根区氮钾水平对杂交和常规水稻品种光合作用及根系生长的影响

Root box experiments were conducted to evaluate the effects of N and NK levels in the root zone on shoot photosynthesis and root growth of hybrid an cultivar of rice (Oryza sativa L.) on two paddy soils (clayey and silty).The results showed that dry matter yields in the hybrid and the cultivar were considerably increased by NK supply,bu the effect was greater for the hybrid.Supply of NK in the root zone significantly increased photosynthetic rate of the lower position leaf and the active green leaf area per plant,in which the effects were much more obvious in the hybrid rice than in the cultivar.High NK supply in the root zone stimulated the root growth,and decreased pH and increased the oxidation zone in the rhizosphere in both entries,but to a greater extent in the hybrid .The results indicated that higher NK levels were needed to maintain higher root activity and shoot photosynthetic capacity in rice,particularly in hybrid rice.     

川西平原小麦氮营养快速诊断及氮追推荐研究

在温江县天府镇进行田间试验,研究了二苯胺法和反射仪法快速诊断小麦氮营养的可行性,并探讨了小麦缺氮诊断指标和氮追肥推荐模型。结果表明,小麦拔节期茎基部ＮＯ３－Ｎ含量与氮肥用量显著相关快速测定植株体内ＮＯ３－Ｎ含量的二苯胺法和反射２仪法 能很好反映小麦的氮营养状况,且二者间有较好 ;小麦拔节期茎基部ＮＯ３－Ｎ含量临蚧二苯胺色阶为２．２０,反射仪值为１３００ｍｇｋｇ;试验也发现在本区严重缺氮条件下北方地     

氮及相关的酶活性对小麦根际施肥的反应

In the present experiment,wheat seedlings(Trticucum aestivum L.)were grown on a purple soil with various fertilizer treatments in order to investigate the responses of nitrogen and related enzyme activities in the rhizosphere,The results revealed the increments of both organic matter and total N in the soil with the proximity to the growing roots,especially in treatment of supplying pig manure in combination with chemical fertilizer,suggesting that they could ome from root and microorganism exudation which could be intensified by inorganic-organic fertiliztion,being of benefit to improving the physical and bilogical envi-ronment in the rhizosphere of wheat.Much more inorganic N was observed in the fertilized soils surrounding wheat roots than in the CK treatment ,indicating ,the improvement of crop N supply in the rhizosphere of wheat by fertilization. The activities of invertase,urease and protease in the root zone were greatly enhanced as compared to those in the other parts of soil except that the urease activities were similar in the rhizospher and nonrhi-zosphere of the CK and pig manure treatments,indicating that invertase and protese could be produced by growing roots and rhizosphere microorganisms,in contrast to urease which could be stimulated by urea,Also,significant increment of chemical fertilizer combined with pig manure,suggested that fertilization not only accelerated the renewal of organic matter bu also enhanced bioavailability of organic N in that soil zone .This could be the reason why the total amount of inorganic N available for plants was increased more obviously in the rhizosphere of wheat of the fertilizaton treatments than in taht of the CK treatment.     

不同施氮水平下增铵营养对小麦生长和氮素利用的影响

采用盆栽试验,研究了不同施氮水平下小麦生长、氮素积累对不同形态氮营养的反应差异。结果表明,中氮水平下增铵营养(NH4NO3+DCD)处理的小麦生长具有明显的优势,表现为干物重、氮积累量增加,单株叶面积提高、硝酸还原酶活性较高,最终子粒产量最高。氮形态对生育早期植株的形态特征、开花期旗叶光合速率及成熟期器官内物质分配比例的影响较小。低氮和高氮下增铵营养不同程度地抑制了小麦生长,降低了氮素利用效率。增铵营养显著减少了土壤中的氮淋溶,但氮淋溶量受施氮量的影响更为显著。     

