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1.
为探讨大兴安岭林区蒙古栎地上生物量分配模式,并构建可加性生物量模型,采用破坏性取样法共采集了78株蒙古栎的干材、树皮、树枝和树叶的生物量,其中31株通过全挖法收集根系生物量,计算地上各组分生物量占地上生物量的比例,分析其随胸径的变化趋势。以胸径、树高、冠幅为自变量,探讨各组分的最优生物模型;采用似乎不相关模型构建地上各组分生物量的可加性模型,采用留一交叉法对模型进行验证。结果表明,干材占地上生物量的51%;随胸径的增加,干材生物量占比较为稳定,树枝生物量占比呈上升趋势,树皮和树叶则相反,根茎比表现为先急、后缓的下降趋势,均值为0. 36;所有生物量模型均表现出良好的拟合效果(调整决定系数R2Adj为0. 907~0. 984),采用胸径为自变量的根系生物量模型拟合效果最佳,基于胸径和树高组合变量的干材和树皮生物量模型可取得较好结果,而以胸径和冠幅为自变量的树枝和树叶生物量模型效果最佳。本研究得出的生物量模型对大兴安岭蒙古栎生物量的核算具有参考价值。 相似文献
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针对雾培马铃薯幼苗根系器官常受气温影响而导致植株生育不良的生产实际,试验探讨了增施钙素对低温环境下雾培马铃薯幼苗抗冷性的调节作用,以期为低温生产季节增施钙素来增强马铃薯幼苗抗冷性提供依据。试验结果表明,增施钙素可以降低马铃薯幼苗叶片的离子渗透率和膜脂过氧化产物丙二醛(MDA)的积累量,同时还能有效提高叶片中抗氧化保护酶(POD、CAT和SOD)活性和渗透调节物质(可溶性蛋白质和可溶性糖)的含量以及抑制幼苗根系活力的下降,但增施钙素未能显著提高幼苗叶片中脯氨酸的含量。以上结果说明,钙素在雾培马铃薯幼苗抵御冷害的生理调节过程中发挥了重要作用,通过增施适宜浓度的钙素在一定程度上可以改善雾培马铃薯幼苗的抗冷性。 相似文献
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以棉花(Gossypium hirsutum L.)为试验材料,采用防雨棚下桶栽土培方法,进行调亏灌溉(Regulated deficit irrigation,RDI)对棉花根、冠生长的影响研究。试验采用二因素随机区组设计,设置4个水分调亏阶段:苗期(I)、蕾期(II)、花铃期(III)和吐絮期(IV);每个调亏阶段设置3个水分调亏度:轻度调亏(L)、中度调亏(M)和重度调亏(S),土壤相对含水率(占田间持水率的百分数)控制上、下限分别为60%~65%FC(Field capacity)、50%~55%FC和40%~45%FC;另设全生育期保持适宜土壤水分处理作为对照(CK),土壤相对含水率控制下限分别为60%FC(苗期)、60%FC(蕾期)、70%FC(花铃期)和60%FC(吐絮期)。分别在水分调亏期间和复水后测定各处理根系参数和地上干物质质量。试验结果表明,RDI对植株根、冠生长发育的影响因不同水分调亏阶段和不同水分调亏度而异。水分调亏不改变棉花根系生长的原有总体趋势,但对根系生长速率具有促进作用。棉花各生育阶段的中度水分调亏(50%~60%FC)在调亏期间对根系生长有明显促进效应或维持较高的根质量,复水后有不同程度的根系补偿生长效应或延缓根系衰亡作用,后期仍保持较高的根冠比(R/S),因而是协调棉花根/冠关系的适宜水分调亏处理。RDI可以有效调控棉花根/冠生长关系。 相似文献
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中瑞保水剂 ( PAMN-LC)对无离子水的吸水能力为 67.5ml/g,且随着产品配方和生产工艺的改进 ,其吸水性能有着不断提高的趋势。试验结果表明 ,中瑞保水剂 ( PAMN-LC)吸水总量的 78.4 2 %为有效水 ,无效水所占比例只有 2 1 .58% ;随着保水剂施用量的增加 ,土壤的持水能力也明显增加 ;施用中瑞保水剂PAMN-JCN对提高冬小麦出苗率有明显的效果 ,当土壤含水率介于 1 2 .1 %~ 1 6.8%之间时 ,用保水剂拌种可使冬小麦提早 1~ 3d出苗 ,出苗增加 2 5%~ 31 .7% ;沟施保水剂可使出苗率增加 3.3%~ 8.3% ;施用中瑞保水剂 PAMN-LC,其在苗期的主要作用是促进根系发育、增大根冠比 ,拔节以后则转为促进地上部发育。另外 ,施用中瑞保水剂有利于保持冬小麦叶片较长时间地处于展开状态 ,根系的颜色也比较深 ,多呈浅褐色。 相似文献
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调亏灌溉对冬小麦根冠生长影响的试验研究 总被引:2,自引:1,他引:2
以冬小麦为试验材料,采用防雨棚下桶栽土培方法,就调亏灌溉(RDI)对作物根、冠生长的影响进行了试验研究。试验采用二因素随机区组设计,冬小麦设置5个水分调亏阶段,每个调亏阶段设置3个水分调亏程度,另设全生育期充分供水处理为对照(CK)。分别在水分调亏期间和复水后测定各处理根系参数和地上干物质质量。结果表明,RDI对植株根冠生长发育的影响因不同水分调亏阶段和不同水分调亏度而有所不同。在水分调亏期间冬小麦根系生长受到强烈抑制,但复水后根系具有"补偿生长效应"或"超补偿生长效应"。冬前适度水分调亏(调亏度55%FC~65%FC)对根系生长具有正效应;返青—拔节阶段不同程度水分调亏复水后均有"补偿生长效应"或"超补偿生长效应",而且这种"补偿生长效应"随水分调亏度加重呈增强趋势。冬小麦水分调亏均增大根冠比(R/S),且随水分调亏度加重,R/S明显增大。因此,RDI可以作为冬小麦根冠生长调控的有效方法。 相似文献
