The modeling of water movement through SOILs typically requires the functional representation of SOIL hydraulic PROPERTIES, such as the water retention curve. Among different water retention models, van Genuchten (VG) model is an appropriate one. The objectives of this study were to quantify relationships between the VG model parameters and SOIL PHYSICAL PROPERTIES and to select equations that are useful for prediction of VG model for SOIL water retention curve. Fifty four SOIL samples were used for SOIL water characteristics determination by ceramic plate extractor, SOIL particle size determination by hydrometer method, SOIL bulk density and SOIL organic matter. Multiple regressions were used to determine the relationships between m and hp (SOIL water suction at reflection point of the SOIL water retention curve) and the aforementioned SOIL PHYSICAL PROPERTIES. The results indicated that multiple regression models may be used to estimate, with acceptable accuracy, the water retention curve of VG type from SOIL sand content, bulk density and Organic matter percent. The proposed regression models were used for prediction of SOIL water retention curve for three different SOILs with an acceptable accuracy.

Introduction: Conservation agriculture (CA) is considered as a suitable technique for protecting the environment, which will lead to major benefits and sustainable production. Minimum and zero tillage are recommended as they tend to reduce the cost of crop production, retain higher quantities of SOIL water, and provide PHYSICAL protection for SOIL organic carbon (Bhattacharyya et al., 2012). CA improves SOIL PHYSICAL parameters such as water-stable aggregates, water infiltration and retention as compared to conventional agriculture (Vinod et al., 2016). Conservation agriculture can improve SOIL PHYSICAL PROPERTIES and the associated processes, particularly, SOIL aeration, SOIL structure and SOIL porosity. It can also reduce SOIL erosion, SOIL compaction and crusting, and optimize the SOIL temperature for successful crop production (Indoria et al., 2017). Therefore, this study was conducted to evaluate the effects of conservation and conventional tillage on the SOIL PROPERTIES and wheat yield. Materials and Methods: This research was performed using geostatistical method through analyzing SOIL PROPERTIES and wheat yield data. The SOIL PROPERTIES measured included: SOIL texture, EC, pH, and SOIL infiltration. SOIL infiltration were determined using double ring method. The infiltration models of Kostiakov and Philip were fitted to the measured data. Wheat yield was measured at 2 m2 interval of each sampling site. Data were analyzed using SPSS, Excel, and GS+ software. Average, variance, skewness, kurtosis and coefficient of variation (CV) of data for each property were calculated using descriptive statistics. Spatial distribution maps of PROPERTIES were drawn using the best semi-variogran model and the best interpolation method. Results and Discussion: The results showed that wheat yield with a medium CV varied from 1850 to 8150 kg/ha. The best semi-variogram model for wheat grain yield was spherical model, and the best interpolation method for it was point kriging. The wheat yield under minimum tillage system was higher than that of conventional tillage. Wheat yield and coefficients of infiltration models had a significantly correlation with SOIL PROPERTIES. The best semi-varogram model for SOIL pH, EC, sand, silt, and clay percentage, and coefficient A of Philip model was spherical, and for the coefficients a and b of Kostiakove model, and I150 was exponential and for the S coefficient was Gaussian model. The spatial structure of SOIL pH, EC, sand, silt, and clay percentage, A coefficient, I150, and b coefficient was strong, and for the a and S coefficients were moderate. The best interpolator for SOIL pH, EC, sand, silt, and clay percentage, and a coefficient was kriging method and for silt percentage, b and A coefficient, and I150 was inverse distance weighting method. The magnitude of a and S coefficient was higher in comparison to the area of conventional tillage Conclusions: Results showed that, the mean wheat yield at reduced tillage, no tillage and conventional tillage was respectively 6137, 4425, and 3589 kg/ha. Conservation tillage methods increased SOIL infiltration (6%) and decreased SOIL salinity (12%) relative to the conventional tillage. Conservation tillage slightly reduced SOIL pH as compared to the conventional tillage. Reduced tillage had a positive impact on parameters of SOIL infiltration models. There was a significant correlation between SOIL parameters, which is very important for better field management. Geostatistical models derived from the data of this research are very useful for the estimation of SOIL parameters in the similar areas. Based on the results of this study, it can be concluded that, although the studied SOIL parameters had wide spatial variability, geostatistical methods with the limited data can be used to estimate them with high accuracy. The coefficient a and the coefficient S were the highest in the area where conservation tillage was applied. These results indicate that conventional tillage has reduced the movement of water in SOIL by disturbing SOIL PHYSICAL conditions, including the destruction of the SOIL structure. Finally, the best tillage system was reduced tillage. Acknowledgments: The authors would like to acknowledge the financial support extended by the Agriculture Organization of Fars province and SOIL and Water Research Institute.

