Environmental Sciences
Year:2007 | Volume:4 | Issue:4|Papers Count:9

Maize (Zea mays L.) is one of the most important and fast developing crops in Iran. A study of maize seedling emergence, phenology, dry matter partitioning, harvest index, silage fodder and grain yield was undertaken using plant growth promoting rhizobacteria (PGPR) as biofertilizing, including four strains of Azotobacter chroococcum , Azospirillum lipoferum , A. brasilense and Pseudomonas fluorescens . Late maturity single cross hybrids, SC704, SC700 and a promising single cross B73×K18 of maize were utilized in this study. Objectives of this study were to identify the most responsive hybrid and the effectiveness of PGPRs. A field experiments were conducted in 2004 and 2005. Treatments included hybrids seeds and a single inoculation by PGPRs and coinoculation by two and all PGPRs inoculants and control with no inoculation. Results revealed that application of PGPR increased final seedling emergence percentage, speed of emergence and grain filling period decreased length of seedling emergence and vegetative growth periods. At the same time PGPRs applications increased silage fodder yield and plant fresh weight and grain yield and grain yield per plant, biomass, grain dry weight and harvest index.These studies illustrated that SC700 and SC704 were the most productive hybrids for grain and fodder production respectively. The most effective PGPRs were the combination of all bacteria inoculants. Therefore, PGPRs applications could play considerable role in increasing yield and consequently development of maize cultivation.

Restoration is to decrease human impact on ecosystems, and let them to recover. In this method we can connect patches with corridors. Thus, to introduce an ecological restoration we considered shafarod watershed with 39800 ha, that is located in Gilan province. Corridor recognized as a liner element of landscape, which can connect patches. The objective of this research is to introduce a new method for ecological restoration of forest by using landscape ecology approach. At first we classify patches with Forman (1995) on basis of natural or man made. Then each patch on shafarod landscape was classified with, near to river or far from road, and with area, then each patch had one code that tell us the situation of road and river related to each patches.Patches with upper than 1 hectare are suitable for stepping-stone patches. In shafarod watershed among 683 patches with 36200ha, 56 patches with 228ha for restoration had been recognized and total area that these patches need to create corridors for restoration is about 62ha.

The background hydrochemical system, the pollution sources, and the different pollutants of ground water in the Izeh plain, north east of Khuzestan, were determined and spatial and temporal variations of pollutants were studied. Groundwater samples from thirty four wells, one piezometer, and one Qanat have been collected in three periods of 2001. The nitrate concentrations of ground water in the Izeh plain increase, continuously, as a result of agricultural activities. The major process that cause increasing of nitrate concentrations in ground water is leaching of application of inorganic manure on cultivated areas. The maximum concentrations of nitrate in ground water of Izeh plain occur in May then the concentrations decrease during dry season.Although bacteria's adsorb on sandy silt layer overlying Izeh alluvial aquifer but shallow ground water are polluted bacterially.

Nowadays, sewage sludge disposal is a great concern of wastewater treatment plants in both developed and developing countries. Land application of sewage sludge is still one of the most important disposal options in most countries. Although, land application of sludge allows the nutritional value of treated sludge to be used beneficially in agriculture, but pollutants and pathogenic organisms in sewage sludge can raise the health risk of human and animals. The aims of this study are 1) to investigate the applicability of dried sludge of Tehran WWTP's in agricultural activities according to U.S. EPA 40 CFR Part 503 regulations and, 2) to find a possible statistical relationship between parasite eggs, Fecal Coliform (FC) and Total Coliform (TC).Three wastewater treatment plants including "Shahrak-e-Gharb", "Shoosh and "Mahallati" were chosen in city of Tehran and the samples were collected during three seasons (fall, winter and spring (2006-7)). Parasite eggs, FC and TC of collected samples were examined using standard methods. The results showed that the average amounts of FC for sludge of Shahrak-e-gharb , Shoosh and Mahallati WWTP's were found to be 4.9 ×103, 3.7×103 and 1.21×104 MPN/g.DS, respectively. According to the data, the sludge of all these wastewater treatment plants is classified into Class B of EPA 40 CFR Part 503 regulations. Therefore, direct human exposure to Class B sludge would still pose a significant health risk and application of these sludges is restricted. In addition, strong statistical relationships were found between parasite eggs and Fecal Colifrom of the samples with the Pearson correlation factor of 0.989.

