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Soil compaction is one of the worst signs of soil physical collapse, which has multiple effects on reducing its physical quality. On the other hand, parameters such as aggregate stability, bulk density, hydraulic conductivity and porosity, which are the most important indicators of soil physical quality, are usually more vulnerable to improper management due to the environmental conditions of arid and semi-arid areas. In recent decades, due to not being in tune with new technology, farmers have turned to more use of machines and agricultural chemicals in order to increase production.  One of the consequences of improper land management is the compaction of the bottom layer of the plowing depth, which can be seen in almost every part of the land in Kermanshah province in recent years. This study was done as a first step in investigating this problem.

Sanjaabi plain of Kermanshah with an area of about 67,000 hectares was considered as the study area. The number of 102 points was determined by a simple systematic method. Disturbed samples were taken from the two surface layers and the bottom of the plow, as well as undisturbed samples were taken by metal cylinders from the depth of the plow pan. After Laboratory analyses, the aggregate stability was checked in both dry and wet conditions. Statistical analysis was determined using SPSS statistical software. The correlation coefficient was obtained by the Pearson method along with the correlation test. Cumulative quality indices (IQI) and Nemoro quality indices (NQI) were obtained in two collections of total data (TDS) and minimum data (MDS) through the method of principal component analysis (PCA). Then, variography and zoning of soil quality indicators were done for the spatial evaluation of soil quality using kriging method.

In the surface layer and bottom of the plow, 10 and 8 principal components were able to estimate 85.02 and 80.18 percent of the total variance, respectively. The IQI correlation coefficient of the total data set with the minimum data set in the surface layer and bottom of the plow were 0.76 and 0.61, respectively, and the Nemoro index was 0.72 and 0.58 respectively. A spherical model was fitted to all the soil quality indicators in two minimum and total data sets in two surface layers of the soil and the bottom of the plow and showed a strong spatial correlation. The parts from the north to the northwest as well as the northeast of the region had higher quality soil. Other parts of the region have low to medium quality soil due to heavy tillage, reduction of organic matter, reduction of stability of aggregate and then increase of bulk density and soil compaction.

In general, the nature of the soil, due to the decisive effect of the parent materials, has caused a uniform type, which was evident in the texture, calcareousness and mineralogy of the clay part. Continuous and intensive agricultural operations have fueled this uniformity. In the areas with high amounts of clay in the surface layer of the soil, due to the flocculating of clay and organic matter and the subsequent increase in the aggregate stability, the quality of the soil was more suitable. But in the bottom of the plow, continuous cultivation in the region has caused the soil to become even more dense due to the low amounts of organic carbon and high amounts of clay. The results of the correlation studies showed that MDS can be used with acceptable reliability instead of TDS in the soil quality assessment in the two layers of the surface and bottom of the plow. This confidence was less in the plowing bottom, which is probably due to the excessive destruction of the soil structure as a result of its compaction and homogenization.

One of the ways to reduce evaporation from the soil is to use modifiers. The aim of this research was to evaluate the effect of modifiers with two mixed and surface applications on the rate of evaporation from the soil. This research was carried out in the greenhouse of the Faculty of Agriculture of Lorestan University with treatments of wheat straw and cow manure at three levels (zero, 1 and 5% weight). The soil moisture was kept constant for 4 months at the agricultural capacity. The amount of evaporation in June and August 2021 in each pot was measured by weight in two periodes of 10 and 18 days. The results showed that there was a significant difference in the rate of evaporation between the treatments used with surface application and mixture. After the end of evaporation measurement and stopping it in June and August, wheat straw had the lowest evaporation. The use of wheat straw at the level of 5% by weight on the surface in June 4.7 and in August 1.7 times compared to the control treatment had the greatest reduction in evaporation. In addition, the use of modifiers improves the soil structure, which the results of this test show with the highest MWD with the use of a mixture of 5% by weight of wheat straw in the amount of 0.48 mm. Due to the significant difference in the application of modifiers, the surface application of modifiers is recommended to control the rate of evaporation.

Although the use of fertilizer in poor soils is essential for increasing soil fertility and optimal growth of plant, but in recent years, chemical fertilizers have caused a lot of environmental damages. Thus, this study was conducted to investigate the effect of organic matter (Rice Husk) and mineral modifiers (Clinoptilolite Zeolite) on some soil properties. For this purpose, an experiment was performed in 2020 in the greenhouse faculty of the agricultural and natural resources of lorestan university. Test treatments include: 1- organic modifiers with three level (1, 3, 5 wool weight) and mineral modifiers with three level (3, 5, 10 wool weight) and control treatment 2- three different incubation time (30 as control, 60, 90 days). Before starting the proposed times, one month incubation was applied to the soil to adjust the soil material. The result showed that the use of both modifiers increased average weight of the aggregate diameter, porosity, weight moisture, electrical conductivity, total nitrogen, acidity, carbon ratio to nitrogen and microbial respiration compared to the control. The average weight of aggregate diameter increased by 26.7% compared to the control. But, the amount of bulk density and the hydrophobicity of the samples were decreased as compared to the control treatment. 10% weight of zeolite and 3% weight of rice shell treatment reduced hydrophobicity by about 37.8% compared to the control. Over time, the amount of bulk density, porosity, electrical conductivity, organic carbon, total nitrogen and microbial respiration showed a reduction trend, but the soil acidity and carbon ratio to nitrogen had an increasing trend. The carbon/nitrogen ratio during the incubation period of 60 and 90 days, significantly increased by 7.04 and 17.32% compared to the control. The result of data analysis showed that the effect of time on hydrophobic and average weight of the aggregate diameter and weight moisture was not significant.

The main challenge facing the agriculture sector is producing more food while using less water so it is needed to increase water use efficiency and optimal use of water resources, especially in arid areas. The main goal of this research is to study the effect of irrigation with municipal wastewater effluent and water use efficiency of maize in farms located in south- west of Shahr-e-kord. All of treatments were used in randomized complete block design with split plots and three applications with five factors including 100% well water (M1), 25% wastewater 75% well water (M2), 50% wastewater 50% well water (M3), 75% wastewater 25% well water and 100 % wastewater (M5) and four sub treatment factors according to the different amounts of water, wastewater and mixture of water and wastewater on the basis of water requirements (50% (L1), 65% (L2), 85% (L3) and 100% (L4)). In the different treatment types of water, M4 (25%well water and 75% wastewater) had dry matter yield. Regarding to total dry matter, the yield of biomass, grain and water use efficiency were more in M4 treatment and the less water use efficiency was determined in 100% wastewater treatment (M5). In different amounts of water treatments on the basis of total dry matter, the most total dry matter yield, biomass, grain and water use efficiency were determined in 100% crop water requirement treatment (L4). On the basis of biomass yield, 85% crop water requirement treatment (L3) had more water use efficiency. The results show that for total dry matter, biomass and grain yield 75% wastewater 25% well water was the best treatment in irrigation of considered area. On the other hand, wastewater contains nutrients and can be used without fertilizer consumption in this area, so it is useful in saving water and fertilizer.