NFT栽培槽槽底形状对生菜生产效果的影响

以生菜为试材，研究了NFT栽培槽不同槽底形状对生菜生产效果的影响。试验结果表明：NFT栽培槽不同波纹式槽底形状对生菜的生物积累量有显著影响，但对生菜的品质无显著影响，其中，以纵剖面是不等边三角形的波纹式槽底形状对生菜的植株开展度和产量的影响最为显著。在NFT栽培方式中，栽培槽底铺不铺无纺布对生菜产量有显著影响。综合生菜产量因子与商品性状，以［(6+14)×4］的纵剖面不等边波纹式栽培槽槽底形状最优。     

不同DFT装置对生菜产量和品质的影响

为经济解决DFT栽培中根际溶氧问题,试验设计了4种结构特点不同的DFT装置,以意大利耐抽苔生菜为试验对象,研究不同DFT装置对生菜产量和品质的影响.结果表明,循环浮板法(CFS)栽培能够稳定供给植株生长所需要的养分和氧气,生菜产量最高,品质较好;支撑浮板法(SFS)栽培虽然不能使营养液中的溶氧达到理想水平,但暴露在空气中的根系可以吸收空气中的氧气,植株生长良好,维生素C含量最高,硝酸盐含量最低,与其他3种处理的差异达极显著水平;浮板法(FS)和动态液位法(DSS)中生菜产量相对较低,要想合理地应用这两种栽培方式,还需要对其结构和系统设计中的某些参数进行修改和设定.综合生菜产量因子与商品性状,支撑浮板法是最适宜的DFT方式.     

不同DFT装置对生菜产量和品质的影响

为经济解决DFT栽培中根际溶氧问题，试验设计了4种结构特点不同的DFT装置，以意大利耐抽苔生菜为试验对象，研究不同DFT装置对生菜产量和品质的影响。结果表明，循环浮板法(CFS)栽培能够稳定供给植株生长所需要的养分和氧气，生菜产量最高，品质较好；支撑浮板法(SFS)栽培虽然不能使营养液中的溶氧达到理想水平，但暴露在空气中的根系可以吸收空气中的氧气，植株生长良好，维生素C含量最高，硝酸盐含量最低，与其他3种处理的差异达极显著水平；浮板法(FS)和动态液位法(DSS)中生菜产量相对较低，要想合理地应用这两种栽培方式，还需要对其结构和系统设计中的某些参数进行修改和设定。综合生菜产量因子与商品性状，支撑浮板法是最适宜的DFT方式。     

复式光滑或粗糙渠槽的流量比

复式渠槽和河道的过流能力还没有一个完全令人满意的估算方法,但已有大量的实验资料,包括复式渠槽小比例尺和大比例尺的试验资料、河道原型实测资料。现提出了两个关键的比率,即总流量比满槽流量、槽流量比滩流量,并从理论上分析了它的重要性,其适用性也在不同比例尺各种形状的光滑或均匀粗糙复式渠槽中得到了验证。复合断面总流至与满槽流量的比值,仅是断面几何形状的函数,而与底坡、比例尺的大小无关,槽流量与滩流量的比值,也与底坡、比例尺无关,但受滩地洪水横向坡降的影响。文中还对公式中与水深比有关的系数和指数作了估计。建议利用比值来预报复式均匀糙率渠糟流量的简单方法,随着相关资料的积累,对其它的情况,也可能适用。     

养殖尾水混合不同比例水溶肥种植水培生菜的综合效益评价

以“奶油生菜”为研究对象,将不同量的山崎配方水溶肥溶于工厂化养鱼尾水,配制成混合营养液,进行营养液膜栽培(NFT)水培生菜实验,以期筛选出最佳水肥配比,为实现工厂化养鱼尾水资源化利用提供理论依据。实验设置5个处理,分别为S1(123g水溶肥+150L养鱼尾水)、S2(98.4g水溶肥+150L养鱼尾水)、S3(73.8g水溶肥+150L养鱼尾水)、S4(49.2g水溶肥+150L养鱼尾水)、S5(24.6g水溶肥+150L养鱼尾水),以CK(123g水溶肥+150L清水)作为对照,探究不同处理对生菜产量和品质的影响。采用基于熵权法的TOPSIS综合效益评价模型分析确定最佳水肥配比参数。结果表明,混合营养液能提高生菜对水肥的吸收量,但随水溶肥浓度增加,生菜耗肥量呈先增大后减小的趋势;不同处理下生菜耗水耗肥量均低于CK处理,S1-S5处理相比CK处理分别节肥25.01%、19.15%、34.12%、51.89%和74.10%。混合营养液能有效促进生菜生长,但生菜各项生长指标均随水溶肥浓度上升呈先增大后减少的趋势,S2处理下生菜产量最高,为1.88kg·m^-2,相比CK...     

