مجله مدیریت اراضی
سال نهم شماره 2 (پاییز و زمستان 1400)

Increasing concentrations of greenhouse gases such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in the atmosphere and the consequent climate change have irreversible effects on the environment and human health. Greenhouse gases in the soil are produced by microbial activity, root respiration, chemical decomposition, and heterotrophic respiration of organisms; the carbon flux from the soil in the form of carbon dioxide is caused by respiration and other activities of soil organisms, nitrous oxide is produced by nitrification and denitrification processes, and methane is produced by microbial methanogenesis under anaerobic conditions. This is while various environmental and managerial factors might affect their concentrations in the soil. Proper management of agricultural soils offers a significant potential to reduce greenhouse emissions. For instance, crop rotation, cover crop farming, conservation tillage, crop residues retention, and avoiding plant residue burning or removal serve as appropriate management practices to reduce carbon dioxide emission. Strategies employed to mitigate nitrous oxide emission include better nitrogen management, well-planned application of nitrogen fertilizers only to meet crop requirements in a timely manner, reduced application of nitrogen fertilizers tailored to the different stages of plant growth, using Legume plants in crop rotation, proper crop residue management, use of slow-release fertilizers, and application of nitrification and denitrification inhibitors. Methane emissions may be reduced through drainage of rice paddies to provide adequate ventilation for methane oxidation and tillage or composting to decompose crop residues before flooding.

Wheat is the main staple food in Iran where itaccounts foralmost one third of the area under crop cultivation. Being the most important sources of nutrients supplied to wheat farms, chemical fertilizers have caused environmental problems due to their excessiveapplication beyond plant requirements. One solution to resolve these problems and to achieve sustainable agriculture is biofertilizer applicationsince thesecompounds enhanceplant growth by fixing molecular nitrogen, dissolving insoluble elements such as phosphorus and zinc, releasing soil potassium, producing siderophore to increaseironavailability, oxidating sulfur, and producing growth promoting materials. Research has confirmedenhanced wheat growth and yield as a result of biofertilizer application.  Biofertilizers are also reportedly able to reduce the adverseeffects of environmental stresses such as drought and salinity on wheat by producing ACC-deaminase enzyme, osmolite compounds, and extracellular polysaccharides. Not only has biofertilizer production witnessed a dramatic rise worldwide, especially in developed countries,but Iran has also recently produced and introduced a variety of biofertilizers for various crops, including wheat. A number of guidelines and quality standards for biofertilizer productionhave also been developed in some countries such as Iran. Research has shown that seed inoculationis an effective and economical method of biofertilizer applicationand, further, thatskilled professionals, technical know-how, and infrastructure available to the private sector in Iran may be regarded as the potentials and opportunities forincreasing biofertilizer production and applicationinwheat farming. However, their use is reportedly limited by the poororganic contentofIranian soils;the heterotrophicbacteria used in their production;the chemical fertilizersabundantlyavailable on the market;the need for special equipment and preparations;and the lack of proper communication amongthe research, production, and extension sectors. Research in the field may be boosted by investigating the responses of different lands to biofertilizers for wheat production and fundamental molecular research may be carried out to achieve enhanced growth promoting properties and establisha symbiotic nitrogen fixation.Biofertilizer production and consumption may also be increased by calling in the mass media to publicize the benefits of their application. Finally, basic and molecular research isrecommended on the growth stimulant properties of microorganisms.

Natural resources comprise principal ingredients of human life and require special consideration of their potentials and realities within a comprehensive and integrated framework; such an outlook might be only achieved through a disciplined planning and management system. Resource exploitation in the absence of due attention to sustainability principles will lead to irreparable or costly effects. Using the land use map of 2014, the present study employed GIS to estimate soil displacement due to tillage operations in an attempt to develop planning schemes, making managerial decisions, and implementing projects to reduce soil displacement rates across the dry farms in Chehelgazi sub-basin. For this purpose, the land use and sloping maps of the dry farms in the region were prepared and the type of tillage tools (plow and chisel) used were identified using the exiting data and field visits. Subsequently, soil displacement equations were developed according to the type of tools used and soil displacement estimates in the region were obtained. The results showed the high potential of tillage erosion and soil displacement due to the large area under dryland farming in this sub-basin so that the average longitudinal soil displacement due to reversible plough operation as the dominant practice in the basin was estimated to range from 1.40 to 44.53 m. The importance of tillage operations and soil erosion as well as the role of the sub-basin in supplying water to Gheshlagh dam require more decisive actions to reduce soil movement and to monitor and improve the agricultural system in Kurdistan Province and across the whole state.

