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11.
Effects of water table management on soil salinity and alfalfa yield in a semi-arid climate 总被引:2,自引:0,他引:2
Hamideh Noory Abdol-Majid Liaghat Mohamad Reza Chaichi Masoud Parsinejad 《Irrigation Science》2009,27(5):401-407
A lysimeter experiment was conducted to investigate the effect of water table management (WTM) on distribution of soil salinity
and annual alfalfa (Medicago scutellata) yield. Subirrigations with three levels of water table namely, 0.5 (WT0.5), 0.7 (WT0.7), and 1.0 m (WT1.0) and a free drainage
(FD) conventional irrigation treatment were selected for this study. All treatments were arranged in a complete randomized
block design with three replicates. The results of this study indicated that the average soil electrical conductivity of the
saturated extract (ECe) in the root zone gradually increased and exceeded the designated crop threshold value (4 dS/m) after
the first forage harvest in subirrigated lysimeters. A higher salt accumulation was observed at the WT0.5 treatment. The average
dry matter yield of annual alfalfa in WT0.5 and WT0.7 treatments was found to be 52 and 73% higher compared with the control
treatment, respectively. 相似文献
12.
H. M. S. Al Ubeed M. C. Bowyer J.B. Golding 《The Journal of Horticultural Science and Biotechnology》2019,94(5):620-626
Hydrogen sulphide (H2S) inhibits senescence in harvested fruit and vegetables but presents logistical, safety and regulatory issues to become a commercial treatment. D-cysteine and L-cysteine are semi-essential amino acids that are metabolised to hydrogen sulphide by plant tissues albeit by different pathways. This paper examines the effect of cysteine on postharvest senescence of three green leafy vegetables. Spraying pak choy leaves with 10 mmol D-cysteine, L-cysteine or DL-cysteine inhibited leaf senescence through a delayed loss of green colour expressed as market life, reduced respiration rate and reduced ethylene production. The beneficial effects of cysteine were similar to those achieved by fumigation with hydrogen sulphide. L-cysteine sprays on parsley and peppermint leaves also showed reduced leaf colour loss and respiration compared to untreated leaves. Cysteine, either as the racemate or individual enantiomers, is considered to have commercial potential for green leafy vegetables as it provides the beneficial effect of hydrogen sulphide but should be easier to register for commercial use due to the GRAS status of L-cysteine. 相似文献
13.
Ahlem Zrig Jorge F. S. Ferreira Foued Hamouda Taieb Tounekti Samy Selim Soad Al Jaouni 《Arid Land Research and Management》2019,33(3):297-320
Salinity reduces plant biomass and may lead to death when severe. To cope with the negative effects of this stress, plant species present specific physiological or biochemical responses. In this work, we hypothesized that spraying salt-stressed thyme leaves with K+ and Ca2+ could mitigate the negative effects of salinity on plant growth and metabolism. To test this hypothesis, we grew thyme plants under salinity stress for two and four weeks before applying foliar sprays. Also, to test the effect of stress relief, treated plants were allowed two weeks of recovery after four weeks of salt stress. In general, after two and four weeks of salinity stress, the leaf fresh weight of thyme plants was reduced by 31 and 43%, respectively. Salinity also decreased the relative water content, water, and osmotic potentials and led to ion imbalances and nutrient deficiencies. Salinity altered concentration of some essential oils, but leaf antioxidant contents remained fairly stable, except for a significant increase for plants under NaCl?+?KCl two weeks after treatment. Our results indicated that stressed plants accumulated significantly more soluble sugars and amino acids in comparison with the control. Foliar sprays with KCl and CaCl2 reversed the negative effects of salinity on plant biomass and induced the accumulations of compatible solutes. Moreover, concentrations of some essential oils and gallic acid increased in sprayed plants, but these effects were dependent on the type and duration of the treatment. Overall, spraying leaves with K+ and Ca2+ was able to mitigate salinity stress in Thymus vulgaris even during the recovery period. 相似文献
14.