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Distribution of roots and root length density in a maize/soybean strip intercropping system 总被引:1,自引:0,他引:1
Yang Gao Aiwang Duan Xinqiang Qiu Jingsheng Sun Junpeng Zhang 《Agricultural Water Management》2010,98(1):199-212
In a field experiment in the Yellow River Basin conducted in 2007 and 2008, it was found that, under full irrigation, the roots of maize not only penetrated deeper than those of soybean but also extended into soybean stands underneath the space between inner rows of soybean. The roots of soybean, however, were confined mainly to the zone near the plants. Horizontal growth of the roots of both the crops was confined mainly to the soil layer 16-22 cm below the surface, a layer that lay above an existing plough pan. Root length density (RLD) was much higher in the top layer (0-30 cm deep) and in the zone closer to the plants. The exponential model proved suitable to describe the RLD vertically and horizontally in both sole cropping and in intercropping. 相似文献
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Experimental results obtained from a greenhouse trial with common bean (Phaseolus vulgaris L.) plants performed to test model hypotheses regarding the onset of limiting hydraulic conditions and the shape of the transpiration reduction curve in the falling rate phase are presented. According to these hypotheses based on simulations with an upscaled single-root model, the matric flux potential at the onset of limiting hydraulic conditions is as a function of root length density and potential transpiration rate, while the relative transpiration in the falling rate phase equals the relative matric flux potential. Transpiration of bean plants in water stressed pots with four different soils was determined daily by weighing and compared to values obtained from non-stressed pots. This procedure allowed determining the onset of the falling rate phase and corresponding soil hydraulic conditions. At the onset of the falling rate phase, the value of matric flux potential Ml showed to differ in order of magnitude from the model predicted value for three out of four soils. This difference between model and experiment can be explained by the heterogeneity of the root distribution which is not considered by the model. An empirical factor to deal with this heterogeneity should be included in the model to improve predictions. Comparing the predictions of relative transpiration in the falling rate phase using a linear shape with water content, pressure head or matric flux potential, the matric flux potential based reduction function, in agreement with the hypothesis, showed the best performance, while the pressure head based equation resulted in the highest deviations between observed and predicted values of relative transpiration rates. 相似文献