间作系统氮调控对小麦氮钾营养及条锈病发生的影响

通过探讨间作和施氮对小麦植株氮钾养分吸收、分配及条锈病发生的影响,明确氮钾养分吸收和分配与小麦条锈病发生的关系,以期为合理施肥实现控病增产提供理论依据。在云南安宁和峨山两地布置田间小区试验,研究3种施氮水平(0 kg×hm~(–2)、90 kg×hm~(–2)和180 kg×hm~(–2))和2种种植模式(小麦单作、小麦||蚕豆间作)对小麦植株氮钾含量与分配以及小麦条锈病发病率及病情指数的影响。结果表明,施氮增加了小麦产量,且间作增产效应显著;与单作相比,间作小麦平均显著增产31.9%(安宁)和18.0%(峨山);小麦||蚕豆间作产量优势明显,土地当量比为1.20～1.37(安宁)和1.16～1.27(峨山),但间作增产优势随施氮量增加而降低。施氮在提高产量的同时也加重了小麦条锈病危害,随施氮量增加,单、间作小麦条锈病的发病率和病情指数均呈增加趋势。间作有较好的控病效果,与单作相比,间作小麦发病率、病情指数分别显著降低9.6%～22.0%、23.7%～33.7%(安宁)和29.5%～36.5%、29.3%～39.6%(峨山)。施氮增加了小麦植株氮含量,且主要累积在叶片,叶片氮含量占氮吸收总量的41.3%～47.4%(安宁)和35.9%～44.1%(峨山);但间作显著降低小麦植株氮含量,并显著提高钾含量,因而显著降低了叶片氮/钾比。相关性分析表明,小麦条锈病发病率和病情指数与植株氮含量、叶片氮/钾比呈显著正相关,与钾含量呈极显著负相关。施氮增加了小麦植株氮含量,提高了叶片氮/钾比,进而加剧小麦条锈病发生;而间作则通过增加钾含量,降低小麦植株氮含量及叶片氮/钾比,平衡小麦植株内氮钾养分而增强小麦对条锈病的抗性。     

氮钾营养对面包强筋小麦产量和品质的影响

采用田间试验研究N、K不同用量及其配比对龙94-4083强筋小麦产量及品质的影响。结果表明,不同N、K营养对小麦产量、养分吸收及其构成和品质有明显的影响。适宜的N、K配比及用量可提高小麦干重、有效穗数、穗长、穗粒数、千粒重,提高小麦植株对N、P、K养分的吸收。小麦产量及其构成均表现出随N、K用量的增加而增加的趋势。所有处理中以N112.5K75处理获得了最高的产量。品质分析结果显示,小麦子粒粗蛋白、湿面筋、沉降值和稳定时间均表现出随N、K用量的提高而增加的趋势。全部处理中以N112.5K75处理获得了较高的沉降值、粗蛋白和湿面筋含量及较长的稳定时间。N、K用量及其配比适宜既能提高小麦产量,又能改善小麦品质。     

豫东潮土氮钾营养对强筋小麦干物质积累和产量的影响

在豫东潮土区壤质土壤上,研究了在施用磷肥的基础上,施用氮肥和钾肥对强筋小麦干物质积累量、小麦产量的影响.结果表明,增施氮肥和钾肥都可以提高小麦干物质积累量,尤其在拔节至抽穗期单株干物质积累速度最快;N用量为282.5kg·hm-2,K2O用量为270kg·hm-2时更有利于强筋小麦抽穗期对养分的需求;从产量上看,N 180～270 kg·hm-2,K2O 225～300 kg·hm-2为合适施肥量.     

