.04、0.12、0.09、0.15和0.16,第2年在8月最低,分别为0.20、0.18、0.08、0.06和0.10;2021年6月和8月,CK的根冠比都高于其他处理。3)2020年10月N_(3)的茎叶比显著高于其他处理(P<0.05),其他处理的茎叶比各月份间差异不大;2021年各处理间茎叶比随恢复时间逐渐增加,在11月达到最大,分别为2.82、1.19、1.23、1.89和2.05。综上所述,建议对煤矿复垦区博落回施加225~300 kg·hm^(−2)的氮,以此来促进博落回在贫瘠土壤中的快速定植,本研究可以为缺氮土壤中博落回的生长适应性研究提供理论依据。

不同叶果比对沃柑果实分级和养分分配的影响

研究不同叶果比对沃柑果实分级和养分分配的影响,筛选沃柑在栽培中最适合的叶果比。通过进行疏果处理,调查不同叶果比条件下不同分级果实个数和产量,分析相关性;研究叶片和果实中大量营养元素差异特征,并分析沃柑周年营养变化特征。结果表明,沃柑叶果比与株产量、果实个数呈负相关,与平均果径和70~80及80 mm以上果实比例呈正相关。当叶果比在30~40时,70~80及80 mm以上果实比例最高,沃柑最适叶果比为30~40。在膨果期,当叶果比为15、30、60时,叶片中的全氮含量显著高于果实;叶果比为60时,果实中全磷含量高于叶片;叶果比为30和60时,果实中的全钾含量高于叶片。此外,沃柑中大量营养元素在果实膨大初期5—7月的含量最高。综合比较认为,栽培中沃柑最适宜的叶果比为30~40,沃柑大量营养管理时主要在膨果期对树体提供充足的养分。该研究为广西地区沃柑栽培中重要园艺疏花疏果和营养管理提供重要的数据支持。

新疆地区4个红三叶新品系的生产性能评价

【目的】旨在客观评价红三叶新品系的生产性能,为新品系的示范推广及品种审定提供基础数据。【方法】以新疆农业大学选育的3个红三叶新品系(HSY6、HSY11、HSY12)为研究对象,以蒙农1号红三叶(TrifoliumpratenseL.cv.MengnongNo.1)为对照(CK),通过观测生育期、株高、干鲜比、茎叶比、鲜草产量、干草产量等指标,对其生产性能进行综合评价。【结果】研究结果表明,4份材料的物候期无显著差异;HSY12的平均株高最高,为70.52 cm,CK的次之,为68.87 cm,HSY6最低,仅为64.77cm;HSY11的干鲜比最高,为20.16%,是对照的1.03倍;HSY6的叶茎比最高(0.9427),HSY11的次之(0.8834),分别是对照的1.17倍和1.05倍;全年(三茬)鲜草产量中,HSY11的最高,为130.70 t/hm^(2),CK的次之,为120.93 t/hm^(2);全年(三茬)干草产量中,HSY11的最高,为26.80t/hm^(2),CK次之,为23.30t/hm^(2)。【结论】综合分析认为,与其他3份材料相比,新品系HSY11更适合作为青鲜草和干草利用。

