Economic valuation and conservation: Do people vote for better preservation of Shadegan International Wetland?

Shadegan International Wetland (SIW) is a unique natural ecosystem with great national and international significance, designated under Ramsar Convention. Located in southern part of Iran, this wetland serves many functions. Among them the rich biodiversity, ecological, hydrological, and economic functions are the most important. Despite the great opportunities for sustainable development of this wetland, it is currently under serious threats from a diverse range of non-sustainable activities. Underestimating SIW’s non-market values in development decisions is a major reason for the conversion and excessive depletion of its resources. The aim of this study was therefore to estimate the economic benefit of SIW as a very useful instrument to reflect the values of this unique ecosystem to society members. A choice experiment (CE) survey was undertaken to estimate the value of different nonmarket attributes of SIW. In addition to the overall model, users and nonusers preferences were also estimated. Random parameter logit (RPL) model was employed to derive the marginal value of the respondents for different attributes of the nonmarket values of SIW. Results indicated the respondents’ positive preferences towards better conservation of SIW.     

Influence of Varieties,Irrigation and Weed Control Measures On Nutritional Status of Chickpea Grains

Gesunde Pflanzen - The effect of weed control in chickpea crop was assessed during 2011–12 and 2012-–13 in two-year experimentation at Ahmad Wala Research Station district Karak,...     

Chemical composition and larvicidal activities in vitro and in vivo of essential oils of Thymus vulgaris (L) and Lavandula angustifolia (Mill) against pine processionary moth Thaumetopoea pityocampa Den. & Schiff. in Ain Defla (Algeria)

Journal of Plant Diseases and Protection - Biological tests with Thymus vulgaris against both third and fifth instar larvae of Thaumetopoea pityocampa showed positive correlation between the used...     

Chitinolytic <Emphasis Type="Italic">Streptomyces griseorubens</Emphasis> E44G enhances the biocontrol efficacy against <Emphasis Type="Italic">Fusarium</Emphasis> wilt disease of tomato

Streptomyces griseorubens E44G is a chitinolytic bacterium isolated from cultivated soil in Saudi Arabia (a hot, arid climatic region). In vitro, antifungal potential of S. griseorubens E44G was assessed against the phytopathogenic fungus, Fusarium oxysporum f. sp. lycopersici (the causative agent of the Fusarium wilt disease of tomato). An inhibition zone of 24 mm was recorded. The chitinolytic activity of S. griseorubens E44G was proved when the colloidal chitin agar plate method was used. A thermostable chitinase enzyme of 45 kDa molecular weight was purified using gel filtration chromatography. The optimum activity was obtained at 60 °C and pH 5.5. The purified enzyme has shown a very pronounced activity against the phytopathogenic fungus, F. oxysporum. The molecular characterization of the chitinase gene indicated that it consists of 1218 bp encoding 407 amino acids. The phylogentic analysis based on the nucleotide DNA sequence and the deduced amino acids sequence showed high similarity percentages with other chitinases isolated from different Streptomyces species. In the field evaluation, application of both S. griseorubens E44G treatments significantly increased all tested growth and yield parameters and decreased the disease severity compared with the infected-untreated tomato plants suggesting potential as a biocontrol agent.     

Effect of wheat and rice straw biochar produced at different temperatures on maize growth and nutrient dynamics of a calcareous soil

The objective of this work was to study the effect of different biochar on alkaline calcareous soil, inherently low in soil organic carbon and fertility. Experiments were conducted in laboratory and greenhouse. Biochar was produced from wheat and rice straws at pyrolysis temperatures of 300°C, 400°C and 500°C (denoted as WSB300, WSB400, WSB500, RSB300, RSB400 and RSB500, respectively). In the first experiment, soil was incubated with biochar (1.0 % w/w) for up to 50 weeks. The results indicate that, WSB300 caused a significant decrease in soil pH and increased the CEC and nutrients (N, P and K) after 50 weeks of incubation. In the second experiment, maize plants were grown in pots containing calcareous soil amended with WSB and RSB for 60 days the results revealed that the application of WSB300 caused a significant increase in shoot (36%) and root (38%) dry matters over the respective control. Moreover, the highest nutrient concentrations (N and P) in shoot and root were observed with the WSB300 compared to other treatments. Therefore, it is concluded that application of wheat straw biochar produced at low temperature (WSB300) could be successfully used to improve soil properties and growth of plants in calcareous soils.     