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针对龟石灌区农业用水效率低下、浪费严重等问题,提出了节水措施,分析了节水改造的潜力与效益。灌区水资源优化配置与合理利用,提高灌溉水利用率和水分生产率,富余水量用于城市供水及发电,提高单位水量的价值不仅是必要的,而且是灌区发展的必由之路。 相似文献
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基于蒸散发调控及排水重复利用的灌区节水潜力 总被引:2,自引:0,他引:2
基于改进SWAT模型,以漳河灌区为背景,模拟分析了不同情景下蒸散发及排水比的变化,并进一步分析灌区节水潜力.结果表明,水田蒸散发由大到小为淹灌、间歇灌溉和薄浅湿晒.基于蒸散发消耗调控,研究区现状条件下理论节水率为14.5%,远大于实际节水潜力;与淹灌相比,间歇灌溉和薄浅湿晒节水率分别为1.6%和2.4%.基于排水重复利用,研究区现状条件下理论节水率为16%;塘堰汇流面积比例从现状的30%提高到50%,排水管理节水率及实际灌溉节水率分别为3.8%和1%,而传统的灌溉取水节水率为19.9%;可见,不同计算方法得到的节水潜力存在很大差异. 相似文献
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以我国北方普遍种植的经济作物线辣椒为研究对象,根据线辣椒的生理生长特点,通过盆栽试验,研究了苗期不同土壤水分下限对线辣椒长势、产量和WUE的影响。结果表明,在试验条件下,土壤水分下限控制在田间持水率(θF)的45%~60%时,线辣椒生长状况良好,50%θF时线辣椒的生物量、根冠比最大;各处理按线辣椒单株产量大小排序为:处理4〉处理3〉处理2〉处理1〉处理5〉处理6;各处理按线辣椒全生育期WUE大小排序为:处理3〉处理4〉处理2〉处理1〉处理5〉处理6。产量最高时的苗期土壤含水率为50%θF,WUE最高的苗期土壤含水率为55%θF,从而得出线辣椒获得较高产量所对应的苗期土壤水分下限为(50%~55%)θF。 相似文献
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以2012—2013年田间对比试验为基础,深入探讨了不同覆盖耕作模式对春玉米根冠比、根系时空分布、地上生物量、产量及水分利用效率的调控效应。试验设置4个覆盖处理(浅松覆盖、条带覆盖、残茬覆盖、免耕全覆盖)及对照传统耕作处理,分别在拔节期和收获期取样观测,并采用SPSS统计软件对数据进行显著性分析。结果表明:各覆盖耕作模式对根系、地上生物量及根冠比具有前控后助效应,且拔节前期影响显著。此外拔节前期免耕全覆盖长势不如对照,但拔节后期4种覆盖模式地上生物量平均高于对照1.56%~5.48%;根质量密度平均高于对照15.10%~32.36%,根冠比平均高于对照10.38%~32.74%。产量与水分利用效率分别平均高于对照3.79%~12.40%和4.22%~12.31%。其中浅松覆盖处理在玉米根系形成、增产及水分利用效率等方面效果最佳,适宜北方寒旱地区推广。 相似文献
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采用浸渍法制备了Fe-Ce/白云石催化剂,运用SEM和XRD检测对催化剂进行了表征,在自行搭建的固定床气化炉试验台上进行高温水蒸气催化气化试验,研究了助剂含量、气化温度等因素对松木棒水蒸气气化特性的影响,以及催化剂使用次数对气体组分和催化剂积碳沉积的影响。试验结果表明,助剂Fe和Ce能够很好地负载于白云石上,助剂负载量为8%Fe-2%Ce的催化剂气化效果较好。用该催化剂进行不同温度的松木棒水蒸气气化试验,温度从750℃升高至950℃,产气率、产氢率分别由750℃的1. 05 m3/kg和31. 67 g/kg提高到900℃的1. 56 m3/kg和65. 39 g/kg,与无催化剂的气化试验相比,900℃的产气率、产氢率分别增加了0. 15 m3/kg和16. 27 g/kg,氢气体积分数由39. 02%升高至46. 95%。在800℃时对催化剂进行重复利用3次气化试验,氢气体积分数由第1次的40. 34%降低至第2次的38. 97%和第3次的34. 95%,积碳量由第1次的21. 55 mg/g升至第3次的31. 61 mg/g,催化活性降低。 相似文献
