氮高效利用基因型大麦的物质生产与氮素积累特性

通过土培盆栽试验,研究了22份大麦材料在低氮(125 mg·kg^-1)和正常氮(250 mg·kg^-1)处理下氮素吸收利用效率的基因型差异,探讨氮高效大麦干物质生产与氮素积累特性.结果表明： 大麦氮素吸收利用效率基因型差异显著.低氮处理下籽粒产量、氮素籽粒生产效率及氮素收获指数的最高值分别是最低值的2.87、2.92、2.47倍;氮高效基因型大麦籽粒产量、氮素籽粒生产效率和氮素收获指数均显著大于低效基因型,低氮处理下高效基因型3个参数较低效基因型分别高82.1%、61.5%和50.5%.氮高效基因型大麦各生育期干物质和氮素积累优势明显,干物质积累高峰出现在拔节-抽穗阶段,氮素积累高峰出现在拔节前;低氮处理下高效基因型典型材料DH61、DH121+的干物质量较低效基因型典型材料DH80分别高34.4%、38.3%,氮素积累量较DH80分别高54.8%、58.0%.供试大麦干物质和氮素的阶段性积累量对籽粒产量的影响为拔节前最大,且低氮处理下贡献率最高,分别为47.9%和54.7%;而干物质和氮素的阶段性积累量对氮素籽粒生产效率的影响在抽穗 成熟阶段最大,其次是播种-拔节阶段,低氮处理下这两个阶段的贡献率分别为29.5%、48.7%和29.0%、15.8%.氮高效基因型大麦在各生育期的物质生产和氮素积累能力强,低氮处理下优势较为明显,能够提高拔节前干物质生产和氮素积累能力,并协同提高大麦产量和氮素利用效率.     

A function for describing nitrogen uptake,dry matter production and rooting by wheat crops

The quantities,Y, of nitrogen taken up, and dry matter produced, at various times during the growth of six winter wheat crops at Rothamsted were shown to be related to thermal time,x, based on soil temperature, by a simple equation $$Y = (A^{ - 1/n} + \exp ( - kx))^{ - n} $$ whereA is the ultimate maximum ofY, n a shape factor andk a rate constant that is related toA andn throughx′, the inflexion point of the function. The value ofn was 1.5 for both N uptake and dry matter. The value ofA for N uptake,A _N , was well described by a multiple regression on sowing data,t _s , expressed as the number of days after August 31st, and rainfall,R _Apr , in the April before harvest, but no such regression could be found for the value ofA for dry matter,A _D . The rate constants,k _N andk _D , for N-uptake and dry-matter production respectively, could be related to the date of sowing and the weather through the corresponding inflexion points,x′ _N andx′ _D . Highly significant regressions were found, forx′ _N on the time,t _sf , between sowing and the return of the soil to field capacity and forx′ _D on the reciprocal oft _s . The function was used to generate N uptake curves from values ofA _N andk _N (obtained fromx′ _N ) given by inserting the appropriate values ofR _Apr ,t _s andt _sf in the regressions. These fitted measured N uptakes satisfactorily for the six crops used to obtain the regressions, and four grown subsequently, at Rothamsted, and also for six crops at Woburn. Values ofA _D had to be set arbitrarily because no regression had been found to predict them, but using these arbitrary values in the function gave dry matter curves that fitted the measurements satisfactorily for all ten Rothamsted crops and two of the Woburn crops. Tests for seasonal and site effects showed thatA _N was influenced more by differences between the two sites than by seasonal differences other than those inR _Apr , whereasA _D was strongly influenced by these seasonal differencess and very little by those between the sites.     