Sources of Heavy Metals and Their Long-term Effects on Microbial C, N and P Relationships in Soil

The effects of heavy metals (Zn, Pb, and Cu) on microbial biomass C, N, and P were assessed in soils contaminated over a wide range by sewage sludge, exhaust dust deposition of a lead factory and river sediments of mining residues. Microbial biomass C, N, and P did not show any clear heavy metal effect related to soil dry weight. Also the ratios of microbial biomass C/N and biomass C/P remained unaffected by heavy metals. The ratios of microbial biomass C/soil organic C, biomass N/total N, and biomass P/total P were all negatively affected by increasing concentrations of Zn, Pb, and Cu as detected by a source-specific analysis of covariance using the different heavy metal fractions as covariate. Negative effects of Zn on the ratios microbial biomass C/soil organic C and biomass N/total N increased with increasing metal solubility in the order: (X-ray fluorescence analysis) XFA-detectable <HNO₃ <EDTA ?NH₄NO₃-extractable Zn. The Zn effects on the microbial biomass N/total N were always smaller than those on the microbial biomass C/soil organic C ratio. The same was true for all effects of the Pb and Cu fractions on these two ratios. For this reason, the deposition of highly soluble Zn and Pb by exhaust dust has the most negative effects, although sediments contained the maximum total burden of Zn and Pb. All fractions of Zn, Pb, and Cu had similar negative effects on the microbial biomass P/total P ratio, although the NH₄NO₃-extractable fraction again showed the most pronounced effects.     

INTERACTIONS BETWEEN COMMON BEAN GENOTYPES AND RHIZOBIA STRAINS ISOLATED FROM MOROCCAN SOILS FOR GROWTH,PHOSPHATASE AND PHYTASE ACTIVITIES UNDER PHOSPHORUS DEFICIENCY CONDITIONS

The improvement of common bean production requires the selection of effective rhizobia strains and Phaseolus vulgaris genotypes adapted to available soil phosphorus limitations. The interactions between bean genotypes and rhizobia were studied in hydroponic culture using six genotypes and four strains, CIAT899 as reference and three strains isolated from nodule of farmer's fields in the Marrakech region. The phosphorus (P) sub-deficiency caused a significant reduction on shoot biomass in some bean genotype-rhizobia combinations. Nodule biomass is significantly more reduced under P limitation for several combinations tested. Bean plants inoculated with these local rhizobial strains showed higher nodulation and an increase of nodules phytase and phosphatase activities under phosphorus sub-deficiency especially for RhM11 strain. It was concluded that the studied bean-rhizobia symbiosis differ in their adaptation to phosphorus sub-deficiency and the nodule phosphatases and phytases activities may constitute a strategy of nodulated bean plants to adapt their nitrogen fixation to P deficiency.     

Response of Sunflower to Sulfur Rate and Time of Application under Two Tillage Systems in a Silty Clay Soil of Dera Ismail Khan Pakistan

ABSTRACT

Sulfur (S) availability is a characteristic of conservation tillage. We studied the effects of S on sunflower yield and fatty acid profile under conventional and conservation tillage in silty clay soil of D.I. Khan, Pakistan. Conventional tillage consisted of disk plowing followed by tiller and rotavator, while conservation tillage comprises tiller and disc harrowing. Treatments comprise six sulfur levels (S₁ = 0, S₂ = 20 kg S ha^?1 at sowing, S₃ = 10 kg S ha^?1 at sowing +10 kg S ha^?1 25 days after sowing (DAS), S₄ = 40 kg S ha^?1 at sowing, S₅ = 20 kg S ha^?1 at sowing + 20 kg S ha^?1 25 DAS, and S₆ = 20 kg S ha^?1 at sowing + 10 kg S ha^?1 25 DAS + 10 kg S ha^?1 50 DAS) replicated thrice. After 2 years of experimentation, soil samples were collected (from 0 to 0.30 m depth) for organic matter (OM), total soil N (TSN), and available sulfur analysis. Conservation tillage significantly increased OM, TSN, and S contents in 0–0.30 m soil compared to conventional tillage. Likewise, sunflower plants showed higher achene yield, better fatty acid profile, and net economic returns in conservation tillage than in conventional tillage. Application of 20 kg S ha^?1 at sowing and 10 kg S ha^?1 at each 25 and 50 DAS recorded significantly higher achene yield, higher oil, and linoleic acid contents; however, oleic and oleic/linoleic ratio did not increase with higher S rates. Conservation tillage was effective in increasing OM, TSN, and available S besides increasing yield and economics in silty clay soil.