负水头供不同营养液对温室樱桃番茄生长和产量的影响

采用负水头灌溉装置,通过调节装置的供水吸力值来持续稳定地控制栽培基质的湿度,供给不同浓度磷酸二氢钾（KH₂PO₄）营养液配方进行樱桃番茄基质栽培试验,研究营养液中不同磷酸二氢钾浓度对樱桃番茄株高、茎粗、产量、水肥利用效率和根系活力的影响。结果表明：在负水头供水控水技术条件下,适当提高营养液中磷酸二氢钾浓度,有利于增加樱桃番茄株高、茎粗,效果显著;同时可以提高果实产量、水分利用效率和N、K利用效率以及根系活力。负水头供给营养液樱桃番茄栽培生产中,2.5 S处理即340 mg•L^-1的KH₂PO₄浓度可作为推荐用量。     

A ground-based comparison of nutrient delivery technologies originally developed for growing plants in the spaceflight environment

A ground-based comparison of plant nutrient delivery systems that have been developed for microgravity application was conducted for dwarf wheat (Triticum aestivum L. 'Yecora Rojo') and rapid-cycling brassica (Brassica rapa L. CrGC#1-33) plants. These experiments offer insight into nutrient and oxygen delivery concerns for greenhouse crop production systems. The experiments were completed over a 12-day period to simulate a typical space shuttle-based spaceflight experiment. The plant materials, grown either using the porous-tube nutrient delivery system, the phenolic foam support system, or a solidified agar nutrient medium, were compared by plant-growth analysis, root zone morphological measurements, elemental composition analysis, and alcohol dehydrogenase enzyme activity assay. The results of these analyses indicate that the porous tube plant nutrient delivery and the phenolic foam systems maintain plant growth at a higher level than the solidified agar gel medium system. Root zone oxygenation problems associated with the agar system were manifested through biochemical and morphological responses. The porous tube nutrient delivery system outperformed the other two systems on the basis of plant growth analysis parameters and physiological indicators of root zone aeration. This information is applicable to the current crop production techniques used in greenhouse-controlled environments.     

Ethylene production as an indicator of stress conditions in hydroponically-grown strawberries

As a soilless system, hydroponics eliminates competing weeds and soil-born pests while conserving water and providing conditions that can be quickly altered to suit specific crops. However, stress-induced physiological conditions may arise within the system from factors such as mechanical injury, pests, or inconsistent nutrient flow rates that result in some plants receiving too much or too little water. Most abiotic stress conditions result in increased production of the plant hormone ethylene. High levels of ethylene inhibit growth, cause premature ripening, and induce the onset of senescence, potentially reducing the productivity of hydroponically-grown crops. In this study, we demonstrate that assessing ethylene levels from leaves of hydroponically-grown strawberry plants can be used as an early indicator of stress conditions. Our results demonstrate that there is no significant correlation between ethylene production and temperatures ranging from 15 to 37 °C or with light intensities ranging from 63 to 1500 μmol m⁻² s⁻¹. However, an increase in ethylene production tended to be positively correlated with sampling time; levels were higher during midday compared to early morning or later afternoon. The daily ethylene fluctuations under greenhouse conditions due to sampling time, light intensity, or temperature changes were not significantly high enough to indicate stress conditions. Overall, three system analyses showed altered ethylene production in plants farthest from the pump supplying the nutrient solution. This effect was interpreted to be caused by excess accumulation of nutrient solution around the plant roots, causing increased ethylene production in the leaves. Our results indicate that different watering patterns, manifested as pump pressure or drainage control, was the more difficult component to control in the design of these hydroponic systems. For example, in one system, an increase in ethylene production was measured for the position farthest from the pump, and resulted in those plants having a lower number of flowers and significantly reduced overall plant radii relative to the system average. In a separate experiment, plants from trays that had been flooded for 24 h showed a significant decrease in the plant radii and number of leaves and flowers 1 month after the flooding treatment. We conclude that system-wide ethylene measurements can be used to identify stressed plants within hydroponic systems. This type of analysis would be especially useful as an indicator of general stress conditions no matter the cause, identifying locations that may result in lower plant productivity.     