Khadija M. Zadeh I. M. Inuwa Reza Arjmandi Azman Hassan M. Almaadeed Zurina Mohamad P. Noorunnisa Khanam 《Fibers and Polymers》2017,18(7):1330-1335
This work investigated the effects of date palm leaf fiber (DPLF) content on the thermal and tensile properties; and morphology of compatibilized polyolefin ternary blend. Recycled polyolefin ternary blend consisting of low density polyethylene (RLDPE), high density polyethylene (RHDPE) and polypropylene (RPP) were fabricated at different parts per hundred resin (phr) of DPLF. Maleic anhydride grafted polyethylene (MAPE) was used as compatibilizer to enhance the adhesion between filler and polymer matrix. The composites were prepared using melt extrusion and tests samples were produced via injection molding process. Thermal conductivity results showed that as much as 11 % reduction in thermal conductivity was achieved with the incorporation of 30 phr DPLF. Highest tensile strength was observed with the incorporation of 10 phr DPLF. The elongation at break was reduced with the addition of DPLF due to impediment of chain mobility by the fillers. Initial degradation temperature increased with the addition of DPLF. Hence, it is concluded that DPLF can be used to develop green and thermally insulating composites. It is hoped that the present results will stimulate further studies on the thermally insulative materials based on natural fibers reinforced polymer composites for applications in the building industries. 相似文献
15.
Md Abdul Wahab Sk Ahmad‐Al‐Nahid Nesar Ahmed Mohammad M Haque Mahmudul Karim 《Aquaculture Research》2012,43(7):970-983
Giant river prawn (Macrobrachium rosenbergii) farming plays an important role in the economy of Bangladesh. Presently, it is cultured in around 50 000 ha area with total annual production of 23 240 t. Traditional extensive prawn farming has been expanding over the last three decades through the introduction and adoption of improved culture systems, such as culture of prawn‐carps, prawn‐shrimp‐fish and prawn‐fish‐rice as concurrent and rotational systems. Efforts for the development of improved techniques on broodstock management, seed production and rearing and grow‐out of prawn have been made over the last decade. The outcomes are low‐cost feed for broodstock, production of post‐larvae in net cages (hapa), all‐male prawn culture, periphyton based prawn‐tilapia culture, C/N based prawn culture, organic prawn farming, prawn‐mola culture and prawn‐carp‐mola polyculture. Despite the development of culture technologies, a number of challenges for sustainable development of prawn farming need to be overcome to realize the potentials of this promising sector. Good aquaculture practises at all levels and application of measures for quality control and food safety would ensure sustainable development of prawn farming in Bangladesh. 相似文献
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18.
Elghazali M Wasfi IA Al Katheeri NA Hadi AA Hussein MM 《Journal of veterinary pharmacology and therapeutics》2002,25(1):43-48
The pharmacokinetics of etamiphylline were determined after an intramuscular (i.m.) dose of 3.5 mg/kg body weight in six healthy camels. Furthermore, the metabolites and drug detection time were evaluated. The data obtained median and (range) were as follows: the terminal elimination half-life (t(1/2 beta), h) was 3.04 (2.03-3.62); apparent total body clearance (Cl/F, L/h/kg) was 1.27 (0.74-2.99); the apparent volume of distribution at steady state (V(ss)/F, L/kg) was 4.94 (3.57-12.54); and renal clearance (Cl(r), L/h/kg) determined in two camels was 0.005 and 0.004, respectively. The detection time of etamiphylline in urine after an i.m. dose of 3.5 mg/kg body weight ranged between 12 and 13 days. Three etamiphylline metabolites were tentatively identified in camels urine: The first one desethyletamiphylline was the main metabolite and resulted from N-deethylation of etamiphylline had a molecular weight of 251, and was detected in urine for about 13-14 days. Theophylline (molecular weight 180) was the second metabolite and resulted from ring N-dealkylation of etamiphylline. It was present in small amounts and was detected for about 5 h after drug administration in urine. The third metabolite, possibly resulted from demethylation of etamiphylline, had a molecular weight of m/z 265, and was present in small amounts and was detected in urine for about 5 h after drug administration. 相似文献
19.
加拿大安达略省家禽生产者对死禽处理通常有以下几种方法:选择经认证的死畜禽处理公司,坑埋,焚烧,堆肥.本文描述了使用堆肥法成功堆肥家禽屠体的一些关键因素. 堆肥是一个狭长的可被生物降解的有机物质堆,有很大的表面积以便氧气良好地渗透.堆肥通过需氧微生物分解生物有机物质制成一个稳定的、类似土壤的物质,称为腐殖质.为了刺激微生物快速降解,有必要给这些生长增殖的微生物提供最理想的环境. 相似文献
20.
Analysis of the ethyl acetate extract of the aerials parts of Podocalyx loranthoides led to the isolation of I 7, II 4'-dimethylamentoflavone (1) and II 4'-methylamentoflavone (2). Compound (1) gave a moderate effect against Leishmania mexicana promastigotes. 相似文献