SOIL moisture characteristic curve (SMC) is a fundamental SOIL property for predicting and modeling water flow and solute transport in the unsaturated SOIL, but its direct measurement is tedious and time consuming. Therefore, various indirect methods (e. g., pedotransfer functions, PTFs) have been developed to predict SMC from easily available SOIL PROPERTIES (EASP). We develop a procedure to predict SMC from ESAP and SOIL liquid limit (LL), and plastic limit (PL). Forty three SOILs were sampled from north-west of Iran. All of SOIL samples were divided in two groups; 28 and 15 SOILs samples were used to train and evaluate of the models, respectively. The SMC, (water content at the suctions 0. 1, 0. 2, 0. 3, 0. 4, 1, 2, 3, 5, 10 and 15 bar) and LL, PL and ESAP were measured through standard methods. Multiple linear regression analysis was used to make correlation between LL, PL and ESAP data as independent variables along with SMC data as the dependent variable, using the SPSS software and the stepwise algorithm. Results showed that among all measured SOIL PROPERTIES, the clay content, bulk density, LL and PL had high correlation with the SOIL moisture content at different suction heads. Values of the coefficient of determination (89%) and root mean square error (0. 028), obtained by the statistical analysis, and indicated the validity of the models in the all of the suction heads.

In order to investigate the effect of vermicompost on PHYSICAL and chemical PROPERTIES of SOIL, an experiment was carried out in split plot based on complete randomized block design in three replications in Sari Agricultural Sciences and Natural Resources University. The PHYSICAL and chemical PROPERTIES of SOIL included bulk density, particle density, total porosity, water holding capacity, field capacity, permanent wilting point, available water capacity, pH, organic carbon and electrical conductivity in SOIL. Six levels of fertilizer treatments (T1= control, T2= chemical fertilizer, T3= 20 tons vermicompost + 1/2 T2, T4 = 20 tons / hac vermicompost + 1/2 T2, T5= 40 tons vermicompost + 1/2 T2 and T6= 40 tons / hac vermicompost) and three levels of application years, one year of fertilization (1385), two consecutive years of fertilization (1385 and 1386) and three consecutive years of fertilization (1385, 1386, 1387). The results of the study showed that the application of these treatments in SOIL were significantly effective in increasing the total porosity, water holding capacity, field capacity, permanent wilting point, available water capacity, organic carbon electrical conductivity and in decreasing the bulk density, particle density and pH compared to control. In Contrast years of consumption of fertilizer did not have any significant effect on the PHYSICAL PROPERTIES of the SOIL except for FC, PWP, AWC, pH, OC and EC. The interaction between years of consumption of fertilizers were significantly different only in particle density and field capacity.

A field experiment was conducted at Danial Agro-Industrial Research Field in Khuzestan province, to study the effects of organic matter on some SOIL PHYSICAL PROPERTIES in 1997-1998. The experiment was carried out in randomized complete block design with three treatments and three replications. Treatments were control, 20 and 40 Mg/ha bagasse that were incorporated in 30 cm depth of SOIL For determining SOIL PHYSICAL PROPERTIES, SOIL samples were taken from 0-30 cm depth of SOIL SOIL PHYSICAL PROPERTIES such as infiltration rate, hydraulic conductivity, bulk density and moisture characteristics curves were determined. Results showed that with application of organic matter, bulk density decreased while hydraulic conductivity and infiltration rate increased Water content at different pressures showed no significant differences between treatments.