不同温度下杉木凋落叶分解过程中碳氮磷释放及其化学计量比变化

[目的]研究升温对不同发育阶段杉木凋落叶分解过程中碳(C)、氮(N)、磷(P)释放规律及其生态化学计量特征的影响,揭示气候变暖背景下杉木人工林凋落叶分解过程中养分释放特征。[方法]收集中龄林(18年生)、成熟林(30年生)和过熟林(42年生)3个发育阶段的杉木凋落叶,设置25、30和35℃3个温度梯度进行室内模拟分解试验。[结果](1)在264 d的分解周期内,各发育阶段杉木凋落叶C、N、P残留率总体表现为随分解时间的增加而减小,但不同元素残留率变化模式不同,C残留率表现为释放—富集—释放模式,N残留率表现为富集—释放模式,P残留率表现为释放—富集模式。(2)拟合模型结果表明,成熟林与过熟林凋落叶分解过程中N周转期在35℃处理下比25℃处理分别缩短了34.4%和16.9%,P周转期分别缩短了38.4%和43.8%。(3)不同发育阶段杉木凋落叶分解过程中C:N、N:P比总体呈波动变化,C:P比呈先增大后减小的变化趋势,杉木凋落叶C:N、C:P、N:P比变幅分别为9.32~39.0、949~2194、32.7~153,升温处理在凋落叶分解过程总体上增大了C:P、N:P,降低了C:N比。[结论]温度升高能够缩短成熟林、过熟林凋落叶分解过程中N、P的周转期,提高各发育阶段杉木凋落叶分解过程中的C:P、N:P,说明杉木凋落叶分解明显受P限制,建议根据不同发育阶段杉木的生长需求,适当增加磷肥的施用。

3个紫花苜蓿新品系在新疆维吾尔自治区的生产性能评价

[目的]评价3个紫花苜蓿新品系在新疆维吾尔自治区的生产性能。[方法]以新疆农业大学草种质资源与育种团队选育的3个紫花苜蓿新品系MX01、MX02、MX03作为研究对象,以新疆维吾尔自治区培育的紫花苜蓿本地品种“新牧4号”作为对照(CK),测定并比较不同紫花苜蓿材料在3个刈割茬次下的株高、干鲜比、叶茎比、鲜草产量、鲜草总产量、干草产量、干草总产量,并对各性状指标与鲜草总产量和干草总产量之间的相关性进行分析。[结果]4份材料的平均株高从高到低依次为MX01(95.23 cm)、CK(94.56 cm)、MX03(90.25 cm)、MX02(88.36 cm),表明MX01的生长速度较快。4份材料的平均干鲜比从高到低依次为MX02(32.22%)、CK(28.81%)、MX01(27.76%)、MX03(25.36%),表明MX02在干物质积累方面的表现较好。4份材料的平均叶茎比从高到低依次为MX03(70.85%)、MX02(67.53%)、CK(66.68%)、MX01(62.76%),表明MX03在品质方面具有优势。MX02和MX03前2个刈割茬次的鲜草产量对鲜草总产量的贡献率较高,均达到80%以上;4份材料的鲜草总产量从高到低依次为MX03(89.01 t/hm^(2))、MX02(86.33 t/hm^(2))、CK(83.53 t/hm^(2))、MX01(76.62 t/hm^(2)),MX03的鲜草总产量显著(P<0.05)高于其他3份材料,提示该份材料适宜用作鲜草生产。3个紫花苜蓿新品系材料在3个刈割茬下干草产量对干草总产量的贡献率变化存在明显差异;4份材料的干草总产量从高到低依次为MX02(27.82 t/hm^(2))、CK(24.06 t/hm^(2))、MX03(22.57 t/hm^(2))、MX01(21.27 t/hm^(2)),提示MX02适宜用作干草生产。第2茬鲜草产量与鲜草总产量呈极显著(P<0.01)正相关,第2茬叶茎比与干草总产量呈极显著(P<0.01)负相关。[结论]对不同刈割茬次及整个生产周期下3个紫花苜蓿新品系多项性状指标的评价结果表明,新品系MX02和MX03的综合表现更好,具有在新疆维吾尔自治区推广种植的潜力。

