Suitability of wood fiber substrates for production of vegetable transplants II.: The effect of wood fiber substrates and their volume weights on the growth of tomato transplants

The influence of wood fiber substrates (WFS) and their volume weights (VW) on the growth of tomato transplants (Lycopersicon lycopersicum (L.) Karst. ex Farw.) were examined. No significant differences were observed for the absolute and relative growth rate of tomato transplants cultivated in WFS as compared to white peat (WP). Particularly in WFS plants showed a well developed root system. When the tomato transplants were cultivated in spring increases of VW led to a reduction of root growth, but no significant differences were observed for other plant parameters. In summer differences between weakly and strongly compacted substrate treatments for fresh mass of leaf and stem for both WFS were found. The coarse WFS also showed a significant difference in leaf area for these two treatments. Weakly compressed substrate had a faster decrease of matric potential in summer.WFS are suitable for cultivation of vegetable transplants and are a good alternative for peat-based substrates. When filling containers, moderate compression of WFS is recommended.     

Physical properties of media for container-grown crops. I. New Zealand peats and wood wastes

Physical properties of New Zealand peats from 5 sources and of wood wastes, bark and sawdust were evaluated in relation to container-grown crops. For comparative purposes, Irish peat was included. All the peats had adequate air space (AS), but the Springhill peat and New Zealand Forest Service bark and sawdust had a particularly high AS (35–38%). Easily available water (EAW) was also adequate in all peats. New Zealand Forest Service bark and sawdust had inadequate easily available water (EAW, 10–12%), but grinding the bark increased this property. All the peats had similar water-buffering capacity (WBC) with the Irish peat having the highest value. The wood waste materials had inadequate WBC. Total porosity was generally adequate in all materials studied and was highest in Springhill peat. The bulk density (BD) was closely related to degree of decomposition (r = 0.95***) and also inversely related to AS and total porosity (r = −0.82* and r = −0.65, respectively).     

Effects of conifer wood biochar as a substrate component on ornamental performance,photosynthetic activity,and mineral composition of potted Rosa rugosa

A greenhouse experiment was conducted to assess the performance of biochar obtained from pyrolysis of conifer wood as a substrate component for growing potted Rosa rugosa plants. Rose plants were grown with different mixtures of sphagnum peat and biochar (100% peat, 75% peat–25% biochar, 50% peat–50% biochar, 25% peat–75% biochar; v:v). Increasing the biochar content from 25% to 75% increased the air content, bulk density, electrical conductivity, and K and Na concentration in the substrates. The addition of 25% biochar to the substrate showed promising potential for R. rugosa when compared with 100% peat given the similar growth performance, water-use efficiency, and ornamental quality (number of flowers and leaf colour). The Ca and Na concentrations in leaves and roots as well as the Mg content in roots increased as the biochar percentage in the substrate increased, whereas an opposite trend was observed for P and K concentrations. The best performance and ornamental quality of R. rugosa grown with 100% peat and 75% peat–25% biochar compared with 50 and 75% biochar treatments were attributed to a higher degree of photosynthesis, Soil Plant Analysis Development index, and pigment content. Overall, adding 25% of conifer wood biochar as a substrate component could be applied for economic purposes without detrimental effects on the yield and quality of potted roses.     

Physical and hydraulic properties of baked ceramic aggregates used for plant growth medium.

Baked ceramic aggregates (fritted clay, arcillite) have been used for plant research both on the ground and in microgravity. Optimal control of water and air within the root zone in any gravity environment depends on physical and hydraulic properties of the aggregate, which were evaluated for 0.25-1-mm and 1-2-mm particle size distributions. The maximum bulk densities obtained by any packing technique were 0.68 and 0.64 g cm-3 for 0.25-1-mm and 1-2-mm particles, respectively. Wettable porosity obtained by infiltration with water was approximately 65%, substantially lower than total porosity of approximately 74%. Aggregate of both particle sizes exhibited a bimodal pore size distribution consisting of inter-aggregate macropores and intra-aggregate micropores, with the transition from macro- to microporosity beginning at volumetric water content of approximately 36% to 39%. For inter-aggregate water contents that support optimal plant growth there is 45% change in water content that occurs over a relatively small matric suction range of 0-20 cm H2O for 0.25-1-mm and 0 to -10 cm H2O for 1-2-mm aggregate. Hysteresis is substantial between draining and wetting aggregate, which results in as much as a approximately 10% to 20% difference in volumetric water content for a given matric potential. Hydraulic conductivity was approximately an order of magnitude higher for 1-2-mm than for 0.25-1-mm aggregate until significant drainage of the inter-aggregate pore space occurred. The large change in water content for a relatively small change in matric potential suggests that significant differences in water retention may be observed in microgravity as compared to earth.     