氮肥运筹对晚播冬小麦氮素和干物质积累与转运的影响

氮素平衡对干物质积累与分配的影响是农业生态系统研究的重要内容,在保障产量前提下减少氮肥施用量可减少环境污染与温室气体排放。以晚播冬小麦为研究对象,设置4个施氮量水平:0 kg/hm2(N0)、168.75 kg/hm2(N1)、225 kg/hm2(N2)、281.25 kg/hm2(N3),每个施氮量水平下设置2个追氮时期处理:拔节期(S1)、拔节期+开花期(S2),研究了氮肥运筹对晚播冬小麦氮素和干物质积累与转运及氮肥利用率的影响。结果表明:拔节期追施氮肥(S1)条件下,在225 kg/hm2(N2)基础上增施25%氮肥(N3)对开花期氮素积累总量和营养器官氮素转运量无显著影响;拔节期+开花期追施氮肥(S2)条件下,随施氮量增加,开花期氮素积累总量和花后营养器官氮素转运量升高;S2较S1显著提高成熟期籽粒及营养器官氮素积累量、花后籽粒氮素积累量及其对籽粒氮素积累的贡献率。同一施氮量条件下,S2较S1提高了成熟期的干物质积累量、开花至成熟阶段干物质积累强度和花后籽粒干物质积累量。同一追氮时期条件下,籽粒产量N2与N3无显著差异,氮肥偏生产力随施氮量增加而降低;同一施氮量条件下,S2较S1提高了晚播冬小麦的籽粒产量和氮肥吸收利用率。拔节期+开花期追施氮肥,总施氮量225kg/hm2为有利于实现晚播冬小麦高产和高效的最优氮肥运筹模式。     

水分亏缺和施氮对冬小麦生长及氮素吸收的影响

利用管栽试验研究了不同生育期,水分亏缺和施氮对冬小麦生长及氮素吸收的影响.结果表明：任何生育期水分亏缺都会影响冬小麦的株高、叶面积、干物质累积及对氮素的吸收.冬小麦对水分亏缺的敏感期为拔节期,其次为开花期、灌浆期和苗期.苗期干旱后复水对后期生长有显著的补偿效应,开花期适度干旱后复水对生物量形成和氮素吸收有一定的补偿作用,拔节期干旱对小麦的生长影响明显.相同氮肥处理下, 与不亏水处理比较, 苗期水分亏缺、拔节期水分亏缺、开花期水分亏缺、灌浆期水分亏缺的根系氮素积累量分别平均降低25.82%、55.68%、46.14%和16.34%,地上部氮素积累量分别平均降低33.37%、51.71%、27.01%和2.60%.在相同水分处理下冬小麦含氮量、累积吸收氮量都表现为高氮处理（0.3 g N·kg^-1FM）>中氮处理（0.2 g N·kg^-1FM）>低氮处理（0.1 g N·kg^-1FM）.水分逆境条件下施用氮肥对冬小麦植株生长和干物质累积及氮吸收具有明显的调节效应.     

氮对冬玉米干物质生产及生理特性的影响

通过对不同施氮水平下冬玉米的干物质生产及其生理特性的研究表明 :(1 )随着施氮量的提高 ,叶面积指数增大 ,叶片衰老延缓 ,花后保持有更大的叶面积持续期和光合势 ,有利于干物质的生产 ;(2 )施氮量的增加促进了花丝期前后植株各部分氮和干物质的累积 ,产量显著提高 ,但是营养体干物质和氮的转移率降低 ,尤其高氮条件下尚有大量干物质不能转移 ,库 /源比不协调 ,氮的生产力随之降低。     

水氮组合对冬小麦干物质及氮素积累和产量的影响

于2015—2017年小麦生长季在山东省泰安市农业科学研究院肥城试验基地进行田间试验,供试材料为‘泰山28',在150(A₁)、300(A₂)、450(A₃)、600 m³·hm^-2(A₄)4个灌水量和90(B₁)、135(B₂)、180(B₃)、225 kg·hm^-2(B₄)4个施氮水平下,研究水氮组合对小麦生长发育过程中干物质积累、氮素积累、水分消耗利用、光合特性、籽粒产量等的影响。结果表明: A₃B₃条件下各生育阶段的干物质积累量和氮素积累量,成熟期籽粒干物质和氮素积累量均为最大,花前花后营养器官生产储藏干物质及氮素向籽粒的运输量最高,且与其他水氮组合处理差异显著。各氮素处理下,60~200 cm土层土壤耗水量均为A₃>A₄>A₂>A₁;A₃B₃处理下的水分利用效率和氮素利用效率高于A₃B₄、A₄B₃和A₄B₄。A₃B₃处理显著提高了开花后7~28 d的旗叶净光合速率、气孔导度和蒸腾速率,有利于小麦进行光合作用合成碳水化合物。水氮组合效应显著影响籽粒产量和产量构成,且A₃B₃处理下小麦产量最高,达到9400 kg·hm^-2。综上,450 m³·hm^-2和180 kg·hm^-2的水氮组合处理可以显著提高小麦干物质和氮素积累量,并促进干物质和氮素向籽粒运输,与高水肥处理相比,可以有效提高水分利用效率和氮素利用效率,有利于增强小麦旗叶的光合能力,产生更多的碳水化合物,增加籽粒产量。     