草莓种植槽立体栽培技术探讨

种植槽立体栽培草莓,能大幅提高密度、产量、品质,节本、增效。基于此,从红塔区正有草莓种植专业合作社种植槽立体栽培草莓的优势、管理技术、病虫害绿色防控等方面阐述草莓种植槽立体栽培技术,供广大草莓种植户参考。     

基质添加菌糠对几种蔬菜硝酸盐含量的影响

试验研究在栽培基质中添加不同比例的菌糠对蔬菜硝酸盐积累的影响,结果初步表明:(1)施用菌糠可以显著提高紫叶生菜、菠菜和菜心的产量,尤其是菜心,但过量施用会阻碍植株的生长。(2)施用菌糠可显著降低紫叶生菜、菜心和菠菜的硝酸盐含量,但过量施用反而使这些蔬菜更易在可食部分积累硝酸盐。(3)施用菌糠可显著降低紫叶生菜、菜心和菠菜的亚硝酸盐含量,但过量施用会导致可食部分亚硝酸盐含量的增加。(4)珍珠岩、草炭土、菌糠之比为4∶2∶4的混合基质配方是提高紫叶生菜、菜心和菠菜产量,降低可食部分硝酸盐含量的最佳栽培基质配方。     

各形态和浓度砷对生菜生长的影响试验

用营养液模拟土壤溶液栽培本地生菜,分别加入不同化学形态及不同浓度的砷,观察其对生菜生长量的影响,结果发现ＤＭＡ、Ａｓ（ Ⅲ） 毒性强于ＭＭＡ、Ａｓ（ Ⅴ） ;随有效砷浓度增加,生菜产量下降;砷对生菜鲜重和干重、地上和地下部分的影响存在差异;当培养液砷浓度超过受试植株的承受阈值时,生菜即表现为急性中毒死亡。     

弱光条件下光质和光周期对水培生菜生长与品质的影响

在弱光条件的人工光植物生长室中,设置两种不同红蓝光比例光质和两种不同光周期,水培盆栽红叶生菜（R）、绿叶生菜（G）和紫叶生菜（P）,采收后测定3种生菜的生物量指标以及抗氧化物、可溶性糖等营养品质指标,以研究弱光条件下光质和光周期对3种叶色水培生菜产量和品质的影响。结果表明：（1）生菜产量主要受光周期影响,营养品质指标受光质和光周期的综合影响。光照时间延长显著增加了3种生菜叶面积。绿叶生菜和红叶生菜单位叶面积鲜重在不同光质及光周期下无显著差异。紫叶生菜单位叶面积鲜重对光周期变化的反应则因光质环境而异。延长光周期使3种叶色生菜地上部鲜重提高一倍多,但3种生菜地上部鲜重受光质影响不显著。（2）延长光照时长对3种生菜营养品质的影响因光质而异。在红蓝1:2光质下,延长光照时长降低了绿叶生菜总酚和类黄酮相对含量以及抗坏血酸和可溶性蛋白含量,提高了红叶生菜花青素和可溶性糖含量,但降低了抗坏血酸和可溶性蛋白含量,紫叶生菜总酚相对含量得到提高,但抗坏血酸含量显著降低。在红蓝2:1光质下,延长光照时长显著提高了绿叶生菜总酚和类黄酮相对含量,抗坏血酸含量有所降低,红叶生菜总酚和类黄酮相对含量、抗坏血酸、可溶性糖和可溶性蛋白含量均显著降低,紫叶生菜总酚含量显著提高。说明在弱光条件下延长光照时长可以显著提高3种不同叶色生菜产量。在红蓝1:2光质下,延长光照时长使红叶生菜的花青素含量和可溶性糖含量得到显著提高。在红蓝2:1光质下,延长光照时长可以提高绿叶生菜和紫叶生菜营养品质。     