Nutrient-flow wick culture system for potted plant production: System characteristics and plant growth

To compliment the current subirrigation systems used for production of potted plants, a nutrient-flow wick culture (NFW) system was developed and compared with other subirrigation systems, such as an ebb and flow culture (EBB) system and a nutrient-stagnant wick culture (NSW) system in relation to their system characteristics and plant growth. Kalanchoe (Kalanchoe blossfeldiana cv. New Alter) was cultivated in a 6 cm pot for 10 weeks in each subirrigation system. The water-absorption pattern of the medium, water content of the medium, water loss, algal growth, salt-buildup and plant growth under various culture systems were observed. The water contents of medium under the NFW and EBB systems showed fluctuations from 30 to 40% and from 50 to 60% (by volume), respectively, whereas the water content under the NSW system gradually increased to over 40% without fluctuation. Relative to other systems, the water loss in the NFW system was 50–70% due to the reduction in the evaporation from the surfaces of the trough and medium. Algae appeared in the NSW system because the nutrient solution was always stagnant in the trough, while it was not observed under the NFW system. The dissolved oxygen in the nutrient solution was the highest during the irrigation period and the salinity in the medium was the lowest in the NFW system. With regard to system characteristics, the NFW system was simple, water-saving and efficient. In addition, the growth of kalanchoes in the NFW system was similar to those in the NSW and EBB systems at an irrigation frequency of five times a day.     

椰糠复合基质槽培番茄营养液浓度的研究

以无限生长型番茄‘丰收’为试材,以椰糠∶珍珠岩=3∶1为基质,设置EC值为1.5、2.0、2.5、3.0、3.5、4.0 mS·cm^-1的6种营养液浓度,研究了在不同EC值营养液处理下植株的株高、茎粗、叶片数的生长变化,根系活力、可溶性糖、有机酸、可溶性蛋白质、维生素C含量、产量、干鲜质量、水分利用效率和根区液养分离子浓度等的变化。结果表明:适当提高营养液浓度可以改善番茄品质,但营养液浓度过高盐分累积严重时会导致产量和品质下降。EC值为2.5、3.0、3.5 mS·cm^-1的营养液较适合椰糠复合基质栽培,其中EC值为4.0 mS·cm^-1可作为短期内高品质栽培使用,番茄长季节高产栽培则可以选择EC值为2.0 mS·cm^-1的营养液。     

植物工厂中不同供液方式对辣椒育苗的影响

以植物工厂辣椒育苗为对象,研究漂浮式与潮汐式供液方式对育苗的影响。试验结果表明,漂浮式处理营养液和基质pH值显著高于潮汐式处理,EC值显著低于潮汐式处理;与潮汐式处理相比,漂浮式处理中幼苗株高、茎粗分别增加18.4%,23.6%;漂浮式处理幼苗根尖数、总根长、直径在0~0.5 mm的根长分别增加了37.0%,45.5%,50.1%;幼苗地上部鲜质量、全株鲜质量、地上部含水量、植株含水量分别增加45.6%,32.1%,2.5%,1.8%。漂浮式育苗显著促进辣椒幼苗侧根生长,形成良好的根系系统,促进根系对水分和可溶性盐类的吸收,加快地上部形态建成,提升种苗整体质量。     

不同浓度营养液对油麦菜生长的影响

以油麦菜为试验材料,设计3种日本园试营养液配方浓度,研究其对油麦菜无土栽培生长及产量的影响.研究结果表明,在园试标准营养液配方1/8～1,2浓度范围内,随着营养液浓度的提高,油麦菜各植株鲜质量、小区产量及植株的叶长、株高、叶数、株干质量、根干质量均有不同程度的增加,其中园试标准营养液配方1,2浓度处理最高.     