施氮量对四川盆地小麦生长及灌浆的影响

【目的】施氮量对小麦光合产物的积累、转运和分配影响明显,氮肥运筹是调控小麦物质生产的重要手段。为进一步发挥四川盆地小麦的增产潜力,2011~2013年,在四川省江油市开展了施氮量对两个高产小麦品种物质生产及灌浆特性影响的研究。【方法】试验采用裂区设计,品种为主区,施氮量为副区,参数品种为内麦836和川麦104,施氮(N)水平分别为0、90、135、180、225 kg/hm2,在小麦生长期间和收获后分别测试了个体和群体生物量、产量、产量结构和灌浆参数。【结果】施氮量、品种以及年际间气候条件均对产量、产量结构以及干物质积累量、叶面积指数有明显影响,两因素或三因素互作效应因指标不同而异。同一施氮水平下,川麦104的籽粒产量高于内麦836,氮空白区内麦836平均产量6638.9 kg/hm2,川麦104为6717.7 kg/hm2。135 kg/hm2施氮水平下,两个品种的生物产量和籽粒产量分别超过18000和9000 kg/hm2,与180 kg/hm2和225 kg/hm2处理差异不显著。两个品种产量与施氮量之间的关系符合一元二次函数关系(P0.05),川麦104 y=-0.1056x2+44.023x+6724.6,内麦836 y=-0.0934x2+35.991x+6651.5,理论最高产量以及最高产量施氮量川麦104均高于内麦836。增加施氮量利于各生育期干物质积累量的增加,但在135~225 kg/hm2施氮范围变幅较小,且135 kg/hm2处理在花后物质积累量更多。随着施氮量的增加,花前贮存物质对产量的贡献率呈先降低后升高的趋势,135kg/hm2处理的产量形成更多的依靠花后物质生产。增施氮肥虽然可促进公顷穗数和穗粒数的增加,但平均灌浆速率下降,内麦836最大灌浆速率在施氮量达到N 180 kg/hm2,川麦104在施氮量达到N 225 kg/hm2时即有大幅下降,千粒重也随之有不同程度的降低。【结论】花后干物质积累量的差异是两个品种对氮肥响应出现差异的重要原因。在目前生产条件下,稻茬小麦高产施氮量在N 135~150 kg/hm2,即可确保小麦的产量,又可提高花前群体质量和花后物质生产量及转运效率。因此,在土壤肥力高、保水保肥力强的四川盆地,施氮量为135~150 kg/hm2可提升该地小麦的生产效益。     

Nitrogen and genotype effects on root growth and root survivorship of spring wheat

The nitrogen (N) fertilization of wheat (Triticum aestivum L.) is important for stable and high grain yield. However, the effect of N on root growth and survivorship is poorly understood. The objectives of this study were (1) to determine the effect of varying N availability on the growth and survivorship of roots and (2) to determine whether genotypic variation in N‐related traits are linked to root growth and survivorship. In a two‐year study, two spring wheat cultivars (Albis and Toronit) and an experimental line (L94491) were grown under low (20 kg N ha^–1) and high N supply (270 kg N ha^–1) in lysimeters equipped with minirhizotrons. The genotypes showed significant differences in N‐related traits: total shoot N content, grain N yield, N harvest index, and rate of decline in flag‐leaf greenness. However, there were relatively weak and inconsistent genotypic effects on the time course of root density, root growth during grain filling, and root survivorship. The level of N supply was the factor that most influenced the establishment, growth, and survivorship of roots; the high N supply, depending on the year and genotype, increased growth and survivorship of roots from 0% to 68% and 24% to 34%, respectively.     

控释氮肥对杂交水稻生育后期根系形态生理特征和衰老的影响

采用微区和小区试验的方法,研究了控释氮肥对杂交水稻生育后期根系形态生理特征及对根系衰老过程中膜脂过氧化产物和活性氧清除酶活性的影响。研究表明,施用控释氮肥,明显地增加杂交水稻生育后期的根干重、根长和根长密度,而根半径减小;提高根系活力和吸收面积,使杂交水稻生育后期根系中MDA含量降低和SOD、POD和CAT的活性提高。控释氮肥中,氮的逐渐释放,可减少具有强烈伤害的活性氧产物速率及其累积数量,提高活性氧清除酶的活性,在很大程度上延缓了杂交水稻生育后期根系的衰老和吸氮能力的衰退。     

不同氮、磷用量对杂种小麦旗叶光合特性的影响

在大田条件下研究了不同氮、磷用量对杂种小麦旗叶光合特性的影响。结果表明,在施N122.5～337.5kg/hm2,P2O590～270kg/hm2范围内,随肥料用量增加杂种小麦旗叶净光合速率(Pn)、叶绿素(Chl)含量、可溶蛋白(Pro)含量、气孔导度(gs)和叶肉导度(gm)均升高,光合功能期延长,叶源量增加。母本(C6-38)与杂种F1表现相同趋势,而父本(Py85-1)在中肥和高肥处理下各指标的表现与杂种小麦相反。在旗叶整个老化过程中,杂种小麦与双亲本均值相比的净光合速率和光合功能期的平均优势均随氮、磷用量的增加而增大,且各施肥水平下均以老化后期大于前、中期。     

