javad givi

Introduction: Wheat is one of the key cereals that provides a nutrition source to millions of people around the world. By conducting applied studies, the limitations of soil and climate that reduce the yield per unit area must be understood and solutions should be provided to address these limitations. One of these strategies is a detailed study and spatial prediction of yield at points with different soil and climate characteristics. Models that predict crop yield can estimate the yield regarding climate, landscape, soil and management constraints. Considering the arid and semi-arid climate of Iran, the shortage of yield per unit area and the growing population, the country needs new research and strategies to increase yield per unit area. For this purpose, the first step is to examine the spatial variations of the yield. In the present study, the factors affecting the rainfed wheat yield in order of importance and efficiency of different methods of estimating spatial variations were investigated and the predicted yield of this crop was mapped digitally. Materials and Methods: The study area, with an area of 6700 hectares is located in Badr watershed, around Ghorveh city, Kurdistan province, west of Iran. The mean annual air temperature is 12.1oC and the average annual precipitation is 345.8 mm. The soils of the area were classified in the orders of Entisols, Inceptisols and Mollisols and in 32 soil families, according to the last version of Keys to Soil Taxonomy. Based on hypercube technique, 125 observation points were selected, soil profiles were dug and described at these points and soil samples were collected from horizons of the profiles. Some physical and chemical characteristics of the soils were determined according to the standard laboratory methods. Rainfed wheat yield was measured at each side of one soil profile in a 1m×1m quadrangle. In the present study, in addition to geomorphological data, different types of auxiliary variables such as some of the primary and secondary derivatives of digital elevation model (DEM) and Landsat satellite image data were used. To find out the affecting auxiliary topographic and plantcover data on rainfed wheat yield prediction in order of importance,ReliefAttributeEval algorithm of WEKA software was used. Artificial neural network, decision tree Analysis, discriminant analysis, and averaging k-nearest neighbors are the models that were used in this research for prediction of rainfed wheat yield. Results and Discussion: Calcium carbonate, organic carbon and coarse fragments, respectively with variability coefficients of 174.4, 62.4 and 61.3%, had the highest variation and pH, CEC and sand, respectively with 3.6, 16.9 and 20.3% variability coefficients showed the least variability in the soils of the studied area. In addition to geomorphological data, the parameters that were taken from the digital elevation model include elevation, slope percentage, slope aspect, slope curvature, slope surface curvature, longitudinal curvature, slope relative position, wetness index, multiresolution valley bottom flatness index, multiresolution ridge top flatness index, valley depth, channel network base level, modified catchment area, catchment slope, catchment slope aspect and catchment height. The environmental parameters that were taken from the Landsat 8 satellite imagery, include the normalized differential vegetation and the soil-adjusted vegetation indices. The ReliefAttributeEval algorithm in Weka software, in order of decreasing importance, identified geomorphology, relative slope position, longitudinal curvature, multi-resolution ridge top flatness index, slope, normalized differential vegetation index and soil-adjusted vegetation index as the most important factors affecting rainfed wheat production in the studied area. The amount of rainfed wheat yield was predicted by the models of artificial neural network, decision tree analysis, discriminant analysis, and averaging k-nearest neighbors. The error criteria for this prediction and a significant correlation between measured and estimated values of the rainfed wheat yield, indicate a higher accuracy for the averaging k-nearest neighbors model, compared to other models. The spatial distribution of the rainfed wheat yield, predicted by the averaging k-nearest neighbors model, was mapped. In the Badr watershed, the yields are continuously reduced towards the mountains. In this landscape, as the slope increases, depth and water storage capacity of the soil decrease mainly in the presence of Entisols. These soils are seen in the eastern, southern and western parts of the watershed. At lower elevations, the soils are deeper and are mainly Inceptisols. Rainfed wheat yield increases in the piedmont landscape, including hill, glacie and alluvial fan. Conclusion: In order of decreasing importance, geomorphology, relative slope position, longitudinal curvature, multi-resolution ridge top flatness index, slope, normalized differential vegetation index and soil-adjusted vegetation index are the most important factors affecting rainfed wheat production in the studied area. The averaging k-nearest neighbors model has a higher accuracy for rainfed wheat yield prediction, compared to other models. In the Badr watershed, the rainfed wheat yield is continuously reduced towards the mountains in the eastern, southern and western parts, where mainly Entisols are present. The yield increases in the Inceptisols, located on the piedmont landscape.

