共查询到20条相似文献，搜索用时 15 毫秒
1.
Unfermented rooibos originates from the leaves and the stems of the indigenous South African plant, Aspalathus linearis, and it has been reported to have a higher content of flavonoids compared to that of fermented rooibos. The HPLC/UV method developed in our laboratory for the analysis of the fermented rooibos was applied to the quantitative characterization of the major flavonoids present in the unfermented rooibos. Main compounds determined were aspalathin (49.92 +/- 0.80 mg/g), isoorientin (3.57 +/- 0.18 mg/g), orientin (2.336 +/- 0. 049 mg/g), and rutin (1.69 +/- 0.14 mg/g), followed in order by isovitexin, vitexin, isoquercitrin and hyperoside, quercetin, luteolin and chrysoeryol. The identity of detected flavonoids was confirmed by comparing their retention times and UV spectra with those of corresponding standards. The total antioxidant activity (TAA) of the tea infusions was measured by the ABTS*+ radical cation decolorization assay. The TAA of unfermented rooibos (0.8 Trolox meq/g) resulted 2-fold higher than that of the fermented rooibos. When compared with different water infusions of Camellia sinensis (green and black tea), this TAA value was about 50% lower. 相似文献
2.
Joubert E Winterton P Britz TJ Gelderblom WC 《Journal of agricultural and food chemistry》2005,53(26):10260-10267
Unfermented rooibos tea is known to contain higher levels of total polyphenols and flavonoids than its fermented counterpart, making it the obvious choice for the preparation of flavonoid-enriched fractions. Evaluation of aqueous extracts and crude polyphenolic fractions of unfermented and fermented rooibos showed anti- and/or pro-oxidant activities, using a linoleic acid-Tween-buffer emulsion for lipid peroxidation and the deoxyribose degradation assay, based on a Fenton reaction model system containing FeCl3-EDTA and H2O2 for the generation of hydroxyl radicals. Except for the ethyl acetate fraction, with the highest total polyphenol (TP) content and offering the least protection presumably due to pro-oxidant activity, the inhibition of lipid peroxidation by the samples correlated moderately with their TP content in a linear relationship (r = 0.896, P < 0.01). Using the deoxyribose degradation assay, the pro-oxidant activity of the aqueous extracts and their crude polymeric fractions (0.1 mg/mL in the reaction mixture) was linear with respect to their dihydrochalcone (aspalathin and nothofagin) (r = 0.977, P = 0.023) and flavonoid (r = 0.971, P = 0.029) content. Pro-oxidant activity was demonstrated for pure aspalathin. Using the same assay, but with ascorbate added to regenerate Fe3+ to Fe2+, the aqueous extract and crude polymeric fraction of fermented rooibos displayed hydroxyl radical scavenging activity. Fermentation (i.e., oxidation) of rooibos decreased the pro-oxidant activity of aqueous extracts, which was contributed to a decrease in their dihydrochalcone content. The in vitro pro-oxidant activity displayed by flavonoid-enriched fractions of rooibos demonstrates that one must be aware of the potential adverse biological properties of potent antioxidant extracts utilized as dietary supplements. 相似文献
3.
蒸汽爆破预处理和微生物发酵对玉米秸秆降解率的影响 总被引：7，自引：2，他引：5
为了提高玉米秸秆的利用效率,首先对玉米秸秆进行蒸汽爆破预处理（压力2.5 Mpa,维压200 s）,然后再进行米曲霉发酵,研究物理和生物学处理对秸秆成分及相关酶活变化的影响。结果表明,蒸汽爆破使秸秆中纤维素、半纤维素和木质素的降解率分别达到8.47%、50.45% 和36.65% （p＜0.05）。爆破预处理的秸秆再经米曲霉发酵6 d后,秸秆中纤维素和半纤维素的降解率分别为27.89%和64.80% （p＜0.05）,发酵秸秆中的滤纸酶、羧甲基纤维素酶、淀粉酶和蛋白酶活力分别达到335.10、1138.92、1954.20和201.99 U/g。爆破预处理后进行米曲霉发酵,对于提高玉米秸秆的降解率具有非常重要的意义。 相似文献
4.