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Regulated Deficit Irrigation (RDI) is an irrigation scheduling technique, originally developed for fruit orchards, that has been successfully adapted for winegrape production. The aim of this work is to evaluate the effect of RDI in vegetative growth, yield and harvest quality in ‘Tempranillo’ vineyards grown under semiarid conditions typical in Mediterranean areas. Two RDI strategies were compared with conventional irrigation practices (CI). CI that consisted in a progressive increase in water deficit as summer progressed, whereas RDI strategies (RDI1 and RDI2) had in common a deficit period just after fruit set and, in RDI2, vines were subjected to an additional stress period shortly after veraison. The experiment was carried out in four consecutive seasons in a commercial vineyard.Water stress at the beginning of berry development resulted in an important reduction of both vegetative growth and berry weight in RDI strategies. No differences in sugar concentration were found between treatments, and RDI berries tended to have lower acidity. The most relevant effect of RDI strategies on grape quality was an increase in anthocyanin and phenolics concentration. In RDI1 berries, this increase was mainly an indirect consequence of smaller berry size. However, in the RDI2 treatment the higher berry anthocyanin concentration reported was not exclusively due to a reduction in berry size. Since harvest quality has been clearly improved by any of the RDI strategies in both years, it can be concluded that RDI constitutes an interesting technique to be applied in ‘Tempranillo’ vineyards grown in semiarid areas aiming to obtain high quality grape. 相似文献
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采用一步水热法原位合成工艺制备了Ni-Zn/玄武岩复合催化剂,对催化剂微观形貌和表面元素分布进行了表征。以松木颗粒为原料、水蒸气为气化剂,采用下吸式管式气化炉实验平台,研究了Ni-Zn/玄武岩复合材料在不同温度下高温蒸汽的催化气化效果,通过考察气体组分变化,探讨Ni-Zn/玄武岩复合催化剂催化性能随温度变化的规律,并与无催化剂和以白云石为催化剂的催化性能进行实验对比。实验结果表明:水热反应温度为130℃,反应时间为12 h时,Ni、Zn能很好地负载在玄武岩纤维表面;与不加催化剂和加入白云石催化剂相比,Ni-Zn/玄武岩复合催化剂气化温度在950℃时催化效率明显提升,氢气体积分数增加明显,分别由无催化剂时的58. 6%、加入白云石催化剂时的50. 02%升高至63. 28%。 相似文献
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针对温室作物秋冬季节CO2气肥严重不足的问题,设计了适用于普通温室大棚的基于生物质原料发酵的二氧化碳施肥器。采用作物秸秆在好氧发酵作用下进行发酵,制取二氧化碳。同时,采用合理的自动控制策略,获取生物质发酵过程中适宜的温度及水分等条件,并试验研究了生物质发酵制取CO2的最佳条件,验证了该施肥器用于温室补施二氧化碳的可行性。试验结果表明:利用秸秆等农作物废弃物(秸秆+好氧发酵菌)生物发酵产生CO2的最佳条件为:温度45℃、含水量为70%、初始碳氮比为40:1,产气速率最快;碳氮比对CO2的释放影响最大,温度影响次之,含水量影响最小;在此条件下一次上料可以连续12天让面积120m2的温室CO2浓度保持在1 200×10-6以上,满足温室使用需求。 相似文献
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不同灌水量对盆栽棉花干物质积累和分配的影响 总被引:1,自引:0,他引:1