不同播期冬小麦氮素出籽效率与氮素利用及转运的相关性

为探讨不同播期冬小麦氮素出籽效率与氮素利用及转运的关系,在2014—2016年2个生长季,比较了不同播期(S₁:9月24日;S₂:10月1日;S₃:10月8日;S₄:10月15日;S₅:10月22日)冬小麦氮素出籽效率、氮素利用和转运的差异及相互间的关系.结果表明: 籽粒产量和单位面积粒数在不同播期处理间未发生显著差异.推迟播期降低了地上部氮素积累量和穗部氮素积累量,从而降低了氮素吸收效率,但明显提高了氮素利用效率和氮素出籽效率.氮素出籽效率与氮素利用效率呈正相关,而与氮素吸收效率呈负相关,与氮素利用率无显著相关关系.氮素营养指数随播期推迟趋于最佳状态,与氮素出籽效率的改善展现出同步性.推迟播期显著降低了花前营养器官氮素转移量和花后氮素积累量,但明显改善了花前营养器官氮素转运效率.氮素出籽效率与氮素转运效率之间存在正相关关系,说明氮素转运效率的改善一定程度上有利于穗部氮素生产籽粒能力的提升.综合来看,适当推迟播期减少了氮素吸收,但提高了氮素利用效率和氮素出籽效率,改善了氮素供应状态.研究结果为本地区冬小麦生产中氮素减施增效的实施提供了理论依据.     

灌溉和种植方式对冬小麦耗水特性及干物质生产的影响

于2008—2010年通过田间试验,以高产中筋冬小麦品种济麦22为材料,设等行距平作、宽窄行平作、沟播3种种植方式,每种种植方式下设不灌水(W0)、拔节水(W1)、拔节水+开花水(W2)、拔节水+开花水+灌浆水(W3)4种灌溉处理(每次灌水量为60 mm),研究不同灌溉和种植方式对冬小麦耗水特性及干物质积累与分配规律的影响.结果表明:随灌水量的增加,3种植方式下农田总耗水量均增加,灌水量占总耗水量的比例也增加,而土壤贮水消耗量及其占总耗水量的比例显著降低;与W0处理相比,各灌水处理提高了开花后干物质的积累量、小麦籽粒产量,而水分利用效率(WUE)降低.同一灌溉条件下,与其他两种种植方式相比,沟播方式土壤贮水量消耗比例、籽粒产量和WUE均较高.综合考虑小麦的籽粒产量和WUE,沟播结合灌拔节水+开花水是华北平原冬麦区较适宜的节水种植方式.     

灌溉和种植方式对冬小麦耗水特性及干物质生产的影响

于2008-2010年通过田间试验,以高产中筋冬小麦品种济麦22为材料,设等行距平作、宽窄行平作、沟播3种种植方式,每种种植方式下设不灌水(W₀)、拔节水(W₁)、拔节水+开花水(W₂)、拔节水+开花水+灌浆水(W₃)4种灌溉处理(每次灌水量为60 mm),研究不同灌溉和种植方式对冬小麦耗水特性及干物质积累与分配规律的影响.结果表明： 随灌水量的增加,3种植方式下农田总耗水量均增加,灌水量占总耗水量的比例也增加,而土壤贮水消耗量及其占总耗水量的比例显著降低;与W₀处理相比,各灌水处理提高了开花后干物质的积累量、小麦籽粒产量,而水分利用效率(WUE)降低.同一灌溉条件下,与其他两种种植方式相比,沟播方式土壤贮水量消耗比例、籽粒产量和WUE均较高.综合考虑小麦的籽粒产量和WUE,沟播结合灌拔节水+开花水是华北平原冬麦区较适宜的节水种植方式.     