Influence of paclobutrazol and substrate on daily evapotranspiration of potted geranium

The application of plant growth regulators and the use of different culture media are common practices in potted ornamental crops. We report the results of a study to evaluate the effect of two substrates (peat moss or coconut fiber) and spraying 30 ppm paclobutrazol (PAC) on water resource management of zonal geranium (Pelargonium × hortorum L.H. Bailey) seedlings growing in a greenhouse during spring–summer. Growth, water consumption, leaching, evapotranspiration rate (ET), water use efficiency (WUE) and leaf water potential were determined. Plant growth was greater in peat moss (peat) than in coconut fiber (coconut), while the use of PAC decreased plant growth in both substrates, although more markedly in peat. Coconut produced a higher leaching fraction than peat in both PAC-treated plants and non-treated plants, although PAC application increased the leaching fraction in both substrates. Water consumption was lower in coconut than in peat and decreased in response to PAC. Peat was more effective at improving the water-use efficiency and increased the electrical conductivity in the leachate, while PAC decreased the latter in this same substrate. Daily ET showed a maximum of 200 mL/pot in peat and a minimum of 60 mL/pot in the coconut-PAC treatment. During the experimental period, accumulated ET values were higher in peat than in coconut, while the application of PAC reduced the value in peat but increased it in coconut. The evolution of ET per hour during the day showed that the highest rate (23 mL/h) was registered at midday in peat, while about 90% of ET occurred between 10 and 18 h in all treatments. When a cycle of water stress and recovery was applied, the peat induced the highest ET values of all treatments during the first days of drought, but the lowest ET after a week of drought. PAC modified this response, favoring a more balanced behavior of ET, although after the second cycle of drought this effect disappeared. Based on these results, the best strategy in normal irrigation conditions would be to use coconut fiber and not apply PAC, because this provides plants of excellent commercial quality with low water consumption. In plants at moderate water deficit PAC played a more important role than the substrate, improving the water status of plants with both substrates used. However, in the face of severe water stress the effect of PAC disappeared and peat acted as a better substrate than coconut fiber.     

蚯蚓粪基质在西瓜穴盘育苗中的应用研究

通过对蚯蚓粪理化性质的测定及其与草炭的对比,探讨了蚯蚓粪作为育苗基质的可行性;以蚯蚓粪为主要原料配合不同体积比的蛭石作为育苗基质,研究了复合基质对西瓜种子萌发及幼苗生长发育的影响。结果表明:与草炭相比,蚯蚓粪具有容重较大、孔隙度和持水力较小,高磷、钾含量和低氮含量等特性;3:1(v:v)蚯蚓粪复合基质育苗效果最佳,既提高了西瓜种子出苗率,又促进了幼苗生长发育,与对照相比,根体积、全株干重、壮苗指数分别增加了129．17％、22．95％、21．18％。     

Evolution of organic matter and drainages in wood fibre and coconut fibre substrates