塑料大棚中不同灌水量下限对生菜生长和生理特性的影响

以两个散叶生菜品种弘农和绿领为材料,研究了塑料大棚栽培条件下不同田间持水量处理(70%～90%、60%～90%、50%～90%、40%～90%)对生菜产量、品质、叶绿素荧光参数和保护酶活性的影响.结果表明,以田间持水量的70%作为灌水量下限条件下生菜地上部鲜质量、叶片含水率、叶片数、叶面积均最大.随着灌水量下限的降低,生菜可溶性糖、可溶性蛋白含最逐渐增加,灌水量下限为田间持水量50%处理下的维牛素C含量显著岛于其他三个灌水量下限处理.对叶绿素荧光参数的分析表明,随着灌水量下限的降低,Fv/Fm(光系统Ⅱ最大光化学效率)、qP(光化学淬灭)、ΦpsⅡ(光系统Ⅱ电予传递量子效率)逐渐减小,而qN(非光化学淬灭)则逐渐增加.SOD(超氧化物岐化酶)和CAT(过氧化氢酶)活性,MDA(丙二醛)和Pro(脯氨酸)含量均随着灌水量下限的降低而逐渐增加.本试验的结果表明,70%灌水量下限处理下生菜的产量最高,综合不同灌水量下限处理对产量和品质的影响,60%的灌水量下限处理是最适合生菜生长的灌水处理.     

Nitrogen fixation by annual forage legumes and its contribution to succeeding wheat in the Ethiopian highlands

Soil fertility is declining in most agro‐ecosystems in sub‐Saharan Africa, and incorporation of forage legumes into production systems to utilize the nitrogen fixed by the legumes could alleviate the problem, if efficient nitrogen‐fixing legumes are used. The amounts of nitrogen fixed by Lablab, Medicago, Trifolium, and Vicia species and their contribution to the following wheat crop were estimated in field experiments on an Alfisol at Debre Zeit in the Ethiopian highlands. The amounts of nitrogen (N) fixed ranged from 40 kg N ha^‐1 for T. steudneri to 215 kg N ha^‐1 for L. purpureus. The increase in grain yields of wheat following the legumes ranged from 16% for T. steudneri to 71% for M. tranculata where no N fertilizer was applied to the wheat. Additional N fertilizer applied to wheat at 60 kg N ha^‐1 had no significant effects on wheat grain or straw DM andN yields. In another experiment, eight lablab treatments consisting of factorial combinations of two cultivars (Rongai and Highworth), two Rhizobium inoculation treatments (inoculated and uninoculated) and two times of harvest (for hay at 50% flowering and for seed at seed maturity), were compared on lablab forage production and N yield, and residual effects on two succeeding wheat crops. Inoculation had no significant effects on nodulation, shoot DM or N yields. Rongai had significantly higher shoot DM and N yields than Highworth. Lablab harvested at flowering had significantly higher shoot DM and N yields than lablab harvested at seed maturity. Grain yields of the first wheat crop following the various lablab crops were 93–125% higher than grain yields of the wheat following wheat (continuous wheat) where no N fertilizer was applied. Therefore, lablab is a potential forage crop for incorporation into cereal production systems to improve feed quality and to reduce dependence on N fertilizers for cereal production.     

NFT无土栽培营养液溶氧量的研究

本文阐述了在NFT系统上试验探讨营养液溶氧量与环境因子的相关关系,就如何改善溶氧供给,提出若干改进NFT设施设计的建议,如:适当加大贮液池;在贮液池上附设循环液的喷洒装置;适当扩大栽培床的槽腔;夏天采用低温的地下水配制贮液池中营养液,或降低温室(大棚)的气温。     

十年来中国无土栽培的进展

我国的无土栽培起步较晚,1975年只在温室内开始小面积生产,1989年全国已发展到8公顷。目前生产上采用的主要方式有袋培、槽培和少数营养液膜系统栽培。无土栽培所需要的设备和化肥已经全部国产化。现正在研究降低生产成本,有机肥和化肥混合使用,改进灌溉系统并提高生产效益。     