One of the principles of the international environmental law embodied in the Stockholm Declaration is sustainable utilization of territory. According to this principle, states enjoy sovereignty over their natural resources which is exerted with due regard to their environmental policies. This principle also envisages that activities performed under their jurisdiction or control should not cause any damage to the environment of other states or areas beyond their jurisdiction. This principle is recognized in international documents, arbitration awards and decisions of the International Court of Justice. In this article we study briefly this principle as it has been mentioned under these documents and decisions.

The long-term forecasting and monitoring of Climatological parameters depends on identification of all effective factors that are affects on this phenomenon. One of these parameters is the weather signal. These signals are the determinable and specific pattern and occur in the distinguished regions in the world, but its effects are worldwide. One of the famous signals is ENSO phenomenon, which have two phases. In this paper with using annual and seasonal correlations between Southern Oscillation Index (SOI) and rainfall data and also between Southern Oscillation Index (SOI) and temperature data, the effective amounts of ENSO phases on the differences of these factors was studied in the all regions of Khorasan province in I.R. of Iran, then for more comprehensive study the classification maps in relation of ENSO and variability of rainfall and temperature were drown. It was concluded that the mentioned parameter in the whole of the province especially in central and north strip have shown significant action to ENSO, in other word the average of temperature correlation indices are negative annually and seasonally ,it means when SOI amounts are increased the temperature in Khorasan province will be decreased. With regard to increasing the above weather parameters in all regions of Khorasan province at the time of ENSO's negative phases (El Nino condition) variation of temperature could be related to the changes of pattern of occurrences this phenomenon (ENSO) due to climatic change around the world.

The rice stem borer, Chilo suppressalis Walker, is the most important rice pest in north parts of Iran and survives the winter as diapausing mature larvae in rice stubble and weeds. To determine the strategy of hibernation and changes of cold hardiness, overwintering larvae were collected from a paddy field at Rice Research Institute in Rasht from October 2004 to March 2005. Because of hard winter in 2004 and snowfall about 2m on February no sampling was done on this month. The supercooling points (SCPs) of whole body of the larvae collected on October were - 18.8oC but it significantly increased to -12.4oC on November and did not change until snowfall on February. Thereafter, SCPs was raised to -8.2oC on March. There was more than 90% survival in the larvae collected from October to March, 24h after exposure to -10 and -15oC but the survival was increased from 30% on October to 80% on November and the following months, 24h after exposure at –20oC.Because of the increase of supercooling point in winter and endurance of temperaure below this point it is suggested that this pest to be a freezing tolerant insect in Iran and entered diapause from late November in the year of study.

Industrial Estate of Rasht is one of the oldest Industrial Estate of Iran in Guilan province .It was established before the Islamic republic of Iran's revolution in 1974. The Industrial Estate of Rasht that is the greatest active Industrial Estate in the province is located at 18- kilometer of western south side of Rasht city. In this article, solid waste management has been studied as one of the problems of this Industrial Estate. The method of this article has been on the basis of observation and completion of subjective questionnaires distributed among 61% of the active industrial units. Study of finding show that majority of industries, have a passive approach toward remarks of environment protection, absorption of environment experts and scientific management of Solid wastes. In this regard, only 13.4% of the units have environment experts, 14.9% of industrial units have taken an action for studying their solid wastes. For this reason, two industrial units have been able to select as Green unit in Guilan province. Metal and nonmetal mineral Industries groups have the most amount of industrial solid waste with 26.80% and 20.72% respectively, and Metal Industrial groups with 19% and textile industries with 15.23% have the most weight of House-hold solid wastes.About 4.45% of the units have recycled their solid wastes and 21.20% of them do the recycling together with other management activities such as source reduction, incineration and Sanitary Land fill. About 1.51% of industrial units have incinerated their Solid Wastes but no precise control is made on air pollution. In summary the industrial units under study in Industrial Estate of Rasht produce 3903.8 tons of industrial solid wastes per year and 217.2 tons of House-hold solid wastes per year.According to the obtained results, upon development of industrial activities in factories and increase of the number of staffs, the volume of produced solid wastes will increase in future. Accumulation of these wastes in the Industrial Estate will create undesirable environmental effects and more consumption of resources. By applying an integrated solid waste management system in Industrial Estate of Rasht, production of solid waste is decreased and increasing industrial development will be maintained.