New organic substrates have been introduced in hydroponic culture in order to substitute peat, because is a non-renewable resource, and in less rockwool or perlite due to their problematical recycling. The objective of this work is to evaluate the evolution of two renewable organic substrates, wood fibre (WF) and coconut fibre (CF) throughout one cultivation cycle. Two trials were set up, one with and a second one without crop. Volume, pH and EC of the input solution and the drainage solution were measured in both trials. In the trial without crop the content of NO₃⁻, Cl⁻, (SO₄)²⁻,Ca²⁺, Mg²⁺, Na⁺, P and K⁺ was also determined. Physico-chemical characterization of the substrates was determined at the beginning and at the end of the trials. In order to know the loss of organic matter (OM), the dry matter content of the substrates was determined at the beginning and at the end of both trials. It has been observed that in both substrates retention of elements like NO₃⁻, Ca²⁺, P and Mg²⁺ occurs. In the study of the physico-chemical properties, it has been observed that the air capacity decreases considerably in both substrates in the trial with crop, especially in the CF, as well as a greater reduction of the C/N rate and percentage of OM. The data of organic matter loosed shows that in the trial with crop both substrates have lost more OM and this loss is slightly superior in CF. Therefore it is important to consider the possible retention of nutrients in the organic substrates to optimise cultivation management, as well as their degradability, which influences on the physico-chemical properties throughout the crop cycle.     

不同基质配比对乌桕容器苗矿质元素和非结构性碳水化合物的影响

为了探讨乌桕容器苗在不同基质配比下生长情况，通过分析各个指标的变化揭示其生长规律。以苗圃土、泥炭、珍珠岩为基质原料，按不同体积配比，研究不同基质配比对乌桕容器苗矿质元素浓度和非结构性碳水化合物浓度的影响，筛选适宜乌桕苗的基质类型。结果表明：(1)矿质元素方面，D1(90%泥炭+10%珍珠岩)全氮、全磷、全钾、全碳含量最高，分别为1.17%、0.46%、6.09 mg/g、16.47%,D2(70%泥炭+30%珍珠岩)次之。(2)非结构性碳水化合物方面，D1可溶性糖、淀粉浓度最高，分别为0.55%、2.54%,D2次之，CK(100%苗圃土)最低。综上所述，D1(90%泥炭+10%珍珠岩)基质最适宜乌桕容器苗的培育。     

Retention of nutrients by peats and wood wastes

The retention and release of major nutrients by New Zealand peats and wood wastes was studied over 24 weeks in an incubation experiment. Irish sphagnum peat was included for comparison. The treatments consisted of fertilized and unfertilized materials. The samples were extracted with water using a 1 : 1.5 (v/v) ratio. Retention of N was low for all peats, but noticeably high for bark and wood shavings after 3 weeks. At 24 weeks, the peats retained less than 20%, while the wood wastes retained 35–68% of the applied N. There was little or no release of N by any material. Retention of P was also low for N.Z. peats (except Cambridge), although not as low as for Irish peat, but again high for bark and wood slavings. Retention of K was higher for peats than for wood wastes. Wood wastes contain more water-soluble K than peat.     

Morpho-physiological plant quality when biochar and vermicompost are used as growing media replacement in urban horticulture

Peat moss is the most used soilless substrate in the production of container plants in floriculture. Nevertheless, the drainage of peat bogs due to the peat extraction has increased the necessity of seeking products that could replace the peat that is used in plant production. Therefore, a comparative study was conducted to evaluate the effect of a biochar (B) - vermicompost (V) mixture, as a partial substitute for peat-based substrates, on the morpho-physiological characteristics of ornamental plants. Different blends containing B and V were compared to a baseline peat-based substrate (S) as control in the cultivation of two ornamental bedding plant species that are widely used in urban areas: geranium (Pelargonium peltatum) and petunia (Petunia hybrida). Plant growth and physiological parameters were assessed. Results showed that it is possible to grow container plants of these two species with commercial quality, using a peat-based substrate mixed with biochar and/or vermicompost (up to 30% V and 12% B). Plants in these substrates showed a similar or enhanced physiological response to those grown in the control using commercial peat-based substrate.     