太阳辐射减弱条件下冬小麦光合作用和干物质生产的模拟

为了深入了解太阳辐射减弱对冬小麦光合作用及产量的影响,在大田试验条件下设置了自然太阳总辐射(CK)、60%CK、40%CK、20%CK和15%CK5个太阳辐射处理组,同时测定了太阳辐射变化对不同生育期冬小麦光合作用及干物质生产的影响。在此基础上,对单叶光合速率、生理年龄、温度、CO2和叶面积指数等因子的影响函数进行了修订,建立了反映太阳辐射变化对冬小麦光合作用和干物质生产影响的作物生长模型。结果表明:该模型能较好地反映太阳辐射减弱条件下冬小麦光合速率和干物质生产的变化,其中光合速率和总干物质质量的平均相对误差分别为4.1%和8.3%,在水肥充足条件下,与对照CK相比,60%～15%CK处理的冬小麦光合速率和总干物质质量分别下降了23%～48%和35%～57%。     

不同施氮水平对苦荞不同品种生长发育、干物质转运和产量的影响

该研究以西农9940和黔苦3号为材料,设置(N1) 90、(N2) 180、(N3) 270 kg·hm-2三个氮肥处理水平,分析不同施氮量处理对两个苦荞品种的生长、营养器官干物质积累转运和施氮量对籽粒灌浆特性和产量的影响。结果表明:(1)施氮肥显著促进苦养生长发育。随着施氮量的增加,苦荞株高、叶片SPAD值和干物质积累量呈增长趋势,于N3处理达到最大值,显著高于N1和N2处理。且在同一施氮处理条件下,黔苦3号的株高、SPAD值和干物质积累量均优于西农9940。就转运率而言,苦荞的两个品种表现不一致,施氮显著提高西农9940茎叶干物质转运率,黔苦3号则相反;叶片贡献率随施氮量增加显著增加,茎贡献率则没有显著变化。(2)随着施氮量的增加,苦荞籽粒灌浆持续期增加,最大灌浆速率到达时间延长,平均灌浆速率却降低,百粒重呈下降趋势;在同一施氮处理条件下,西农9940较黔苦3号灌浆速率更快,百粒重更大。(3)随着施氮量的增加,产量及其构成因素呈先增加后减少的趋势。西农9940的产量在N2处理达到最高,为1 650 kg·hm-2,较N1、N3处理增产了45.6%和28.2%;黔苦3号的产量在N1处理达到最高,为616. 7 kg·hm-2,较N2和N3处理增产了12.8%和51.6%。在黄土高原旱作区苦荞种植因品种不同而选择不同的施氮量,建议西农9940最佳施氮量为180～270 kg·hm-2,黔苦3号最佳施氮量为90～180 kg·hm-2。     

Relationships between dynamics of nitrogen uptake and dry matter accumulation in maize crops. Determination of critical N concentration

The concept of critical nitrogen concentration(%N _c) has been proposed as the minimum%N in shoots required to produce the maximum aerial biomassat a given time. Several authors have shown that%N _c declines as a function of aerial biomassaccumulation (W) and the %N _c –W relationship has been proposed as a diagnostic tool of N statusin different crops, excluding maize. From data obtained in five nitrogenfertilisation experiments in irrigated maize crops, 26 critical data-pointswere selected with a precise statistical procedure. An allometric relationwas fitted and a critical %N−W relationshipmodel is proposed in maize as: If W < 1 t ha^-1%N _c = 3.40 If 1 t ha^-1≤ W ≤ 22 t ha^-1%N _c = 3.40(W)^−0.37 The model is applicable to maize crop development between emergenceand silking + 25 days. The model was tested and validated with dataobtained in a network of 17 N fertilisation experiments conducted inFrance under contrasting pedoclimatic conditions. In only nineout of 280 data-points (3.2%), the plant N status was mispredictedwhen ±5% error around %N _c wasallowed. A critical N uptake model (Nu_c, kg Nha^-1) is proposed as Nu_c = 34 (W)^0.63 A comparison between Nu_c and N uptake observedin N treatments giving the maximal grain yields has shown that maizecrops assimilate at least 30 kg N ha^-1 in a storage N poolat the silking stage. The significance of the critical%N−W and Nu−W relationships is discussed in relation to theoretical models proposed inwhole plant ecophysiology. Different relationships calculated betweenleaf area index and aerial biomass accumulation, and between N uptakeand leaf area were consistent with previous results for other crops.This strengthens the interest of the critical%N−W relationship for use as diagnostictool of nitrogen status in maize crops. This revised version was published online in June 2006 with corrections to the Cover Date.     