立管悬钵静止水培缓冲能力研究

研究了立管悬钵静止水培在各种营养逆境下的缓冲能力.结果表明:立管悬钵静止水培在营养液低氧、不良水质、营养液浓度异常等逆境条件下具有一定的缓冲能力.在营养液低氧条件下,立管悬钵静止水培生菜的根长、开展度、叶长、叶宽、叶面积等指标分别比传统水培生菜高11.37%、19.89%、23.10%、28.59%和44.42%,地上部鲜重、根鲜重、总鲜重等指标分别比其高68.06%、60.32%和66.01%.立管悬钵静止水培生菜的地上部鲜重、根鲜重、总鲜重分别比用地下水配制营养液栽培的生菜高4.28%、8.70%和5.36%.当地下水营养液浓度在1.5、2.0剂量时,立管悬钵静止水培方式在生菜形态指标、鲜重、叶绿素含量等指标的形成上表现出较强的缓冲能力.但是,立管悬钵静止水培对于营养液缺素情况的缓冲效果不明显.     

有机生态型无土栽培技术及其营养生理基础

以番茄为试材,介绍了应用消毒有机肥代替营养液的有机生态型无土栽培技术的方法与原理。1991～1994年的试验结果表明:与营养液栽培相比,有机生态型无土栽培方法可降低肥料成本、增加果实中还原糖和维生素C含量、降低有机酸含量;采用有机生态型无土栽培,在番茄的整个生长期间,基质中营养元素的供应水平与植株对营养元素的吸收要求一致,吸收氮、磷、钾的比例为N:P2O5:K2O=1:0.251:1.141;同时,有机生态型无土栽培对环境无污染。     

An empirical model to simulate sodium absorption in roses growing in a hydroponic system

Modelling nutrient absorption can contribute to the management of hi-tech cultivation systems in greenhouse horticultural production. Nevertheless, previous studies to understand the kinetics of nutrient absorption, rarely take into consideration the accumulation of salt ions in the nutrient solution. In this project we develop and validate an empirical model for sodium uptake concentration in hydroponic rose (Rosa spp. cv. Kardinal) production. Model development and validation was conducted using a series of experiments in both greenhouse and growth chamber conditions. The model framework takes into account plant developmental stage and external sodium concentration. While model calibration data were collected at levels of sodium up to 40 mol m³ NaCl as root environment salt concentration, model validation was carried out at lower ranges.The proposed model not only shows a high predictive capability, but also provides useful output parameters such as electrical conductivity, which is the main parameter currently monitored for managing nutrient solution in greenhouse cultivation. Incorporated as part of a larger DSS, our model can be used to improve nutrient solution management in production regions that do not have economically valid alternatives other than the use of poor quality (saline) irrigation water.     

不同营养液配方对阳台水培黄瓜的影响

以‘戴多星’黄瓜为试材,系统研究了7种不同营养液配方T1~T7对阳台水培黄瓜生长的影响,通过测定黄瓜的株高、茎粗、SPAD值、产量、可溶性固形物含量和维生素C等指标,初步筛选和评价出适合阳台水培黄瓜的最佳营养液配方。结果表明:使用T7营养液配方水培黄瓜可以显著提高叶面积,达到429.25 cm2;SPAD值增至47.08;结瓜数14个、单瓜质量65.08 g和单株产量889.34 g、维生素C含量145.68 mg·kg-1和可溶性固形物含量4.24%。与其他配方相比,T7增幅差异显著,可作为阳台上水培黄瓜的最佳营养液配方。     