In the assessment of land suitability, the land-production capacity is identified and the type of use is determined in proportion to that capacity. In this regard, the FAO approach has been used by many scholars in different parts of the world and Iran in land suitability assessment studies. In this approach, the most commonly used method is the parametric method. The FAO approach uses Boolean logic to assess land suitability. This logic has been criticized by a number of land evaluation researchers. Because it does not take into account the continuous nature of the soil variations along the earth's surface and the uncertainty in the measurements. To overcome these shortcomings, the fuzzy analytical hierarchy process (FAHP) was presented to determine the land suitability classes. Land suitability should be determined based on a fuzzy analytical hierarchy process, in which, unlike the FAO method, unequal importance for different land characteristics and continuity of soil variations are considered. This research was carried out with the aim of qualitative land suitability evaluation in Dashtestan area, Bushehr province for Kabkab date palm (Phoenix dactylifera L. cv Kabkab) plantation, using two methods of FAO parametric (second root formula) and fuzzy analytical hierarchy process (FAHP) and comparing these two methods. The study area is located in Dashtestan region, Bushehr province, Iran; between latitudes 29º 12΄ and 29º 31΄ N and longitudes 51º 09΄ and 51º 59΄ E. Its surface area is 23000 ha. The mean annual rainfall in the area is 250 mm and its mean annual temperature is 27 °C. The soil temperature and moisture regimes are hyperthermic and ustic, respectively. The physiographic unit which is river alluvial plain is very gently sloping. 80 % of the Kabkab date palm plantation is present in the study area. In order to achieve the objectives of this research, 50 date palm groves, each with an area of at least 0.5 ha and a palm of Kababab cultivar, aged 20 to 25 years, with the same management level and having different soil, were selected as observation points. Then a soil profile was dug randomely in each date palm grove, with dimensions of 1.5 (length), 1 (width) and 1.5 (depth) meters and described, using soil profile description guide. Soils were sampled from different horizons of the profiles and the required physical and chemical analyses were carried out on the samples, according to the standard laboratory methods. The drilling site was chosen to have a date palm tree in each of the four corners of the profile. The yield of the four trees located in four corners of each profile was measured and their average yield was considered as the final yield for the corresponding profile. Meteorological data was collected for a 10 year period from the nearest synoptic station (Borazjan station, Borazjan, Bushehr). Land indices were calculated, using soil and climatic data and parametric (second root formula) and fuzzy AHP methods. Weighted average of the climatic and the soil data was used and finally a land index was calculated for each soil profile. In the fuzzy AHP method, relative weight of each of the studied criteria was determined by analytical hierarchy analysis with establishment of pair wise matrix. Degree of membership for each soil and climatic criteria was also determined through membership functions and finally, land suitability classes were determined. At the end, accuracy of the methods was also compared. Landscape characteristics such as slope, drainage and soil depth were not considered in the land evaluation, because these characteristics did not show any limitation for the date production in the study area. The results of qualitative land suitability evaluation based on fuzzy AHP method showed that 96.6 and 3.4 percent of the studied area are classified as S2 and S3, respectively. This is in the case that based on parametric (second root formula) method, 82 and 18 percent of the studied area are marginally suitable and non-suitable, respectively. According to these results, higher land suitability classes were obtained, based on fuzzy AHP than through parametric method. Correlation between the calculated land index and the measured yield, determined for the fuzzy AHP method was higher than the one obtained for the parametric method. This proves that the fuzzy AHP is a more appropriate method for land suitability assessment for Kabkab date palm plantation in the studied area than the parametric method (second root formula). According to the results of this research, the fuzzy AHP is a more appropriate method for qualitative land suitability evaluation than the parametric method (second root formula) for Kabkab date palm plantation in the studied area in Bushehr province.

The optimum and sustainable use of soil is possible only with correct and complete understanding of its properties. The objectives of the this study were to enhance understanding of soils available in an area located on 35 km of Chelgerd region in Chaharmahal –va- Bakhtiari province through the study of the Soil morphological, physico-chemical, mineralogical and micromorphological characteristics to check the formation and classification of these soils according to USDA Soil Taxonomy (2014) and WRB (2014) systems.
Mean annual rainfall and soil temperature of the selected location are 1389.6 mm and 9.5 ℃ respectively and Soil temperature and moisture regimes of this region are mesic and xeric, respectively. Eight pedons located on one transect along slope direction were excavated and sampled. Routine physico-chemical analysis such as soil reaction, texture, COLE content, electrical conductivity, calcium carbonate equivalent, cation exchange capacity, organic carbon and clay mineralogy and micromorphology investigations were performed on selected soil samples. Then, based on description card of each profile and laboratory results, soils were classified to phamily level and to second level based on Taxonomy and WRB systems, respectively.