有机肥对小麦根系生长及根系衰老进程的影响

采用土柱栽培与室内分析相结合的方法,研究了有机肥对小麦根系生长及根系衰老进程的影响。结果表明,有机肥可促进小麦根系的生长和根系在深层土壤中的分布,使小麦根系的总鲜重和深层土壤根系鲜重明显增加;提高不同土层、特别是深层土壤中根系的活力,使小麦生长后期保持较高的根系吸收养分的能力。有机肥可促进根系对氮、磷、钾的吸收和向子粒中的转移,使氮、磷、钾在子粒中的分配量增加;而且能抑制根系的膜脂过氧化作用,使不同土层小麦根系SOD活性提高、MDA含量降低,从而延缓了根系的衰老。     

小麦生长期土壤养分与根系活力变化及其相关性研究

研究了小麦生长期内土壤氮、钾与小麦根系活力变化及其相关性。结果表明,土壤碱解氮、速效钾和非交换性钾含量随小麦生育进程呈现有规律的变化;小麦根系活力呈现先增加,孕穗期峰值出现后迅速下降,成熟时根系活力下降到最低值的变化规律,不同施肥处理小麦整个生育期内根系活力大小顺序为:MNPK、NPK>NK>N、NP>CK、M。土壤碱解氮、速效钾、非交换性钾含量与小麦根系活力呈显著或极显著正相关,说明土壤N、K养分有效性的高低是影响小麦根系活力的重要因素。     

不同土壤水分条件下施磷量对小麦旗叶衰老及产量的影响

在防雨旱棚池栽条件下研究了水分胁迫(W1)和水分适宜(W2)条件下不同施磷量对小麦旗叶衰老及产量的影响.结果表明,小麦开花后,W1水平下,施磷150 kg/hm~2处理的超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)下降幅度及丙二醛(MDA)上升幅度较其他处理小;W2水平下,随施磷量的增加,SOD、POD和CAT活性增加、MDA降低,可见水分胁迫下适宜的施磷量以及适宜的水分条件下增加施磷量均可以改善小麦体内的保护酶,增加小麦叶面积指数和旗叶叶绿素含量,提高光合速率,进而延缓衰老,提高产量.本试验条件下,虽然75%土壤田间持水量与施磷量150 kg/hm~2的处理组合达到了最高产量,但与55%土壤田间持水量与施磷量150 kg/hm~2的处理组合的产量差异不显著,综合观之,后者是最佳水肥处理组合.     

Sulfur affects root growth and improves nitrogen recovery and internal efficiency in wheat

Wheat plants were cultivated in pots with the objective of evaluating the effect of two sulfur (S) rates (+S and ?S) on (i) shoot growth, S and nitrogen (N) uptake and nitrogen use efficiency (NUE) and (ii) root growth and architecture and its relations with S and N uptake. Plant samplings were at Z39, Z51 and Z92 stages. Shoot mass and NUE were greater in +S treatment at the three stages. ?S treatment increased root growth at Z39 (14% more length and 16% more tips) in comparison with +S, but the opposite occurred at Z51 (31% less area and 42% less mass). S uptake per unit root mass, area and length were greater in +S treatment at Z39 and Z51. A similar pattern was determined for nitrogen uptake (Nu) at Z39, but the opposite occurred at Z51. This indicates that Nu is mainly controlled by shoot growth and not by root growth.     

不同氮效率玉米杂交种的根系生长、氮素吸收与产量形成

以氮效率不同的4个玉米杂交种(组合)为材料,在两个氮水平下分析了根系大小与氮素累积及产量形成方面的相互关系。结果表明,氮高效杂交种(NE1和ND108)吸氮量显著高于氮低效品种,但这种差异主要来自于吐丝后氮累积量,而在前期不同基因型间氮素累积差异不显著。两个氮水平下,氮高效品种NE1和ND108都具有较大的根系;在不施氮条件下,氮低效品种209115的根系干重与ND108相近,而其氮累积量及产量均最低。说明根系大小是决定氮累积量的主导因素,但氮吸收速率的作用也不可忽视。     