基于不同茎叶比的仙鹤草配方颗粒研究

目的:建立一个仙鹤草配方颗粒指标性含量数据筛选的方法。方法:基于仙鹤草茎、叶在黄酮类与鞣花酸的含量差异,以仙鹤草标准汤剂中茎叶比例为横坐标、黄酮/鞣花酸含量比为纵坐标建立仙鹤草标准汤剂所用饮片茎叶比例预测模型,并结合仙鹤草药材自然环境生长状况下茎/叶比例对数据进行筛选,确定入选用于仙鹤草配方颗粒指标性含量制定的仙鹤草标准汤剂参照数据。结果:通过对数据的筛选,确定了仙鹤草标准汤剂槲皮苷的含量范围为1.33~2.47 mg/g,鞣花酸的含量范围为1.35~2.50 mg/g。结论:建立的黄酮/鞣花酸含量比的方法可预测仙鹤草配方颗粒所用饮片的茎叶比例,利用茎/叶比例对仙鹤草标准汤剂指标性含量数据进行筛选,所得范围较筛选前明显缩窄,以此制定的指标性含量限度范围可有效地保证生产的中药配方颗粒与临床所用饮片的一致性。

商用车复合式前空悬钢板弹簧设计优化

为了解决复合式前空悬钢板弹簧可靠性验证过程中出现的断裂问题,文章从四个方面对原方案进行优化:第一,提高材料极限应力,采用代号为LQSP1300的材料,屈服强度由原来的1100 MPa提升到1300 MPa。第二,局部结构优化,第二片后段加长20 mm,改善钢板弹簧第一片板簧作用时应力集中。第三,优化钢板弹簧弧高,在标定高度下,钢板弹簧反向承载,使其在上跳过程中工作应力呈先减小后增加的趋势,提高疲劳寿命。第四,钢板弹簧喷丸工艺优化,上下表面均进行喷丸处理,形成残余应力层,使钢板弹簧在上下跳动变形的过程中均可以抵消一部分应力,提高疲劳寿命。通过四个方面的优化,新方案台架疲劳试验次数提升45.4%,同时通过了12000 km道路可靠性试验。

三江源区适宜的小黑麦和饲用豌豆混播比例及施肥方法

【目的】三江源区地处青藏高原,是中国母亲河的发源地,也是牦牛等典型牲畜的重要草场。探索适宜的施肥方法和牧草作物混播比例,旨在提高牧草产量,减轻生态重要地区天然草场的放牧压力。【方法】于2022年在三江源地区进行了小黑麦和饲用豌豆的田间试验,试验材料为小黑麦品种‘青饲麦1号’和饲用豌豆品种‘青建1号’。设置3个施肥处理:不施肥(A_(1))、单施氮肥(尿素75 kg/hm^(2),A_(2))、氮磷配合施用(尿素75 kg/hm^(2)和过磷酸钙300 kg/hm^(2),A3);每个施肥处理下,分别设小黑麦和豌豆混合播种比例70∶30(B1)、50∶50(B_(2))和30∶70(B_3)。在豌豆盛花期刈割前,调查小黑麦和饲用豌豆株高、叶片形态指标(面积、周长、长度、宽度),及生物量和营养品质。【结果】与不施肥处理A_(1)相比,施肥处理(A_(2)和A_3)显著提高了牧草的鲜重和干重、蛋白质产量以及两种作物的株高和叶面积。A_(2)和A_3处理在上述指标上没有显著差异,但A_3处理叶宽的增幅显著高于A_(2)。A_(2)和A_3处理对两种牧草粗蛋白、可溶性糖、中性和酸性洗涤纤维含量均无显著影响,但A_(2)处理增加了粗脂肪含量。小黑麦和饲用豌豆的播种比例对两种作物的鲜重、干重、蛋白质产量和株高没有显著影响,但降低小黑麦播种比例增加了饲草粗脂肪和可溶性糖含量,显著降低了中性与酸性洗涤纤维含量。播种比例与施肥有显著的交互作用,A_3B_(1)的牧草鲜重和干重最高,分别比其他处理高36.09%~180.08%和62.27%~281.59%,叶面积和蛋白质、可溶性糖含量也最高。A_3B_(1)处理的小黑麦叶片周长比A_(1)B_(1)、A_(1)B_(2)和A1B3处理分别高15.76%、40.29%和54.51%,饲用豌豆叶面积比A1B1、A1B2和A1B3处理分别提高20.31%、14.06%和64.65%,饲草中性洗涤纤维含量分别比A1B1、A1B2和A1B3处理增加了7.15%、27.14%和17.89%。【结论】氮磷配施可显著提高牧草生产性能、叶片形态和牧草质量。小黑麦和饲用豌豆按70∶30的比例混合播种,牧草生产性能、叶片形态和质量均优于其他处理。因此,在高寒地区,建议推广小黑麦和饲用豌豆按70∶30的比例混合播种,并配施氮、磷肥。