氮磷钾缺素对水茄幼苗生长和生理特性的影响

以水茄(Solanum torvum Sw.)幼苗为材料,用溶液培养法诱导N、P、K缺素症,观察缺素症的形态特征并测定各缺素水茄的生长与生理差异,以期为水茄栽培的营养诊断和施肥提供理论依据。结果表明:水茄缺素症的表现时间和主要症状有差异,缺N症状表现最早,缺N、缺K处理对植株地上部影响最明显;水茄缺素处理的叶片数、全株干质量、根总体积均低于对照,根冠比均高于对照;缺N水茄老叶和嫩叶的叶绿素含量均极显著低于对照,缺P处理的嫩叶叶绿素含量则极显著高于对照;不同缺素处理水茄的根系活力之间差异极显著,缺N和缺P植株根系活力变弱,而缺K植株的根系活力变强,比对照极显著提高了44.34%。     

硝酸钙胁迫对黄瓜幼苗生长和生理特性的影响

以温室专用黄瓜品种"津春2号"和"津春4号"为试材,采用营养液水培法,研究了不同浓度Ca(NO_3)_2胁迫对营养液水培黄瓜幼苗生长、膜脂过氧化和有机渗调物质含量的影响,以期为耐盐黄瓜新品种选育及设施黄瓜抗盐栽培提供参考。结果表明:随Ca(NO_3)_2胁迫浓度提高,黄瓜幼苗的株高、茎粗、根长、叶片数、最大叶长、最大叶宽及植株干质量、鲜质量和含水量均不同程度降低,光合色素和可溶性蛋白质含量呈"增加-降低"的规律,质膜透性、丙二醛和脯氨酸含量显著增加。说明Ca(NO_3)_2胁迫通过渗透胁迫造成了细胞水分亏缺,并通过氧化胁迫破坏了细胞膜结构,严重抑制了黄瓜幼苗的生长,但供试的2个品种对Ca(NO_3)_2胁迫的耐性并没有明显差异。     

营养液浓度对水芹产量和品质的影响

营养液浓度直接影响着水培蔬菜的产量与品质。本试验研究不同浓度的营养液处理对水芹生长品质和产量的影响， 以筛选适宜温室水培水芹生长的营养液浓度。结果表明：随着营养液浓度的增加，水芹生物量、叶绿素含量、光合参数、总 黄酮、VC、可溶性蛋白含量等指标呈现先升高后降低的趋势，其中1.5 倍营养液浓度处理表现最佳，能够提高水芹整体品 质与产量。     

Behaviour of some pesticides in a nutrient-film and in a rock-wool system

Adsorption of ethoprophos, tetrachlorvinphos and etridiazole onto rock-wool was found to be much weaker than adsorption onto soils. The rates of transformation in water and in water plus rock-wool at 20°C were low. The concentration of etridiazole was measured in a nutrient-film system with recirculating nutrient solution. The decrease was rapid in the first few hours but was more gradual afterwards, to low values at 8 days after application. Etridiazole penetrated poorly into the lower part of a rock-wool system when the solution was trickled near the stem-base of the tomato plants.     

孔穴型式和营养液浓度对黄瓜潮汐式穴盘育苗效果的影响

为了筛选出黄瓜潮汐式穴盘育苗最适孔穴型式和营养液浓度,以黄瓜品种中农18号为试材,采用两种类型穴盘(常规、侧开口)和3种浓度(×1、×0.5、×0.25)营养液进行潮汐育苗试验,测定了幼苗矿质元素吸收积累量及表观形态指标等。结果表明:随着营养液浓度逐步提高,黄瓜幼苗矿质元素吸收积累量逐渐增加,N、P、K的吸收积累量增幅达102.6%~125.1%,并促进了叶片叶绿素合成和幼苗株高、茎粗、单株叶面积、地上部干鲜质量等表观参数指标优化。此外,常规穴盘育苗效果总体优于侧开口穴盘。最终,以壮苗指数为主要参考指标,筛选出最佳的孔穴型式与营养液浓度组合,即采用常规穴盘并灌溉完全Hoagland营养液。     