泥炭基质对黄瓜生长潜能及其与抗病相关酶系的影响

利用泥炭基质和重迎茬土壤(CK)进行黄瓜栽培试验,测定不同基质对黄瓜株高、茎粗、根长鲜重等生长指标及对枯萎病发生情况的影响。结果表明:泥炭栽培的瓜苗在根长及株高上较对照差异显著,侧根量比对照明显增多;泥炭培养基能有效减少苗期猝倒病及枯萎病的发生;泥炭栽培的黄瓜单株产量明显高于对照;泥炭处理的黄瓜PAL、CAT、SOD酶活比同期对照高出33.05%～62.25%、12.56%～43.79%、13.09%～72.82%。说明泥炭培养基对黄瓜表现出良好的促生及抗病作用。     

不同基质配比对马铃薯微型薯产量的影响

在防虫网棚内,以马铃薯品种费乌瑞它的脱毒苗为试材,采用随机区组试验设计,研究了玉米秸秆、蛭石、草炭不同基质配比对马铃薯脱毒种苗成活率、单株结薯数、单株薯质量等指标的影响。试验结果表明,采用玉米秸秆∶草炭∶蛭石=25∶25∶50（体积比）的基质配比效果较好,脱毒种苗成活率高、单株结薯数较多、单薯质量大、大薯率高。     

Hydraulic characteristics of composted pig manure,perlite, and mixtures of them,and their impact on cucumber grown on bags

Composted pig manure (CPM), unmixed or in mixture with perlite, was evaluated as growing medium based on both physical characteristics and agronomic performance. The physical properties were determined in CPM, perlite (0.5–2.5 mm), and their 75:25, 50:50 and 25:75 mixtures by volume. It was found that unmixed CPM has a higher bulk density (BD) than perlite, a slightly lower air space at a suction of 10 cm, and a markedly higher content in easily available water (EAW), although the water content at a suction of 10 cm is the same in the two media. Mixing CPM with perlite by 50:50 seems to increase the actual water content and decrease the actual air content at container capacity, while the BD and the EAW score intermediate to those in the unmixed constituents. Simulation of the relative hydraulic conductivity (K_r) indicates a sharp decrease in the unsaturated hydraulic conductivity (K) of CPM, perlite and their mixtures as the media suction increases. The differences in the decrease rate of K_r between the tested substrates are rather small, with the most and least steep decrease being observed in perlite and the mixture by 50:50, respectively. The agronomic performance of CPM was assessed by growing greenhouse cucumber in bags filled with perlite up to 20 cm in height, CPM up to 10 or 20 cm in height, and their mixture by 50:50 up to the same heights as CPM. A media height of 10 cm in the bag resulted in appreciably higher yields than a height of 20 cm, regardless of the type of the substrate, while the latter had no significant effect on yield. This effect of media height was ascribed to the steep decrease in K, which was minimized in all media at higher suction levels than 10 cm, thereby severely restricting water availability in their upper layers (10–20 cm) when their height in the bag was 20 cm.     

The effects of irrigation on the establishment and yield of lettuce and leek transplants raised in peat blocks

The establishment and yield of lettuce and leeks were not reduced by transplanting dry (—0.06 to —0.09 MPa) as compared to saturated peat blocks (3.2 cm cube), provided irrigation was applied immediately after transplanting during the summer. When irrigation was withheld until eight days after transplanting the marketable yield of lettuce was reduced by 30% and 38% when transplanted in saturated and in dry blocks respectively. These reductions were due to reduced survival during establishment and to the more extensive trimming required to produce marketable heads rather than to a reduction in total fresh weight per plant at maturity. The marketable yield of leeks was reduced by 16% and 24% when saturated and dry blocks respectively were transplanted without irrigation, the reduction being largely due to a lower mean shoot weight. Measurements of block and soil water after transplanting suggested that even when the soil was irrigated immediately after transplanting, it was urmble to supply water directly to the blocks for more than a few days.     

不同基质和育苗方式对新铁炮百合幼苗素质的影响

以新铁炮百合为试材,比较了不同基质和育苗方式对新铁炮百合幼苗的生长和移栽及成花的影响.结果表明,草炭是最适合新铁炮百合幼苗培育的基质;以草炭为基质、采用穴盘育苗,可以提高新铁炮百合幼苗的质量、移栽质量和成花率.     