秸秆覆盖与氮肥运筹对杂交稻根系生长及氮素利用的影响

【目的】在我国稻-麦、稻-油等多熟制区域,富含氮素的小麦、油菜等水稻前茬作物秸秆被大量弃置、焚烧,造成极大浪费和环境污染,与此同时,稻季氮肥投入量却在逐年增加,因此在水稻生产中研究秸秆覆盖与氮肥配合施用的理论与技术,对实现秸秆还田与减少氮肥用量具有重要意义。本试验研究油菜、小麦2种秸秆覆盖方式下,3种不同的氮肥运筹方式对杂交稻主要生育时期根系生长、氮素吸收利用特征及产量的影响,并探讨其根系生长与氮素利用及产量间的关系,以期寻求最佳的秸秆还田与氮肥运筹搭配模式。【方法】本试验以杂交稻F优498为材料,采用两因素裂区试验设计,主区为小麦秸秆覆盖(S1)、油菜秸秆覆盖(S2)和无秸秆覆盖(S0);副区为氮肥运筹模式,在135 kg/hm2总施氮量条件下,设置基肥∶蘖肥∶穗肥为5∶3∶2(N1);基肥∶蘖肥∶穗肥为3∶3∶4(N2);基肥∶蘖肥∶穗肥为3∶1∶6(N3)3种氮肥运筹模式,以不施氮肥(N0)为对照。研究各处理杂交稻在移栽后20 d、移栽后30 d、齐穗期和成熟期根系生长及形态、各生育期的干物质与氮素积累,水稻茎鞘的干物质转运、产量及其构成因子以及各时期氮素积累及利用效率,同时对各生育时期根系生长与氮素利用及产量间的关系进行分析。【结果】结果表明,小麦秸秆覆盖均可有效促进杂交稻各生育时期的根系生长、改善根系形态、增加各时期的干物质与氮素积累,提高氮肥的利用效率及稻米产量。在不同种类秸秆覆盖下,基肥∶蘖肥∶穗肥(倒4叶龄期施入)为3∶3∶4(N2)时,可及时地对杂交水稻主要生育时期的根系生长进行调控,有效促进抽穗至成熟期的干物质积累与转运率,提高水稻主要生育时期的氮素积累及氮肥利用效率,显著增加稻谷产量,为本试验中最优的氮肥管理模式;而氮肥后移比例过高(基肥∶分蘖肥∶穗肥运筹比例为3∶1∶6),会限制齐穗期根系的生长,导致稻谷产量及氮肥利用效率降低。相关性分析表明,秸秆覆盖与氮肥运筹下主要生育时期根干重、根体积、总根长与产量及氮素吸收利用均存在显著或极显著的正相关(r=0.38*0.78**),尤其以齐穗期的根体积与总根长、根干重与氮素累积、产量及氮素回收利用率的相关性最好。【结论】小麦秸秆、油菜秸秆覆盖能够有效促进杂交稻根系的生长,增加干物质与氮素积累,提高氮肥利用效率,且小麦秸秆覆盖效果更显著。秸秆覆盖条件下,氮肥运筹以基肥∶蘖肥∶穗肥为3∶3∶4时的水稻根系生长旺盛,物质生产能力强,氮肥利用效率最高。因此,小麦秸秆覆盖与基肥∶蘖肥∶穗肥以3∶3∶4的比例配合的水稻的产量最高,为最优组合。     

不同沟灌方式下根区水氮调控对棉花群体生理指标的影响

为探明水氮调控对沟灌棉花群体生长发育的影响机制,通过设置3种沟灌方式、3个灌水量和施氮量水平进行大田沟灌棉花试验研究,并利用高斯单峰分布模型模拟棉花群体生理指标变化趋势。试验结果表明：模型模拟精度相对较高。施氮处理下：与常规沟灌相比,交替隔沟灌低氮处理叶片光和势峰值下降39.3%,中氮处理各指标无显著差异,高氮处理下叶片光和势峰值提高17.26%,群体净同化率峰值下降21.69%;固定隔沟灌方式不同施氮处理各指标峰值下降35.1%～44.0%。灌水处理下：与常规沟灌相比交替隔沟灌低水分处理叶片光和势峰值下降23.94%,中等水分处理下叶片光和势提高13.63%,叶面积指数下降14.2%,高水分处理下各指标参数无显著差异;固定隔沟灌方式不同灌水处理各群体指标下降20.7%～47.22%。与常规沟灌棉花生物量和产量相比,交替隔沟灌各水氮处理地上干物质重和产量无显著差异,固定隔沟灌地上干物质重下降9.8%～19.3%,产量下降7.6%～8.9%。因此,交替隔沟灌的根区水、氮调控对棉花群体性能影响较显著,能够有效调控棉花群体生长发育,对于棉花水肥管理具有重要的应用价值。