为研究不同灌水量对转基因抗虫棉生物量的影响,在盆栽条件下,以华杂棉H318为试验材料,参照自然蒸发量,设置5个灌溉处理(T1、T2、T3、T4、T5),研究不同灌水量对棉花干物质积累和分配的影响。结果表明,随灌水量增加,生殖器官干质量和铃数呈上升趋势,根系和地上部分生物量增加。"果节/叶面积"以T5最大,"铃数/叶面积"T1最高,"生殖器官干质量/叶面积"随灌水量减少而降低。T3处理根冠比和生殖器官干物质分配率较高,生物量灌溉水利用效率最大。在提高水分利用效率的前提下,T3为最佳的灌水比例。 相似文献
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为了探明肥液质量浓度和生物质掺混质量比对微润灌溉土壤水分入渗特性的影响,采用室内土箱模拟试验的方法,设置3个肥液质量浓度水平(清水F0:0 mg/L,低浓度FL:200 mg/L,高浓度FH:400 mg/L)和4个生物质掺混质量比水平(自然风干土B0:0 g/kg,低掺混量BL:15 g/kg,中掺混量BM:30 g/kg,高掺混量BH:45 g/kg),以发酵腐熟花生壳粉末为掺混生物质,研究微润灌溉的水分入渗速率、累积入渗量、湿润体体积以及湿润体质量含水率的分布特征.试验结果表明:肥液质量浓度和生物质掺混质量比对微润灌溉的初始入渗速率、稳定入渗速率、累积入渗量和湿润体质量含水率均值影响均具有统计学意义.与水平F0B0相比,增加肥液质量浓度和生物质掺混质量比可提高初始入渗速率13.02%~44.85%、稳定入渗速率13.50%~48.78%、累积入渗量5.65%~56.62%和湿润体质量含水率均值6.62%~30.09%;不同入渗时间内的累积入渗量符合Kostiakov模型;湿润体体积随肥液质量浓度和生物质掺混质量比增大而增大,且湿润体体积与入渗时间呈二次多项式关系;湿润体剖面面积和灌水均匀系数随肥液质量浓度和生物质掺混质量比增大而增大. 相似文献
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Could trunk diameter sensors be used in woody crops for irrigation scheduling? A review of current knowledge and future perspectives 总被引:3,自引:0,他引:3
M.F. Ortuño F. Moreno D.S. Intrigliolo C.D. Mellisho R. Domingo M.C. Ruiz-Sánchez J. Casadesus A. Torrecillas 《Agricultural Water Management》2010,97(1):1-35
The use of trunk diameter fluctuations and their derived parameters for irrigation scheduling in woody crops is reviewed. The strengths and weaknesses of these continuously measured plant-based water stress indicators compared with other discretely measured indicators for diagnosing plant water status in young and mature trees are discussed. Aspects such as sensor reading variability, signal intensity and the relationship between trunk diameter fluctuations and plant water status are analyzed in order to assess their usefulness as water stress indicators. The physiological significance of maximum and minimum daily trunk diameter and maximum daily trunk shrinkage (MDS) are also considered. Current knowledge of irrigation protocols and baselines for obtaining maximum daily trunk shrinkage reference values is discussed and new research objectives are proposed. We analyze the response of woody crops to continuous deficit irrigation scheduled by maintaining MDS signal intensity at threshold values to generate mild, moderate and severe water stress and assess the possibility of using linear variable displacement transducer (LVDT) sensors in trunk as a precision tool for regulated deficit irrigation scheduling. Finally, the possibility of using MDS signal intensity as a tool to match the irrigation regime to tree water requirements is also reviewed. 相似文献