Effect of NO3 and NH4 concentrations in nutrient solution on yield and nitrate concentration in seasonally grown leaf lettuce

The effect of suboptimal supply of nitrogen (N) and of replacing nitrate in the nutrient solution with ammonia on growth, yield, and nitrate concentration in green and red leaf lettuce was evaluated over two seasons (autumn and spring) using multiple regression analysis. The plants were grown in a greenhouse on a Nutrient Film Technique (NFT) system. Nitrogen concentrations in the nutrient solution were either 3?mM or 12?mM, and the form of N was varied as follows: 100% NO₃, 50% NO₃?+?50% NH₄, and 100% NH₄. In both seasons, the biomass (fresh weight) of lettuce heads increased with increasing NO₃ concentrations and in autumn, NO₃ even at 1.5?mM was sufficient for high yield. However, head dry weight was affected neither by the season nor by changes in the composition of the nutrient solution. The concentration of NO₃ had no effect on root dry weight, but it decreased at higher concentrations of NH₄. The number of leaves increased as the ratio of NO₃ to NH₄ in the nutrient solution increased and was higher in autumn because of the longer growth period. Increasing the concentration of NO₃ in nutrient solution increased both total N and nitrate concentration in lettuce heads (dry weight) but decreased the concentration of total C. Also, leaf nitrate concentration was lower in spring than in autumn and decreased with increasing NH₄ concentration. Nitrogen utilization efficiency was maximum when NH₄ levels in the nutrient solution were either 0% or 50% irrespective of the season. Our results thus show that suboptimal N supply in autumn will not affect lettuce yield, and that nitrate concentration in leaves is lower when NH₄ concentrations in nutrient solution are higher and also much lower in red lettuce than in green lettuce.     

零排放循环流水水产养殖机械—细菌—草综合水处理系统研究

零排放技术是循环流水水产养殖实现可持续发展的关键之一，该文以机械—细菌—草综合水处理系统为基础进行零排放循环流水水产养殖，生产系统的两个养殖池(各1.325 m³水)共养殖淡水白鲳(Colossoma brachypomum)62尾(平均体重208.3±28.6 g，养殖密度4.87 kg/m³)。经过25 d的运行，养殖池NO^-₃-N、TAN(总氨氮)、TN(总氮)、TP(总磷)、COD(化学需氧量)、pH等水质指标基本维持稳定(p<0.05)，NO^-₂-N和SS(悬浮物)显著下降。在处理系统中，机械过滤器和生物滤器的大多数水质指标显著优于沉淀器沉淀区水质(p<0.05)。沉淀器沉淀区的高浓度污液定期(每天34.3 L)输送到植物滤器，间隔循环灌溉2.55 m² NFT培高羊茅(Festuca arundinacea Schreb.)，并定期(每4 d一次)回流重复利用。牧草的净化使水质发生了显著的改善(p<0.01)，NO^-₃-N、NO^-₂-N、SS的净化率超过90%，TN、TP的净化率超过85%，TAN和COD的净化率为45.2%和71.6%，此外，回流水的EC和pH显著高于污液，每次回流67.5±6.0L。淡水白鲳日增重4.55 g，饲料系数1.610。     

Performance of wick irrigation system using self-compensating troughs with substrates for lettuce production