为探究米根霉发酵米糠的最佳条件,本研究采用过热蒸汽对米糠作稳定化处理,以米根霉为菌种发酵稳定化米糠,以米糠可溶性膳食纤维(SDF)得率为指标,并对此条件下发酵米糠的体外益生活性进行评价。结果表明,过热蒸汽稳定米糠最佳条件为160℃、2 min,此条件下脂肪酶失活率为88.01%;甜香型米根霉发酵米糠的最佳条件为:以甜香型米根霉为发酵菌种,料液比1:2.25、接种量0.7%、发酵温度35℃、发酵时间24 h,此条件下SDF得率为5.83%,比未发酵米糠提高了近一半;与未发酵米糠相比,经甜香型米根霉发酵后的米糠,可有效促进双歧杆菌(对数值6.85)和乳酸杆菌(对数值5.23)的增殖;总短链脂肪酸含量提高37.30%,肠道益生活性显著增强(P<0.05)。本研究结果为改善米糠功能特性提供了依据,对今后米糠在发酵方面的应用具有一定的指导意义。 相似文献
5.
通过盆栽模拟试验研究了硒对水稻生长、碳氮代谢以及产量的影响。结果表明,施硒显著提高了水稻叶片、根及大米中硒的含量,硒对水稻株高影响不大,但显著提高了水稻的秸秆鲜重以及籽粒产量;施硒能提高水稻叶片的叶绿素含量,对光合速率具有提升作用,增强了水稻对光合碳的同化能力,从而提升了植株根及叶片的可溶性糖含量;施硒显著提高了水稻叶片及根中谷氨酸脱氢酶、谷氨酰胺合成酶、谷氨酸合成酶以及硝酸还原酶的活性,增强了水稻对氮素的同化代谢能力;硒对碳氮代谢产物可溶性蛋白影响不大,但是在显著提高水稻叶片氮含量的基础上降低了中间代谢产物游离氨基酸的含量,说明硒促进了碳氮代谢中间产物游离氨基酸向大分子有机含氮化合物的转化。试验结果说明,硒对产量的提升作用可能是通过影响碳氮代谢过程来实现的。 相似文献
6.
Frias J Song YS Martínez-Villaluenga C González de Mejia E Vidal-Valverde C 《Journal of agricultural and food chemistry》2008,56(1):99-105
Food allergy has become a public health problem that continues to challenge both the public and the food industry. The objective of this research was the detection and quantification of the major human allergenic soy proteins and to study the reduction in immunoreactivity and improvement of amino acid content after fermentation of soybean flour. Fermentation was carried out in the solid state of cracked seeds inoculated with Aspergillus oryzae, Rhizopus oryzae, and Bacillus subtilis and in the liquid state of milled soybean flours fermented naturally by microorganisms present only in the seeds or by inoculation with Lactobacillus plantarum. ELISA and Western blot were used to quantify IgE antibody response, and HPLC was used to identify and quantify total amino acids. L. plantarum fermented soy flour showed the highest reduction in IgE immunoreactivity (96-99%) depending upon the sensitivity of the plasma used. Among the solid fermented products, the lowest reduction in immunoreactivity was obtained when mold strains, R. oryzae and A. oryzae, were used (66 and 68%, respectively, for human plasma 97.5 kUA/L). Among the solid fermented products, those inoculated with B. subtilis yielded a 81 and 86% reduction in immunoreactivity against both human plasma 97.5 IgE kUA/L and human pooled plasma samples, respectively. When soybean was subjected to liquid fermentation, most of the total amino acids increased significantly ( p < or = 0.05). In solid fermentation with R. oryzae, only Ala and Thr content improved. Fermentation can decrease soy immunoreactivity, and there is potential of developing nutritious hypoallergenic soy products. 相似文献
7.
连续施用鸡粪对露地黄瓜产量、品质和土壤性质的影响 总被引：2，自引：0，他引：2
8.