Warming impacts on the dry matter accumulation,and translocation and nitrogen uptake and utilization of winter wheat on the Qinghai-Xizang Plateau

Aims Global warming is expected to be the strongest in high altitude mountainous areas, which are more ecologically fragile and economically marginalized. The Qinghai-Xizang Plateau is among such areas most vulnerable to global warming, and more than 80% of its population depends on subsistence agriculture. The aim of this study is to understand the impacts of warming on indigenous crop production, which can help to devise better strategies for crop adaptation and food security in this area.Methods A field warming experiment using a facility of free air temperature increase was conducted to simulate the predicted warming level in Caigongtang town, Lhasa City, China. The experiment consisting of two treatments (warmed and non-warmed) was performed using a completely random design with three replicates. An infrared heater (180 cm in length and 20 cm in width) of 1 500 W was suspended 1.5 m above the ground in each warmed plot. In each non-warmed plot, a ‘dummy’ heater of same dimensions was also suspended to mimic the shading effects. The warming treatment was performed from the sown date to the harvest date. We measured dry matter and nitrogen accumulation, partition and translocation of winter wheat (Triticum aestivum) using ‘Shandong 6’ under warming and control treatments.Important findings Results showed that, with 1.1 °C increase in daily mean air temperature during winter wheat growing season, the dry matter accumulation rate at population level from sowing to anthesis stage, grain dry matter partition ratio and contribution of dry matter translocation amount to grain after anthesis were 27.5%, 5.6% and 68.6% higher, respectively, in the warmed plots than those in the non-warmed plots. Meanwhile, warming increased nitrogen accumulation rate at population level of winter wheat. Nitrogen distribution proportions in grain and nitrogen translocation efficiency from vegetative organs to grain after anthesis in the warmed treatment were 6.0% and 5.5% higher than those in the non-warmed treatment, respectively. Compared with non-warmed treatment, warming decreased harvest index by 3.1%, though the difference was not statistically significant. Grain yield, nitrogen uptake efficiency, nitrogen partial factor productivity and nitrogen harvest index were 8.1%, 20.8%, 8.1% and 6.0% higher, respectively, in the warmed plots than those in the non-warmed plots. In conclusion, an increase in daily mean air temperature of about 1.1 °C can enhance plant growth during the pre-anthesis phase by mitigating the low temperature limitation, and accelerate dry matter and nitrogen partition and translocation to the grain after anthesis in winter wheat. These results suggest that warming may benefit winter wheat production through increasing nitrogen use efficiency in high altitude areas.     

Plant development,and N and P use of winter barley

Winter barley (Hordeum vulgare L. cv. Kamiak) was grown at three landscape positions of a representative toposequence in the Palouse region of eastern Washington. This region is typified by rolling topography marked by severe erosion of steep slope positions that has altered soil productivity in the landscape. The objectives of this research were to identify soil factors which limit plant development and nutrient use efficiency in the eroded slope positions, and to suggest potential management practices for overcoming these limitations. Direct drilling into cereal stubble resulted in retardation of early plant development of winter barley. Lower N and P accumulation by early tillering under no-till conditions were related these effects on dry matter. These reductions were generally overcome by anthesis. Comparison of tillage systems demonstrated that direct drilling into crop residues increased yields by 16% over conventional tillage at an eroded ridgetop position of one of the two toposequences examined. Benefits derived in the no-till system under the high N rates occurred during grainfilling, as indicated by greater numbers of heads and higher kernel weights at final harvest. Tillage system had no effect on grain production at other landscape positions that featured higher overall yields under either tillage system. Short-term benefits of no-till systems may be most evident at slope positions where water use is most limited.     