Subirrigation systems in which water and nutrients are supplied to the substrate through wick strips for upward nutrient solution (NS) movement can be a feasible alternative to improve lettuce quality with low environmental pollution, enabling production with reduced labor and electricity or in regions with high air temperature. The objective of this study was to compare the performance of two wick irrigation systems using self-compensating troughs filled with either pine bark (WPB) or coconut coir (WCC) with nutrient film technique (NFT) hydroponic system for greenhouse lettuce production. The daily monitoring of electrical conductivity (EC) and pH allowed the experiment management according to the recommended values for optimal lettuce growth. The EC showed variation among troughs and salt accumulation in substrates, with WPB exhibiting two times greater EC than WCC (ranging from 0.95 to 7.57 and from 0.68 to 3.67 dS·m^?1, respectively), while the pH values were stable over time. The WCC promoted greater root length and shoot diameter, while WPB produced shorter plants compared to the other two treatments. NFT resulted in an 83% lower leaf area and 44% lower root volume than WPB and WCC. The fresh and dry shoot masses with NFT were 58% and 24% lower than with WPB and WCC, respectively. The fresh root mass was also reduced in NFT plants, which was 67% smaller than WCC and 59% smaller than WPB. Root dry mass of NFT was 35% lower than the average of WPB and WCC. Nitrate (NO₃)-nitrogen (N), ammonium (NH₄)-N, phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), boron (B), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) concentrations in plant shoot and root at the end of the experiment as well as the same nutrients, chloride, sodium, and bicarbonate concentrations in substrate and NS determined weekly differed among the treatments (P < 0.01). The EC and nutrient concentration in the substrates increased over time. The wick irrigation system with both substrates resulted in higher productivity than NFT, with higher yield and plant quality in WCC, indicating its feasibility as an alternative system for lettuce production in greenhouses. However, due to the salinity buildup, water and nutrition management needs to be optimized for self-compensating troughs to avoid an increase in substrate EC over time.     

Deployment of Sawdust as Substrate Medium in Hydroponically Grown Lettuce

In this study, lettuce plants were grown in sawdust (Saw) and/or perlite (Per) mixtures (sawdust; Saw:Per 75:25%; Saw:Per 50:50%; Saw:Per 25:75%; Perlite) and in Nutrient Film Technique (NFT), in an unheated greenhouse. Plants grown in NFT were taller with greater leaf area resulting in greater fresh weight. Sawdust addition reduced leaf length, leaf area and as a consequence the fresh weight but not the leaf number. However, leaf dry weight increased as sawdust content increased into the substrate. Leaf chlorophyll reduced but leaf fluoresces increased in perlite and NFT. High sawdust content (75% or 100%) reduced photosynthetic rates and stomatal conductance. Nutrient uptake [potassium (K), sodium (Na), phosphorus (P)] was the greatest in NFT treatment, while perlite and Saw:Per 25:75% increased elemental uptake (up to 74%) comparing with the remaining treatments. Leaf elemental analysis fluctuated among treatments. Thus, low content (i.e. 25%) of sawdust in perlite could improve inorganic substrate media properties.     

QUARTZ PORPHYRY TREATMENT ALTERS IRRIGATION WATER CHEMISTRY,AFFECTING HYDROPONIC VEGETABLE PRODUCTION

This study focused on using quartz porphyry (QP) as a water treatment to improve hydroponic production of komatsuna (Brassica rapa L. nothovar; Japanese mustard spinach). We compared the chemistries of the control and QP-treated nutrient solutions and found that magnesium (Mg²⁺) and calcium (Ca²⁺) concentrations increased linearly up to day 21 following sowing in both conditions, then declined slightly. The QP treatment reduced sodium (Na⁺) and chloride (Cl^?) concentrations for the whole cultivation period. In both the control and QP-treated solutions, nitrate (NO^? ₃) and sulfate (SO^2? ₄) showed the same trend to a daily increase. In spite of these similarities, however, komatsuna production was better with the QP-treated nutrient solution compared to control. Treatment with QP during cultivation in August–September reduced the harmful effects of Na⁺, chloride (Cl^?), nitrite (NO^? ₂), and SO^2? ₄ by reducing concentrations of these ions, possibly leading to decreased salinity and toxicity effects in the plants. Mineral concentrations during October–November differed from those of August/September, resulting in variation among the different growth parameters for komatsuna.     

下一代Internet发展综述——下一代Internet的产生和发展

本文论述了IPV6产生的社会原因,阐述了国外发达国家下一代Internet的发展状况和中国下一代Internet的发展状况及最新进展。     

Assessment of the effect of the climatic parameters on the distribution of the Al-Fe-humus horizons in the soils of the Russian planes

A comparative-ecological approach for studying the general regularities of soil ecology on the basis of geoinformation systems is suggested. It has been applied to analyze the distribution of Al-Fe-humus horizons. The quantitative climatic parameters of soils with Al-Fe-humus horizons have been estimated, and the relationships between them have been established. The applicability of this approach for assessing the general regularities of soil ecology is shown.