Fernandez-Orozco R Frias J Muñoz R Zielinski H Piskula MK Kozlowska H Vidal-Valverde C 《Journal of agricultural and food chemistry》2007,55(22):8972-8979
The effect of fermentation on the antioxidant compounds [vitamins C and E, total phenolic compounds (TPC), and reduced glutathione (GSH)], and antioxidant capacity [superoxide anion scavenging activity (SOD-like activity), peroxyl radical-trapping capacity (PRTC), inhibition of phosphatidylcholine (PC) peroxidation, and Trolox equivalent antioxidant capacity (TEAC)] of soybean (Glycine max cv. Merit) was studied. Fermentation was carried out in solid state in cracked seeds inoculated with Aspergillus oryzae, Rhizopus oryzae, Bacillus subtilis, and Lactobacillus plantarum and in liquid state either in cracked seeds or milled soybean flours fermented naturally by only the microorganisms present in the seeds or by inoculation with L. plantarum. Vitamin C was not detected in the studied samples. Fermentation caused a decrease in vitamin E activity, except when cracked seed was fermented with A. oryzae, R. oryzae, or B. subtilis that increased 31, 30, and 89%, respectively. Fermentation produced an increase in TPC content and did not affect or reduce the GSH content. Fermentation decreased SOD-like activity drastically, while PRTC increased except when it was carried out naturally in cracked seed. TEAC values rose sharply when soybeans were fermented with B. subtilis. Processed soybean extracts inhibited PC peroxidation in comparison with the control assay. On the basis of the results obtained, the relative contributions of vitamin E, TPC, and GSH to antioxidant capacity were calculated and results showed a very high TPC contribution and a low contribution of GSH and vitamin E activity. Optimum results for functional soybean flours were achieved when fermentation was carried out with B. subtilis inoculum. 相似文献
9.
Ahmad Bybordi Saaed Saadat Parisa Zargaripour 《Archives of Agronomy and Soil Science》2018,64(4):520-530
Considering the importance of onion and its cultivation in saline soils, a two-year experiment was carried out to investigate the effects of soil applied zeolite and foliar application of selenium (Se) and silicon (Si) on onion yield, qualitative traits and physiological attributes, under salinity stress. An experiment was performed at three-way factorial design with three replications as follows: zeolite at three levels (0, 4 and 8 ton ha-1), Se at three levels (0, 0.5 and 1 kg ha-1) and Si at three levels (0, 200 and 400 kg ha-1). The results indicated that the effect of year was significant on all studied traits except for soluble solids, bulb nitrogen, leaf sodium and potassium, chlorophyll content and peroxidase activity. Number of small-sized bulbs decreased with increasing zeolite, Se and Si application. Dry matter, soluble solids, nitrogen content, nitrate concentration as well as protein content significantly increased due to zeolite, Se and Si application. Leaf sodium content and enzyme activity decreased due to zeolite, Se and Si application. Overall, 8 ton ha-1 zeolite along with 1 kg ha-1 Se and 400 kg ha-1 Si caused the maximum onion yield and qualitative and physiologic traits including soluble solids, potassium, protein, chlorophyll and photosynthesis . 相似文献
10.
稻草高茬-紫云英联合还田改善土壤肥力提高作物产量 总被引：24，自引：4，他引：20
研究旨在探讨稻草留高茬套种绿肥、稻草-绿肥联合还田下的生产及土壤肥力特征,为南方稻区综合利用稻草和绿肥提供理论及技术支撑。2012—2016年设置定位试验,研究高茬稻草-绿肥联合还田下的绿肥和水稻产量、土壤碳氮库活性及其他养分特征。试验包括5个处理:冬闲+稻草不还田(CK),冬闲+稻草全量还田(RS),冬种紫云英+稻草不还田(MV),冬种紫云英+稻草低茬全量还田(MV+LRS),冬种紫云英+稻草高茬全量还田(MV+HRS),各处理施用等量化肥。结果表明:稻草-绿肥联合还田提高绿肥产草量及其含氮量,与MV相比,分别增加了13.1%和6.8%(MV+LRS)、32.2%和5.2%(MV+HRS);增加水稻产量,以MV+HRS处理最高,4 a平均产量较RS、MV增加556.8和412.8 kg/hm2。2013和2015年,MV+HRS处理水稻产量高于MV+LRS。稻草-绿肥联合还田培肥地力效果明显,土壤有机质、全氮含量均比CK、RS和MV增加;且联合还田下有效养分提升更为全面。与稻草和绿肥单独应用相比,稻草-绿肥联合还田还能提升土壤微生物量氮及可溶性有机碳氮含量。可见,稻草-绿肥联合还田能够改善绿肥生长、提高水稻产量、提升土壤肥力;其中,高茬稻草与绿肥联合还田下的紫云英和水稻产量最高,土壤肥力也优于低茬处理,是综合利用稻草和绿肥资源的较好方式。 相似文献
11.