灌溉对干旱区冬小麦干物质积累、分配和产量的影响

为探明灌溉对干旱区冬小麦(Triticum aestivum)产量、水分利用效率(WUE)、干物质积累及分配等的影响, 以甘肃河西走廊冬小麦适宜种植品种‘临抗2号’为材料进行了研究。在冬季灌水180 mm的条件下, 生育期以灌水量和灌水次数等共设置5个处理, 分别为: 拔节期灌水量165 mm (W1)、拔节期灌水量120 mm +抽穗期灌水量105 mm (W2)、拔节期灌水量105 mm +抽穗期灌水量105 mm +灌浆期灌水量105 mm (W3)、拔节期灌水量75 mm +抽穗期灌水量75 mm +灌浆期灌水量75 mm (W4)、拔节期灌水量105 mm +抽穗期灌水量75 mm +灌浆期灌水量45 mm (W5)。结果表明: 随着生育期的推进, 土壤有效含水量(AWC)受灌水次数及灌水量影响更加明显; W3、W4处理的土壤各层AWC在灌浆期均较高; 叶面积指数(LAI)下降慢, 延缓了生育后期的衰老; 生育后期干物质积累增加, 提高了穗粒数、千粒重和籽粒产量。籽粒产量以W3处理最高, 但W4具有最高的WUE, 且籽粒产量与W3无显著差异, 但W4较灌溉总量相同的W2和W5以及灌水量最少的W1具有明显的指标优势。W1、W2、W5处理灌浆期各层土壤AWC均较低, 花后LAI下降快, 干物质积累减少, 灌浆持续期缩短, 穗粒数和千粒重减少, 最终表现为籽粒产量和WUE下降。灌浆期水分胁迫可促进花前储存碳库向籽粒的再转运, 并随着干旱胁迫的加重而提高, 对籽粒产量起补偿作用; 水分胁迫提高了灌浆速率, 但缩短了灌浆持续期。相关性分析表明, 灌浆持续期、有效灌浆持续期、有效灌浆期粒重增加值和最大籽粒灌浆速率出现时间与千粒重和籽粒产量均呈正相关。综合考虑, 拔节、抽穗及灌浆期各灌溉75 mm是高产高WUE的最佳灌水方案。     

Growth and NPK uptake of high-yielding cotton grown at different nitrogen levels in a permanent-plot experiment

Growth and N, P, K uptake of Acala SJ-2 cotton (Gossypium hirsutum) were investigated in an irrigated permanent-plot field (Typic chromoxerert) at Bet Dagan, Israel, under semi-arid conditions using different nitrogen levels: 0, 60, 120, 180 and 240 kg N ha⁻¹. The total dry matter accumulation at these levels was 9.0, 10.7, 15.1, 17.1 and 15.6 ton ha⁻¹, respectively. The uptake of N, P and K was 110, 144, 267, 322 and 301 kg N ha⁻¹∶31, 34, 46, 44 and 38 kg P ha⁻¹; and 120, 151, 208, 251 and 230 kg K ha⁻¹, respectively. Dry matter production, as well as N, P, K uptake by the cotton plants were greatly increased by raising the N application levels to 120 or 180 kg N ha⁻¹, but the pattern of accumulation and relative distribution of dry matter and NPK among plant organs were not considerably affected. Joint contribution from the Dept. of Soil Chemistry and Plant Nutrition, ARO, the Volcani Center, Bet Dagan, Israel (No. 1413-E, 1985 series)     