打浆度及浆网速变化对造纸法再造烟叶片基成形匀度的影响研究

【目的】研究再造烟叶浆料打浆度及浆网速比对再造烟叶片基匀度的影响,为再造烟叶生产提供依据。【方法】采用小型长网抄造试验纸机以不同打浆度的再造烟叶浆料在不同的浆网速条件下抄造再造烟叶片基,利用匀度仪对片基的匀度进行测定,同时检测片基的松厚度、透气度和抗张强度等指标。【结果】(1)随着浆料纤维打浆度升高,不同浆网速比下成形的片基匀度标准偏差均下降,片基成形匀度提高;(2)片基成形匀度较好的浆网速比可设定在0.95左右;(3)随着浆料纤维打浆度升高,不同浆网速比下成形的片基MD纵向抗张强度及CD横向抗张强度均升高;当浆料打浆度不变时,随着浆网速比升高,MD纵向抗张强度降低,CD横向抗张强度升高,而厚度、透气度变化不显著;(4)随着浆网速比的增大,不同浆料打浆度下成形的片基MD/CD抗张强度比值均下降;随着浆料纤维打浆度升高,片基MD/CD抗张强度比值逐渐下降,且浆网速比越小,下降越大;(5)随着浆料纤维打浆度升高,成形片基的厚度逐渐下降;(6)随着浆料纤维打浆度升高,成形片基的透气度逐渐下降;(7)浆料打浆度对片基匀度、MD纵向抗张强度、CD横向抗张强度、厚度、透气度的影响大于浆网速比对以上物理指标的影响。

Basal internode elongation of rice as affected by light intensity and leaf area

Short basal internodes are important for lodging resistance of rice(Oryza sativa L.).Several canopy indices affect the elongation of basal internodes,but uncertainty as to the key factors determining elongation of basal internodes persists.The objectives of this study were(1)to identify key factors affecting the elongation of basal internodes and(2)to establish a quantitative relationship between basal internode length and canopy indices.An inbred rice cultivar,Yinjingruanzhan,was grown in two split-plot field experiments with three N rates(0,75,and 150 kg N ha−1 in early season and 0,90,and 180 kg N ha−1 in late season)as main plots,three seedling densities(16.7,75.0,and 187.5 seedlings m−2)as subplots,and three replications in the 2015 early and late seasons in Guangzhou,China.Light intensity at base of canopy(Lb),light quality as determined from red/far-red light ratio(R/FR),light transmission ratio(LTR),leaf area index(LAI),leaf N concentration(NLV)and final length of second internode(counted from soil surface upward)(FIL)were recorded.Higher N rate and seedling density resulted in significantly longer FIL.FIL was negatively correlated with Lb,LTR,and R/FR(P<0.01)and positively correlated with LAI(P<0.01),but not correlated with NLV(P>0.05).Stepwise linear regression analysis showed that FIL was strongly associated with Lb and LAI(R2=0.82).Heavy N application to pot-grown rice at the beginning of first internode elongation did not change FIL.We conclude that FIL is determined mainly by Lb and LAI at jointing stage.NLV has no direct effect on the elongation of basal internodes.N application indirectly affects FIL by changing LAI and light conditions in the rice canopy.Reducing LAI and improving canopy light transmission at jointing stage can shorten the basal internodes and increase the lodging resistance of rice.