不同栽培基质对草莓植株营养生长的影响

以蛭石、草炭和珍珠岩为基质材料,研究不同配比的基质处理对草莓植株的成活率、株高、株茎粗、地上部及根部的鲜重及干重的影响,并对基质物理特性、pH和电导率进行分析.结果表明:不同基质处理都适合草莓栽培,以处理Ⅰ草炭+珍珠岩(2∶1)表现最好.     

不同覆土处理对双孢蘑菇产量和品质的影响

分析了泥炭与田泥分别以1：3、1：1、3：1的比例混合,以及纯泥炭作为覆土材料,并以常用的田泥稻壳土的覆土材料作为对照,研究了不同覆土的理化性质对双孢蘑菇产量和品质的影响。结果表明泥炭的持水率高、孔隙度大、电导率高、容重轻、含氮量高,这些特性有利于双孢蘑菇的生长,因此纯泥炭作为覆土时产量最高,随着添加田泥比例的升高,容重升高,其他参数降低,双孢蘑菇的产量有所降低,泥炭和田泥以1：1的比例混合时产量和对照没有显著差异,且在双孢蘑菇的品质方面也优于对照,作为覆土材料较为经济。     

Yield of greenhouse-grown tomato in substrates containing coir and parboiled rice or burnt rice hulls

Substrate components produced in the sub-tropics or tropics were combined in various proportions as substrates for the greenhouse production of ‘Big Beef’ tomato. Coir was mixed with parboiled rice hulls (PBH) or burnt rice hulls (BRH) at 0, 25, 50, 75, or 100% volume. Fruit fresh weights at equal proportions of BRH or PBH in coir were similar, with the greatest fruit yields achieved with 50 to 100% coir (0 to 50% PBH or BRH). Compared to 100% coir, PBH in coir decreased substrate container capacity and increased air porosity, while BRH in coir increased container capacity and decreased the air porosity. Pre-plant fertilisation of the PBH + coir substrates (superphosphate, gypsum, trace elements, calcium nitrate, and surfactant) increased fruit yield significantly. Substrates containing 50 to 100% coir with BRH or PBH yielded greater fruit fresh weights than was achieved in in 70% BRH + 30% gravel (a typical substrate used in the Dominican Republic), and reusing the 70% BRH + 30% gravel led to a 36% increase in fruit fresh weight. Fruit fresh weights in 100% coir or 75% coir plus 25% PBH or BRH were similar to those achieved in a commercial peat-lite. Herein we report on substrates made from tropical components that perform similarly to a peat-based substrate in the production of greenhouse-grown tomatoes.     

蚓粪复合育苗基质对黄瓜幼苗生长的影响

以蚓粪、腐熟中药渣、泥炭、蛭石、珍珠岩为原料,将不同原料按照不同比例复配成4种育苗基质。选取市场上销售的育苗基质作为对照(CK),研究不同比例复配的蚓粪育苗基质对黄瓜苗期生长的影响。研究结果表明,基质D培育的黄瓜幼苗在植株鲜质量、茎粗、根长、根表面积、根体积方面均较其他配比的育苗基质育苗效果好,可推荐作为黄瓜育苗的专用型有机营养基质。     

热处理对华北落叶松人工林木材力学性能和颜色的影响研究

以华北落叶松人工林木材作为研究对象,采用热空气进行热处理,分析不同温度(140℃、160℃、180℃、200℃)对华北落叶松木材的力学性能和表面颜色的影响。研究结果表明,在力学性能方面,随着热处理温度的升高,华北落叶松人工林木材的抗弯弹性模量(MOE)和抗弯强度(MOR)均降低,热处理温度越高降幅越大;而顺纹抗压强度(CS)先升高后降低,且热处理温度对抗弯强度影响比抗弯弹性模量大。在表面颜色方面,热处理材的明度值L^*、红绿轴色品指数a^*和黄蓝轴色品指数b^*均小于未处理材,且随着温度的升高呈逐渐降低趋势,热处理后木材表面颜色进一步变暗,随着热处理温度升高,色相差ΔH^*和总体色差ΔE^*增加且增幅逐渐增大,但饱和度差ΔC^*降低。