the results showed that the category of the soils of the area according Taxonomy system, are Inceptisols and Vertisols, while in WRB system, named Calcisols, Cambisols and Vertisols. The results showed that, because of higher organic matter content and finer texture of soils of lower slope positions, cation exchange capacity was maximum in this position. The results also revealed that, with increasing soil depth, organic carbon content and cation exchange capacity decreased, whereas clay and lime content had a reverse trend and increased with increasing the soil depth. Coefficient of linear extensibility (COLE) values as well as clay content increased from back slope to foot slope and with increasing soil depth. They are constituted mainly by smectites associated to some amount of illite, chlorite, kaolinite, quartz and illite- smectite as mixed minerals. According to this results, the origin of the clay minerals in different slope positions are mostly inheritance from parent material. Study of thin section revealed the presence of clay coating in the Bt and Btk horizons, that, this clay coatings in the soil are evidence of transmission clay from upper horizons to lower horizons as a result of water penetration. Also, calcite accumulation with various forms such as calcite coating, calcite infilling and calcite needle and calcite nodule in the Bk and Btk were observed, which, confirms the secondary nature of lime and causing calcitic crystalitic b-fabric. Also, the cause is the accumulation of calcite needle in the top of the slope due to highlands area, presence of enough moisture in the soil, the low salinity of soil and presence of biodegradable organic matter.
the result of this study showed the role of topography on variability of soil properties and soil classification in the studied area.

Loess derived soils, in both arid and humid areas are the most common soils that are formed in eolian sediments. Lamellae as thin bands are observed in both alluvial and eolian soils in various landscapes. Each lamella separates from the other one by a band with less clay content. The lamellae play a role in increasing water and nutrient holding capacitis of the coarse textured soils. Also in archaeological and geomorphological studies, indicate the approximate age of the soils. The objective of this research has been to study the macro-morphology, micro- morphology, physical and chemical characteristics of loess- derived soils with lamella.
The study area is located twenty kilometers east of Zavareh, Ardestān city, north-east of Isfahan province. This area has an average annual rainfall of 110 mm and an average annual temperature of 19.5oC. Its parent materials are loess and its land form is piedmont plain. In the study soils, eight soil profiles were excavated, described and disturbed soil samples were collected from all of their horizons to investigate about the morphological, physical and chemical characteristics of the soils. Of the eight studied soil profiles, in two profiles, bands with different color and texture (lamella and the eluvial part) were observed. Micropedological studies including preparation and description of soil thin sections were carried out for these soil profiles. All of the studied soil profiles were classified at phase of soil series level.
The studied loess –derived soils that all of them are Aridisols were classified in three suborders, four great groups, four subgroups, five families, eight series and eight phases of series. The results showed that in some horizons of the loess-derived soils, there are lamellae that meet argillic horizon requirements. In geogenic stage of lamella formation, with decreasing wind speed, finer particles precipitate in the form of very thin horizontal bands, parallel with the bands of coarse particles. In the pedogenic stage, with stop of a wetting front at the border between the layer of fine-grained and the underlying coarse-grained layer and before saturation of the fine-grained layer, the wetting front loses its moisture through evaporation or absorption by the roots. Clay particles suspended in the wetting front, after evaporation of the front moisture, form clay film on wall of the pores or on the surface of the sand and silt grains. Over time, the film thickens and the fine pores diameter of the fine textured bands is reduced until the lamella finally is formed. Occurrence of lithologic discontinuity at a depth of 140 cm and filling the channels by pedogenic gypsum crystals accelerate pedogenic formation of the lamella. Due to weathering of the primary iron bearing minerals, present in the lamellae forming materials, iron is released from the minerals and after oxidation, precipitates on the lamellae surfaces.
When wind speed decreases, finer particles precipitate in the form of very thin horizontal bands, parallel with the bands of coarse particles. This stage of the lamella formation is geogenic.
Pedogenic stage begins when a wetting front stops at the border between the layer of fine-grained and the underlying coarse-grained layer, before saturation of the fine-grained layer and the wetting front loses its moisture through evaporation or absorption by the roots. Suspended clay particles, present in the wetting front, after evaporation of the front moisture, form clay coatings on wall of the pores or on the surface of the sand and silt grains. Over time, this coating thickens and the fine pores diameter of the fine textured bands is reduced until the lamella finally is formed.

One of the ways to identification of land production capacity and appropriate use choice with that is land evaluation performance. For this purpose must first climatic criteria and soil characteristics affecting the production to be identified. Also, considering to diversity and inequality in importance degree of criteria, ranking of them is essential. This research aim to identification, ranking of effective criteria in date production and land suitability evaluation for planting of Date palm cv Kabkob in Bousher province, using analytical hierarchy process (AHP) carried out.