Remote sensing is the key technology used to assess land use changes that serve as basic information in all planning. The current study uses the Markov chain model to investigate changes in the area under pistachio cultivation and explores its potential for predicting future variations in land use in Zeidabad, Sirjan. For this purpose, use is made of ETM+ Landsat 7 and OLI Landsat 8 sensor images taken in the years 2000, 2010, and 2019, all of which are classified into the two land use classes of vegetation (pistachio plantations) and non-vegetation (residential areas, riverbeds, barren land, and pastures). The results obtained indicate an upward trend in agricultural development, particularly in pistachio cultivation as the most dynamic land use, in the study region so that an increase of 1888.83 hectares (15.04%) is recorded for the total cultivated land. Similarly, an upward trend is recorded for changes in pistachio plantations during the years 2010 to 2019 so that 1685.07 hectares (11.66%) of land is shown to be added to the total land area under pistachio cultivation. Markov chain analysis of the period from 2010 to 2019 indicates a steady increase in pistachio cultivation in the study region by 2029.

Proper siting of rainwater conservation systems is an important step to ensure water supply in a watershed. The present study was carried out to identify the factors involved in rainwater infiltration and storage and to determine suitable locations for the construction of rainwater conservation systems in Nazluchai Basin, Urmia. For this purpose, slope, rainfall, land use, soil texture, and soil depth were selected as the parameters affecting rainwater storage and subsequently subjected to AHP analysis in order to determine the weight of each in the different improvement operations studied. In a second step, the TOPSIS model was used to prioritize the sub-basins with regard to the improvement operations of pitting, contour trenching, terracing, and contour furrowing. Based on the results, pitting was found superior to the other improvement operations in the study area as evidenced by the Ci values of 0.94, 0.28, 0.20, 0.31, 0.08, 0.02, and 0.01% obtained from the TOPSIS model for pitting in sub-basins 1 to 7, respectively, indicating the higher priority of sub-basin 1 for performing the pitting improvement operation. According to the same results, sub-basins 3, 2, and 4 were identified as the priority ones for contour trenching, terracing, and contour furrowing, respectively. It was found that while the costly rainwater harvesting schemes cannot be economically justified for the study area, the alternative rainwater conservation schemes may be of priority on economic grounds.  A final finding of the study indicated that not only the criteria but also the combined AHP-TOPSIS model used in this study may help state executive departments to select appropriate improvement operations in other watersheds.

On the eve of the Constitutional Revolution when the parliament was first established in Iran (1906), a large amount of governmental property, then termed as ‘Net Property’, was exploited through a kind of lease agreement to landlords and users in return for revenues under a feudal system. One of the most important bills passed by the first parliament was the Act on Abolition of Feudal Ownership of Public Property. The present library survey reviews the proceedings from the parliamentary discussions leading to the above-mentioned Act. It was found that efforts to raise the government’s income through reducing pays to the lessees of public property and to increase the revenues from the returned property on lease had been the most important motivation behind the Act. It was also observed that, although landlords were members on one of the six parliamentary committees at that time, no serious objection had been raised and that the act had been adopted unanimously after only five parliamentary hearings. The documents reviewed also revealed that at least 15 percent of the PMs had actively participated in drafting the Act. It was concluded the MPs’ main drive in passing the Bill had been escalation of government financial resources.

Fallout radionuclides, FRNs, (i.e., 137Cs, 210Pbex, and 7Be) are being increasingly used to obtain quantitative information on soil erosion and sediment redistribution within agricultural landscapes over different timescales. The technique is frequently regarded as a valuable complement to conventional measurement methods. The objective of the present article is two-fold: to review the advantages and limitations of each of the above three FRNs and to identify the key gaps in the current knowledge on their application. In addition, guidelines are introduced for selecting the most appropriate FRNs and the associated application methods for a wide range of spatial and temporal scales. Also, the key objectives to be pursued in future investigations including upscaling FRN applications in soil erosion to catchment scale and the shift from their use as a research tool to a decision support one will be explored.

As natural land features, landscapes ranging in size from large plains and mountains to small hills are regarded as morphological formations characteristic of the earth's surface. The objective of the present study was to determine the physiographic unit boundaries in Hormozabad, Rafsanjan, using the ordinary kriging estimator. For this purpose, 77 observation points at distances of 500 m from each other were selected over a regular sampling grid and soil samples were collected from depths of 0–40, 40–80, and 80–120 cm at the specified locations. Similar to the findings reported elsewhere and based on model efficiency estimates, the results obtained showed that ordinary kriging served as a good estimator in zoning the properties of the study area. Additionally, geostatistical results indicated that a sampling distance of 1800 m could be used as a criterion for future surveys in areas similar to the present study one. Comparison of the kriging and topographic maps of the area demonstrated that the kriging estimator used was superior to topographic maps in representing physiographic units. This was evidenced by the more accurate unit boundaries detected by the estimator despite the high variations in soil properties depicted in the respective variograms for intervals above 1800 meters. It is, therefore, recommended that modern techniques such as geostatistics should be employed for detailed soil studies as required for preparing more adequately detained maps with precise data.