低氧胁迫对平邑甜茶根系活力及氮代谢相关酶活性的影响

 采用控制营养液溶氧浓度的方法,研究了低氧胁迫对平邑甜茶幼苗生物量、根系活力、根系呼吸速率以及氮代谢相关酶活性的影响。结果表明：低氧胁迫抑制了植株的生长,营养液溶氧浓度越低,抑制作用越明显;低氧处理前期根系呼吸速率也受到了明显地抑制,并且溶氧浓度越低抑制作用越强,但随处理时间的延长,抑制作用降低,而幼苗根系活力则先急剧升高后急剧下降;低氧胁迫诱导了硝酸还原酶（NR）和谷氨酰胺合酶（GS）的活性,溶氧浓度越低酶活性增加幅度越大;而对谷氨酸脱氢酶（NADH-GDH）的活性先抑制后促进。平邑甜茶可通过增加呼吸消耗、改变代谢途径来缓解低氧逆境伤害。     

Impact of grafting and rootstock on nutrient-to-water uptake ratios during the first month after planting of hydroponically grown tomato

Tomato plants (cv. Primadonna F₁), non-grafted, self-grafted, or grafted onto the commercial rootstocks ‘He-man’ and ‘Maxifort’, were grown in recirculating nutrient solution. The uptake concentrations (UCs), i.e. mean nutrient-to-water uptake ratios of N, P, K, Ca, Mg, Fe, Mn, Zn, Cu, and B, were estimated based either on depletion from the nutrient solution or on accumulation in the plant biomass. Grafting onto both commercial rootstocks increased the total plant biomass. Hetero-grafting also increased the leaf N, Ca, and Cu concentrations but decreased those of Mg and Fe in comparison with self- and non-grafted plants. The mean UCs of N, Ca, and Cu were higher in plants grafted onto both commercial rootstocks in comparison with self- and non-grafted plants. However, hetero-grafting also raised the UCs of P, Fe, Mn, and B, because of an increased deposition of these nutrients to the roots in comparison with self-rooted plants. The method used to estimate the UCs, i.e. nutrient removal from the recirculating nutrient solution vs. nutrient recovery from plant biomass per volume unit of transpired water, resulted in similar values for N, Ca, Zn, and Cu, but had a significant impact on those of P, K, Mg, Fe, Mn, and B.     

潮汐灌溉营养液浓度分段设定对番茄穴盘苗生长的影响

以中杂302为试材,将番茄穴盘苗生长发育分为5个阶段(Ⅰ:播种至出苗;Ⅱ:出苗至子叶平展;Ⅲ:子叶平展至二叶一心;Ⅳ:二叶一心至三叶一心;Ⅴ:三叶一心至四叶一心),分段设定9个营养液浓度组合,研究潮汐灌溉条件下营养液浓度分段设定对番茄穴盘苗生长发育、养分积累量及利用率的影响.结果表明:在第Ⅰ阶段,灌溉1.0×营养液,番...     

A porous stainless steel membrane system for extraterrestrial crop production

A system was developed in which nutrient flow to plant roots is controlled by a thin (0.98 or 1.18 mm) porous (0.2 or 0.5 microns) stainless steel sheet membrane. The flow of nutrient solution through the membrane is controlled by adjusting the relative negative pressure on the nutrient solution side of the membrane. Thus, the nutrient solution is contained by the membrane and cannot escape from the compartment even under microgravity conditions if the appropriate pressure gradient across the membrane is maintained. Plant roots grow directly on the top surface of the membrane and pull the nutrient solution through this membrane interface. The volume of nutrient solution required by this system for plant growth is relatively small, since the plenum, which contains the nutrient solution in contact with the membrane, needs only to be of sufficient size to provide for uniform flow to all parts of the membrane. Solution not passing through the membrane to the root zone is recirculated through a reservoir where pH and nutrient levels are controlled. The size of the solution reservoir depends on the sophistication of the replenishment system. The roots on the surface of the membrane are covered with a polyethylene film (white on top, black on bottom) to maintain a high relative humidity and also limit light to prevent algal growth. Seeds are sown directly on the stainless steel membrane under the holes in the polyethylene film that allow a pathway for the shoots.