本文以萝卜（品种为枇杷叶）为研究对象，采用田间试验探究了无秸秆还田（CK），秸秆粉碎还田（SC）、过腹还田（SM）、炭化还田（SB）、粉碎+过腹还田（SC+SM）、粉碎+炭化还田（SC+SB）、过腹+炭化还田（SM+SB）对土壤理化性质和萝卜产量及品质的影响。结果表明，6种秸秆还田方式均显著提高了土壤有机质和全氮含量，但对土壤速效钾含量的影响不同，其中SC、SM和SB 3种还田方式不影响土壤速效钾含量，而SC+SM、SC+SB和SM+SB 3种秸秆组合还田方式显著提高了土壤速效钾含量；不同秸秆还田方式对萝卜生物量和叶片叶绿素相对含量（SPAD值）的影响不同，除SC+SM处理萝卜肉质根鲜物质量、叶片SPAD值显著低于对照外，其他秸秆还田处理萝卜肉质根鲜物重量和叶片SPAD值均显著高于对照；秸秆还田处理萝卜品质较对照显著提升，6种秸秆还田处理萝卜维生素C、可溶性糖、总酚、类黄酮含量均显著高于对照，且不同还田方式间无差异；秸秆还田还显著降低了萝卜硝酸盐含量，提高了可溶性蛋白含量，其中SC+SM、SC+SB和SM+SB 3种秸秆组合还田处理表现突出，硝酸盐含量降低36.04%~40.63%，可溶性蛋白含量提升41.70%~56.11%； SC、SM和SB处理次之，硝酸盐含量降低15.15%~22.58%，可溶性蛋白含量提升16.61%~25.11%； 6种秸秆还田方式下萝卜铁离子还原能力（FRAP）显著高于对照，但1，1-二苯基-2-三硝基苯肼自由基清除能力（DPPH）不同，其中SM、SC+SM、SC+SB和SM+SB处理萝卜DPPH值显著高于对照，SC和SB处理萝卜DPPH值与对照接近。综上所述，除SC+SM处理降低了萝卜产量外，SC、SM、SB、SC+SB、SM+SB等5个秸秆还田处理均提高了土壤肥力和作物产量、改善了产品品质，其中SC+SB、SM+SB在降低萝卜硝酸盐含量方面表现尤为突出。考虑到操作的难易程度，常规蔬菜生产中建议采用秸秆粉碎还田、过腹还田、炭化还田3种方式，种植根菜、叶菜等硝酸盐高积累型蔬菜时建议采用粉碎+炭化还田、过腹+炭化还田2种秸秆组合还田模式。 相似文献
12.
不同小麦秸秆还田量对水稻生长、土壤微生物生物量及酶活性的影响 总被引：2，自引：0，他引：2
通过大田试验研究了不同小麦秸秆还田量（0、1500、3000、4500、6000kg.hm-2）对水稻生长、土壤微生物量及酶活性的影响。结果表明：秸秆还田后,水稻分蘖数、株高、SPAD及干物质积累量均高于秸秆不还田（对照）,但是未全部达到显著性差异;50%秸秆还田处理增产效果最显著（P〈0.05）,与对照相比,理论增产10.2%,实际增产9.0%;秸秆还田处理显著增加了土壤全氮和速效氮含量,对土壤有机质、有效磷和速效钾含量影响不显著;50%秸秆还田处理对微生物量碳、氮的提高作用最明显（P〈0.05）,分别较对照提高46.0%和90.0%;25%和50%秸秆还田显著提高了土壤脲酶活性（P〈0.05）;25%、50%和75%秸秆还田土壤过氧化氢酶活性较对照提高9.3%、12.1%和8.5%（P〈0.05）;与对照相比,50%秸秆还田土壤蔗糖酶活性提高20.3%（P〈0.05）。鉴于秸秆还田对作物产量和土壤肥力的长期效应以及对土壤微生物生理代谢影响的复杂性,合理秸秆还田量的选择还需进行长期定位试验研究。 相似文献
13.