Introduction: SOIL moisture regime refers to the presence or absence either of ground water or of water held at a tension of less than 1500 kPa in the SOIL or in specific horizons during periods of the year. It is the most important factor in SOIL formation, SOIL evolution and fertility affecting on crop production and management. Also, it widely is practical in SOIL classification and SOIL mapping. The SOIL moisture regime depends on the SOIL PROPERTIES, climatic and weather conditions, characteristics of natural plant formations and, in cultivated SOILs, is affected by the characteristics of crops grown, as well as the cultivation practices. Determination of SOIL moisture regime within a landscape scale requires high information and data about moisture balance of SOIL profile during some years according to SOIL Survey Manual (2010). This approach is very expensive, labor, time and cost consuming. Therefore, achievement to an alternative approach is seems essential to overcome these problems. The main hypothesis of this study was to use capability of magnetic susceptibility as a cheap and rapid technique could determine the SOIL moisture regimes. Magnetic PROPERTIES of SOILs reflect the impacts of SOIL mineral composition, particularly the quantity of ferrimagnetic minerals such as maghemite and magnetite. Magnetic susceptibility measurements can serve a variety of applications including the changes in SOIL forming processes and ecological services, understanding of lithological effects, insight of sedimentation processes and SOIL drainage.Materials and Methods: This study was conducted in an area located between 36°46َ’ 10˝ and 37° 2’ 28˝N latitudes, and 54° 29’ 31˝and 55° 12’ 47˝E longitudes in Golestan province, northern Iran. In the study region mean annual temperature varies from 12.4 to 19.4 °C. The average annual rainfall and evapotranspiration varies from 230 mm and 2335 mm in Inchebrun district (Aridic regime), to 732 mm and 846 mm in Touskstan uplands (Udic regime), respectively. this study was conducted in four SOIL moisture regimes (Aridic, Xeric, Udic and Aquic), for exploring the relationships between SOIL PROPERTIES and magnetic measures. In each regimes, 25 SOIL profiles were drug, described and SOIL samples were collected from each of SOIL horizons. SOIL samples were airdried and sieved using a 2 mm sieve. The dithionite-citrate bicarbonate (DCB) method was used to measure Fed and acid ammonium oxalate for Feo. In this study, a set of environmental magnetic parameters including magnetic susceptibility at low frequency (clf), saturation isothermal remnant magnetization (SIRM), isothermal remnant magnetization (IRM100 mT) were measured. Magnetic susceptibility (c) was measured at low frequency (0.47 kHz; clf) and high frequency (4.7 kHz; chf) using a Bartington MS2 dual frequency sensor using approximately 20 g of SOIL held in a four-dram clear plastic vial (2.3 cm diameter). Frequency dependent susceptibility (cfd) was determined by the difference between the high and low frequency measurements as a percentage of c at low frequency. IRM was measured at the field of 100 mT generated in a Molspin pulse magnetizer (IRM100mT) and at the back field of 100mT (IRM − 100mT). The IRM acquired in the maximum field of 1000 mT was measured and defined as the saturation isothermal remnant magnetization (SIRM) of the SOIL sample.Results and Discussion: The results showed that moisture regime induced significant differences for SOIL PHYSICAL and chemical PROPERTIES. Diversities in genetic SOIL horizons and SOIL development degree have been increased from Aridic to Udic SOIL moisture regime. The results also indicated that selected PROPERTIES including magnetic measures and PHYSICAL and chemical PROPERTIES were significantly different in four SOIL moisture regimes. With increasing rainfall and reducing temperature from aridic to udic SOIL moisture regime, SOIL organic matter was increased. Otherwise, in arid environment Gypsic, Calcic and Salic horizons were observed in the near of SOIL surface. Fed and Fed-Feo were the highest in udic and the lowest in udic SOIL moisture regime, respectively. Moreover, higher SOIL development because of climate effect leaded to higher amount of pedogenic ferromagnetic minerals, as well as the highest were observed in the Udic regime. Otherwise, in Aquic moisture regime, the lowest value of magnetic susceptibility was obtained because of dissolution of ferromagnetic minerals (magnetite and maghemite) under supersaturating condition. In overall, close relationships were observed between SOIL PHYSICAL and chemical PROPERTIES and magnetic measures in various SOIL moisture regimes.