At first, climatic subcriteria and soil physical and chemical characteristics affecting date production were identified by literature review and soil studies in studied area. Then, pairwise comparison matrix was made over analytical hierarchy process and the relative importance degree of these subcriteria was determined by excellent experts. In the weight calculation step, the approximation method was used to produce a relative weight of each of subcriteria. Then this subcriteria, based on their relative weight, ranked. Finally, land suitability evaluation for planting of date palm cv Kabkob in studied area of Bousher province, using AHP approach, carried out.
The result showed that the most important of climatic subcriteria affecting date palm production including to length of dry season, number of days with precipitation index > 5 mm/day in repining period, average daily temperature (°C) at vegetative cycle, flowering and repining stage, heat requirement sum during the period of flowering, fruit formation and repining period, mean RH during the vegetative cycle and fruit formation period, insulation mean (n) and number of months where the wind speed is > 5 m/s during vegetative cycle. Also the result of climatic subcriteria ranking by using AHP approach showed that, temperature mean in flowering stage and numbers of months of year with wind speed mean more than 5 m/s in vegetative cycle stage with relative weights 0.161 and 0.08 have the highest and the lowest importance degree, respectively. The result showed that the most important of soil physical and chemical characteristics affecting date palm production were identified by literature review and soil studies in studied area including to soil texture, calcium carbonate content, gypsum content, acidity, organic carbon, available potassium, soil salinity (EC) and alkalinity (SAR). Base on the result of soil subcriteria ranking, soil salinity (EC) and gypsum content with relative weights 0.27 and 0.041 have the highest and the lowest importance degree, respectively. Also the result of land suitability evaluation showed that 75 percents of studied area in Bousher Provence are very suitable and 25 percents are moderately suitable for planting of date palm cv Kabkob.
According to the results of this research, is recommended for suitable site selection for date palm planting to temperature mean in flowering stage and soil salinity, much attention and importance to be given.

Granite forming primary minerals and the clay minerals that are formed from weathering of these minerals, determine characteristics of the soils that originate from the granite. Slope characteristics through their effect on soil moisture and temperature, causing changes in soil. The weathering in the soil can be expressed with the most appropriate weathering indices. This study aimed to investigate the soil formation on granite in various aspects, situations and forms of slope, using the most appropriate indices.
Gharreh –Boltagh granitic mass is located in semi-arid west of Isfahan province. In each of the northern and southern aspects of the slope, three profiles on the backslope and three profiles on the footslope were excavated, described and soil and rock samples were taken from their horizons. Physical and chemical properties of the samples were measured. Of the eight weathering indicies, the index with the highest correlation with the ratio of pedogenic iron to total iron, the clay content and bulk density, was selected as the most appropriate index.In order to assess the degree of chemical weathering from subsoil towards topsoil and in various aspects, positions and shapes of the slopes, this index was used.
Significant correlations between the weathering indices and the ratio of pedogenic iron to total iron and bulk density and non-significant correlations between these indices and the clay content were observed. Of the indices, the index of WR was the best index to express the intensity of weathering. The elements Ca, Na, and Mg have been used as mobile elements in the formula of this index. Calcium and sodium in the plagioclase and magnesium in the biotite are present. The average value of WR for granite and for regolith, derived from the weathering of this rock were calculated as 15.8 and 10.9, respectively. On convex slopes, the average values of WR and the regolith thickness were determined as 14.8 and 31 cm, respectively. These values for the concave slopes, respectively were calculated as 13.3 and 90 cm. The average values of WR and the regolith thickness were obtained as 13.9 and 80 cm on the backslopes and as 14.3 and 32.5 cm for the footslopes, respectively. The reason for the higher average value of WR and the lower average value of regolith thickness in the footslopes is presence of a granitic rock outcrop at the northern footslope. On the southern slope, the average values of WR and the regolith thickness were calculated as 14.3 and 43.7 cm and on the northern slope, these values were determined as 14.0 and 69.2 cm, respectively.
Given that the studied area is semi-arid, the amount of rain is at a level that as a result of granite weathering, basic cations are released and leached from the soil. This is the reason why the indices which are determined by the ratio of basic cations oxides to immobile elements oxides, were selected as the most appropriate weathering indices. In addition to degree and aspect, shape of the slope also affects parent rock weathering. Since less water can penetrate the soil on convex slopes, weathering in this type of slope and in concave one was minimum and maximum, respectively. As it was expected, weathering was less on back of the southern slope, relative to its foot. Unexpectedly, on the northern slope, contrary to this phenomenon happened, because there is a rock outcrop at the footslope. At the footslope, the slope is less. As a result, more water penetrates the soil and more weathering occurs. In the southern slope, weathering was less than the northern slope.