再生水加氯对滴灌系统堵塞及番茄产量与氮素吸收的影响 总被引：4，自引：1，他引：3
加氯处理是防止再生水滴灌系统生物和化学堵塞的常用方法,但有关加氯处理对作物生长影响的研究尚不充分。通过在日光温室内的田间试验,研究了加氯浓度和加氯频率对再生水滴灌灌水器堵塞特性、番茄产量和品质的影响;建立了土壤硝态氮含量随土壤电导率、含水率和温度变化的多元回归模型,分析了加氯处理对根区土壤硝态氮变化动态和氮素吸收的影响。结果表明,加氯处理能够有效防止再生水滴灌引起的灌水器流量降低;再生水滴灌增加了硝态氮在土壤表层（15 cm深度）的累积,促进了作物对氮素的吸收;加氯处理使植株吸氮量明显降低,加剧了硝态氮在土壤表层的累积,累积量随着加氯浓度和加氯频率的增大而增大;再生水滴灌的番茄产量略高于地下水滴灌,而再生水加氯处理会使产量有所降低;再生水滴灌使番茄口感指标（可溶性糖和水溶性总酸）显著提高、营养指标（Vc含量和可溶性固形物）显著降低,加氯处理能够有效缓解营养指标的降低趋势。采用浓度低于50 mg/L、频率低于两周1次的加氯处理对作物的氮素吸收有一定的抑制作用,但不会对作物生长造成明显不利影响。 相似文献
14.
Joubert E Viljoen M De Beer D Manley M 《Journal of agricultural and food chemistry》2009,57(10):4204-4211
The phenolic quality of commercial South African fermented rooibos iced teas in terms of aspalathin, iso-orientin, and orientin contents in comparison to a "cup of tea" was shown to be inferior. The role of the different manufacturing stages of powdered extract used in iced tea formulation and, more specifically, the impact of pasteurization and sterilization on the color and phenolic content of the beverage, were assessed as potential causes of its inferior phenolic quality. Aspalathin and its corresponding flavones, iso-orientin and orientin, were found to be present at all stages of the powdered extract production process. Spray-drying did not significantly (P ≥ 0.05) alter the aspalathin, iso-orientin, or orientin content of concentrates. Simulated normal-temperature sterilization (NTS at 121 °C/15 min) and high-temperature sterilization (HTS at 135 °C/4 min), but not necessarily pasteurization (93 °C/30 min), significantly (P < 0.05) reduced the aspalathin, iso-orientin, and orientin contents of different iced tea formulations. Heat-induced losses of iso-orientin and orientin were lower than those for aspalathin. Conversion of aspalathin to the flavones is implicated. The addition of ascorbic acid and/or citric acid to the base iced tea formulation containing only rooibos extract and sugar proved to be beneficial, especially for the retention of aspalathin. Browning, that is, absorbance at 420 nm, was significantly (P < 0.05) increased in the base formulation. In the case of the formulations also containing ascorbic acid and/or citric acid, absorbance remained unchanged or decreased when subjected to NTS and HTS treatments. This was attributed to removal of brown polymers from solution as the pH values of these formulations were lower than that of the base formulation. 相似文献
15.