Clayey SOILs are characterized by distinct PHYSICAL PROPERTIES that significantly affect agricultural productivity and SOIL management. Their fine texture, high water retention capacity, low permeability, and compact structure make them both challenging and beneficial for farming. This study examines the role of clayey SOILs in agriculture, incorporating both geological and agricultural perspectives. From a geological viewpoint, the mineral composition of clay, such as the presence of kaolinite, illite, and montmorillonite, influences how the SOIL behaves under various environmental conditions. These minerals impact water retention, nutrient availability, and the SOIL's response to tillage and compaction. In the context of agriculture, understanding these geological PROPERTIES is essential for developing effective management strategies. For instance, while clayey SOILs can retain moisture, they can also become easily waterlogged or compacted, reducing root growth and limiting oxygen availability. Therefore, agricultural practices must be tailored to improve SOIL structure, enhance water infiltration, and prevent erosion. This research highlights the importance of integrating geological knowledge with agricultural strategies to address the specific challenges of clayey SOILs. By considering both the PHYSICAL and mineralogical PROPERTIES of clayey SOILs, farmers can adopt practices that optimize crop yield, minimize SOIL degradation, and promote sustainable farming. The study suggests that a combination of SOIL amendments, crop rotation, and careful irrigation practices can enhance the productivity and environmental sustainability of clayey SOILs.

Crust formation leads to development of a dense hard layer on SOIL surface which effectively retards seed germination and water intake. Various remedies have been proposed to overcome this difficulty. The purpose of this study was to examine the effects of polyacrylamide (PAM), pumice and straw, applied as amendments, on some characteristics of SOIL crust (0-10 mm) and water infiltration into SOIL under sprinkler and surface irrigation simulated in SOIL columns at laboratory. The columns were prepared by evenly packing (Db=1.4 gr/cm3) of the SOIL (Coars- loamy, mixed (calcareous) mesic, fluventic) in PVC tubes of 15 and 25 cm long and 15 cm diameter. Pumice at the rates of %1 and %3 and wheat straw equivalent to 2.1 and 5 tons/ha were well mixed with 0-5cm layer of SOIL in each column. PAM was dissolved (50 and 100 mg/lit) in tap water of EC=0.5 ds/m and SAR=2.2. SOIL columns were watered either by a rainfall simulator or by continuous flooding of SOIL surface by application of a 2 cm head of water. Infiltration was measured during the experiment until steady state intake was realized, then the SOIL surface allowed to eventually dry and to crust. Bulk densities (Db) of 0-10 mm layer and penetration resistance were measured by clod and cone penetrometer, respectively. All amendments, irrespective of application rates, significantly (P<0.01) reduced Db of 0-10mm surface layer and increased its porosity. Db's averaged over amendment type and application rates were 1.36, 1.67 for sprinkling and flooding as compared to 1.82 for untreated SOIL, implying that amendments acted more effectively in reducing surface densification under sprinkling rather than flooding. Penetration resistance (Pr), measured 2, 4 and 6 days after irrigation behaved similar to Db. Pumice %1 resulted in lowest resistance of 3.25 kPa as compared to 4.51 kPa in untreated SOIL, which indicates a significant differences at %1 level.Regarding water retention behavior, only pumice %3 significantly increased moisture content at 10 kPa suctions as compared to untreated SOIL (0.22 versus 0.19 g/g, respectivity).

SOIL compaction has adverse effects on SOIL PHYSICAL PROPERTIES and hence on crop yield. It hinders crop root development, increases SOIL resistance and bulk density, decreases pore size and volume and finally infiltration of water into SOIL. In order to study the effects of subSOILing on SOIL PHYSICAL PROPERTIES and wheat yield, an experiment consisting of 5 treatments was conducted. The detail of each treatment was as follows: (1) S1P1, subSOILing to a depth of30-35 Cm plus moldboard ploughing, (2) S2P1 subSOILing to a depth of 40-45 Cm plus moldboard ploughing, (3) S1P0 only subSOILing to a depth of 30-35 Cm, (4) S2P0 subSOILing to a depth of 40-45 Cm, and (5) S0P1 only moldboard ploughing (Control). Before conducting the experiment, bulk density, cone index and intake rate were measured. These measurements were replicated after the first irrigation in each plot. SOIL layering, texture, and Organic Carbon were determined in the experimental site. Finally, the wheat yield from each plot was measured. The results showed that subSOILing caused reduction in the bulk density and SOIL cone index and increased the basic intake rate and wheat yield. The best treatment in this study, in view of decreasing SOIL compaction was S1P1 which caused decreased the cone index, bulk density 12.8 and 4.1, respectively and increased the wheat yield up to 3.8. The S1P1 treatment caused and increase in basic intake rate up to 2.4 relative to basic intake rate prior to irrigation.