贵州黄壤区辣椒干物质、氮素积累与分配及氮素利用对新型肥料的响应

为探索贵州黄壤区施用新型肥料对辣椒种植的增产效应,通过盆栽试验研究了保水型(BSX)、稳定性(WDX)、包膜型(BMX)缓释肥和长效氮肥(CXDF)4种新型肥料对‘博辣5号’辣椒的干物质、氮素积累与分配,以及氮素利用效率的影响.结果表明: 施用新型肥料可以明显影响辣椒干物质和氮素的积累与分配,辣椒氮素积累快速增长开始时间和结束时间较干物质分别提前17~26 d和28~45 d,且氮素积累快速增长持续期也较干物质缩短7~23 d,表明氮素积累的发生时间要先于干物质积累;与普通复合肥(FHF)处理相比,新型肥料处理的干物质和氮素积累均出现明显滞后,以BMX处理的滞后时间最长,但是WDX处理的快速增长持续期较短且最大积累速率最高,说明稳定性缓释肥可实现养分短时间内的高效利用;BSX和BMX处理的花后干物质和氮素积累量占总干物质和总氮的比例分别为62.9%和20.1%、73.3%和20.5%,而WDX处理则分别为59.3%和11.6%,说明保水型和包膜型缓释肥相对有利于辣椒花后干物质积累和氮素同化,而稳定性缓释肥则更有利于花前干物质和养分积累;与FHF处理相比,施用新型肥料(保水型、稳定性和包膜型缓释肥)可显著提高辣椒的氮素利用效率,以稳定性缓释肥的氮肥偏生产力、氮肥农学效率和氮肥表观利用率最高,分别为66.74 kg·kg^-1、44.28 kg·kg^-1和54.6%.新型肥料适用于贵州辣椒种植栽培,以稳定性缓释肥的施用效果最佳.     

5-氨基乙酰丙酸(ALA)对冬小麦花后干物质生产和旗叶衰老的影响

以百农矮抗58小麦为材料,采用大田试验的方法,研究了始穗期喷施不同浓度(0,10、30、50 mg·L-1)的5-氨基乙酰丙酸(ALA)对冬小麦花后干物质生产和旗叶衰老的影响.结果表明:10～50 mg·L-1 ALA处理有利于植株对干物质的积累,至成熟期其干物质总量明显高于对照(0 mg·L-1);10～50 mg·L-1 ALA处理各器官干物质的分配率与对照没有显著性差异,但其花后生产的干物质对产量的贡献率显著高于对照;在开花期,10～50 mg·L-1ALA处理的叶面积指数与对照没有显著性差异,但在乳熟期和腊熟期,叶面积指数显著高于对照.从开花期至蜡熟期,10～50 mg·L-1 ALA处理的旗叶SPAD值和净光合速率均高于对照;在灌浆后期,ALA处理降低了旗叶丙二醛(MDA)含量和相对电导率.与对照相比,10～50mg·L-1 ALA处理冬小麦的穗粒数、千粒重和产量显著增加,其中以30 mg·L-1 ALA处理增产效果最大.     

基于源库生长单位的温室番茄干物质生产-分配模拟

为了量化研究温室番茄果穗间干物质的分配,提高温室番茄栽培的效益,采用源库生长单位的测定方法,将经典的单叶同化物生产模型与GreenLab模型相结合,构建了干物质向源库生长单位内茎节、叶片、果实分配的动态模型,利用越冬茬、早春茬和春夏茬温室番茄各器官的干物质测定数据对模型进行了验证.结果表明:所构建的模型模拟结果与实测结果吻合性较好,不同茬口同化物生产模拟值与实测值的回归方程斜率为0.93,R~2为0.92;源库生长单位内茎节、叶片、果实以及根系的模拟值与实测值间回归方程斜率在0.85～0.89之间,其相对误差(R_e)均值分别为5.3%、5.6%、8.1%和3.6%,说明模型的模拟准确度较高,可为不同茬口温室番茄栽培管理提供理论依据和决策支持.     

交替根区滴灌下不同施氮量对葡萄干物质积累、分配和产量的影响

本试验采用盆栽的方法,在避雨栽培条件下,研究不同的灌溉方式和供氮水平对葡萄干物质积累与分配、产量和水氮生产效率的影响,以探讨北方鲜食葡萄生产最佳的水氮耦合管理模式.灌溉方式包括常规灌溉100％灌溉量(CDI)、单侧固定根区灌溉50％灌溉量(FDI)和双侧根区交替灌溉50％灌溉量(ADI);土壤施氮浓度设置0.4(N1)...