Joubert E Richards ES Merwe JD De Beer D Manley M Gelderblom WC 《Journal of agricultural and food chemistry》2008,56(3):954-963
The in vitro antioxidant activity of aqueous extracts prepared from four Cyclopia spp. (unfermented and fermented) was assessed using radical (ABTS *+) scavenging, ferric ion reduction, and inhibition of Fe2+-induced microsomal lipid peroxidation as criteria. Aqueous extracts of unfermented and fermented Aspalathus linearis (rooibos) and Camellia sinensis teas (green, oolong, and black) were included as reference samples. Qualitative and quantitative differences in phenolic composition were demonstrated for the Cyclopia spp. The xanthone glycoside, a.k.a. mangiferin, was the major monomeric polyphenol present in the Cyclopia extracts, with both unfermented and fermented C. genistoides extracts containing the highest quantities. Fermentation resulted in a significant reduction in extract yields and their total polyphenolic and individual polyphenol contents. Unfermented plant material should preferentially be used for preparation of extracts, as fermentation significantly ( P < 0.05) lowered antioxidant activity of all species, except in the case of C. genistoides, where the ability to inhibit lipid peroxidation was not affected. Unfermented plant material also retained the highest concentration of mangiferin. Overall, extracts of unfermented Cyclopia were either of similar or lower antioxidant activity as compared to the other teas. However, the presence of high levels of mangiferin merits the use of Cyclopia spp. and, in particular, C. genistoides, as an alternative herbal tea and potential dietary supplement. 相似文献
16.
Influence of ammonium nitrate on the growth and straw decomposition of higher fungi 1. Nine species of higher fungi were investigated in order to study the influence of increasing NH4NO3 amounts on mycelial growth, the decomposition of straw substrates, the induction of fruiting bodies and the pH value of the substrates. 2. Increasing ammonium nitrate concentrations in the substrate clearly inhibited mycelial growth of two species (Stropharia rugosoannulata and Flammulina velutipes) whereas the others were not visibly affected. 3. Ammonium nitrate in the substrate led to different substrate decomposition patterns, depending on the fungal species used. The decomposition rates of Pleurotus salmoneo stramineus and Pleurotus eryngii decreased at all N-concentration levels. The decomposition rates of Lentinus edodes and Pleurotus sp. ?Florida”? were stimulated only at the lowest N-concentration level. Flammulina velutipes, Stropharia rugosoannula ta, Agrocybe aegerita, Kuehneromyces mutabilis and Ganoderma applanatum showed enhanced decomposition rates over the whole N-concentration range. 4. The induction and yield of fruiting bodies were also influenced by addition of ammonium nitrate. Low levels of ammonium nitrate stimulated fruiting body formation and yield of Agrocybe aegerita. Fructification of Lentinus edodes was delayed and the yield of fruiting bodies decreased at all N-concentration levels. At the given experimental conditions most of the investigated fungi did not fructify o r developed only primordia. 5. Addition of ammonium nitrate to the sterile substrate caused a decrease in pH. A further decrease in pH was observed after colonization of the substrate by fungi. 相似文献
17.
不同地面覆盖对土壤性状和秋播大蒜产量及品质的影响 总被引：2，自引：0，他引：2
为探究秋播大蒜适宜的地面覆盖类型及其对大蒜产量的影响机制,从而为地面覆盖在大蒜高产高效栽培中的应用提供理论依据,以‘麻江红蒜’为试验材料,以不覆盖处理为对照,分别设置白色地膜、黑色地膜、银灰色地膜、1～2 cm和3～4 cm稻草、1～2 cm和3～4 cm稻壳共7种地面覆盖处理,分析不同处理对土壤含水量、温度和酶活性以及大蒜产量和品质的影响。结果表明:地面覆盖处理均可提高0～10 cm土层的含水量,而对10～20 cm土层的含水量影响不显著;3种地膜覆盖处理可不同程度地提高土壤温度,其中以白色地膜的增温效果最好,而稻草和稻壳覆盖处理的土壤温度与对照间差异不显著;不同处理均不同程度地提高了土壤酶活性,其中脲酶活性以白色地膜和1～2 cm稻草覆盖处理最高,酸性磷酸酶活性以白色地膜和银灰色地膜覆盖处理最高,蔗糖酶活性以白色地膜覆盖处理最高。与对照相比,白色地膜和黑色地膜覆盖处理可显著促进大蒜的植株生长,蒜薹产量和鳞茎鲜重产量均以白色地膜覆盖处理最高(367.63 kg/667m~2和653.57 kg/667m~2),黑色地膜覆盖处理次之(287.73 kg/667m~2和363.80 kg/667m~2),两者显著高于对照及其他处理;鳞茎品质总体上以白色地膜覆盖处理最好,与对照相比,其可溶性糖(192.1mg/g)、可溶性蛋白(23.67 mg/g)和大蒜素(5.13 mg/g)含量均显著提高。综合分析认为:地膜覆盖可以改善土壤含水量和温度,稻草和稻壳覆盖仅提高了土壤含水量,但不同处理均可提高土壤酶活性,促进大蒜产量和品质的提高,以白色地膜覆盖的效果最好,黑色地膜覆盖次之。 相似文献
18.
《Journal of plant nutrition》2013,36(10):2243-2259
ABSTRACT Compost significantly enhanced strawberry (Fragaria × ananassa Duch.) plant growth and fruit quality when used as a soil supplement. Adding half strength of Peter nutrient solution (50% fertilizer) to a mixture of 50% soil plus 50% compost was very effective in significantly increasing plant dry weight to approximately double that of controls (without compost), fruit yield by more than 70%, and fruit size by 15% compared to controls in the two strawberry cultivars (“Allstar” and “Honeoye”). Compost and fertilizer also significantly enhanced leaf chlorophyll content. Nitrate reductase activity significantly increased in leaves and roots with the greatest increases when using 50% soil plus 50% compost. Strawberry plants grown with compost had significantly higher levels of nitrogen (N) and potassium (K), but lower levels of manganese (Mn), iron (Fe), molybdenum (Mo), and nickel (Ni) in fruit of both “Allstar” and “Honeoye”. Adding compost to the soil mix did not change zinc (Zn) and cadmium (Cd) levels. Use of compost also significantly increased levels of organic acids (malic and citric acid), sugars (fructose, glucose, and total sugars), soluble solids content, and titratable acidity content in both cultivars. The results indicate that the use of compost can reduce the amount of fertilizer required for optimum strawberry plant growth. 相似文献
19.
秸秆批式和半连续式发酵物料浓度对沼气产率的影响 总被引：2，自引：5，他引：2
为比较秸秆批式发酵和半连续发酵工艺的产沼气效果,以水稻秸秆为单一发酵底物,开展了室内中温批式发酵和半连续发酵对比试验,以容积产气率和原料产气率为特征指标,研究不同料液浓度对秸秆批式和半连续发酵产沼气的影响,以期获得秸秆沼气工程适宜的运行参数。结果表明,批式发酵容积产气率随着TS浓度的增加而增加,但增幅逐渐减少;与静态批式发酵相比,间歇搅拌有助于提高批式发酵容积产气率,特别对高TS浓度处理容积产气率的提升效果更加明显;而半连续进料条件下更有利于高TS浓度处理容积产气率的提高,但各处理原料产气率均随着固物滞留时间(solid retention time,SRT)缩短而逐渐降低。综合考虑产气情况及工程应用实际,建议秸秆批式发酵底物质量分数不超过8%,而半连续发酵TS质量分数8%时SRT设计为20 d(容积产气率1.00 m3/(m3·d)),若发酵TS质量分数6%时,SRT设计为15 d,容积产气率0.75 m3/(m3·d),该运行参数为秸秆沼气工程发展提供了理论依据。 相似文献
20.
补充灌溉、氮素营养与秸秆覆盖对冬小麦生长及产量的影响研究 总被引：5，自引：4，他引：5
大田试验研究补充灌水、施N肥与秸秆覆盖对冬小麦根系和地上部生长、产量及其构成因子的影响结果表明 ,施N肥对冬小麦生长发育和产量的效应最明显 ,单独覆盖秸秆或补充灌水基本无效甚至出现副作用。施用N肥和秸秆覆盖可促进冬小麦根系发育和地上部生物量累积。肥料供应充足时覆盖秸秆对冬小麦根系的作用与水分状况有关 ,土壤水分胁迫下秸秆覆盖效果不明显 ,此时施用N肥甚至出现一定负效应。水分充足与否 ,施N肥和秸秆覆盖均对冬小麦产量的形成有一定协同效应 ,补充灌溉与施用N肥和秸秆覆盖配合处理小麦产量最高。 相似文献