The assessment of soil suitability for sustainable intensive agriculture is important for the selection of land suitable for agricultural production with the least economic and environmental costs. This study was directed to evaluate agricultural soil suitability in the south of Hail province, Saudi Arabia to suggest alternative crops of alfalfa using the Agricultural Land Evaluation System for arid regions (ALES-Arid) model and Geographic Information System (GIS). The study area covers about 77558 ha and 111 soil samples were collected from 37 profiles and 37 groundwater samples were analyzed for physical, chemical and fertility properties. To evaluate land suitability for selected crops, the FAO guideline was used and also to analyze and map soils within the study area, the GIS was employed. The main research goals were to characterize the soil and water resources of the study area, in order to plan the best alternative crops of alfalfa using land evaluation facilities for different purposes (capability and suitability). The results indicated that the soils of the area are characterized by sandy loam texture, low fertility, low total carbonate and most of the area have moderate to high salinity soil. Capability classes of the area are C3 and C4 which covers about 89.19% and 10.81% of the total area, respectively. The most fertile classes were situated in C2 and C3 which covers 37.84 and 40.54% of the area with phosphorus and potassium limitation. The land suitability results show that 99.68, 97.18 and 85.37% of the area is classified as S1 (highly suitable) for wheat, barley and alfalfa, respectively; while 98.91% of the area is classified as S3 (marginally suitable) for maize. From the obtained data, growers are advised to cultivate barley or wheat in winter and maize in summer instead of alfalfa, in order to save irrigation water. This is also because the expected productivity of either wheat or barley is high. It is important for decision makers to determine the best way of using land for agricultural purposes, since it serves as a decision and planning support.

The wide use of mulch by the agricultural system in most parts of the world and with multiple applications, is necessary to improve our knowledge of the effects of mulching on soil physical properties. Thus, this review a critically explains the mechanism of this application. Generally, it affects a field's energy balance by changing the surface radiation budget, by modifying the albedo of the soil surface or shading the soil surface. This has an effect on net radiation. The effect of mulching on evaporation is that it breaks up capillary diffusion and this depends on the type of mulch. Mulching also affects soil water content and soil temperature, the extent to which depends on the type and thickness of the mulch, the soil texture type and climatic conditions. Several studies have reported that the influence of mulching on greenhouse gas emissions is unclear.

As a result of the arid climate of Saudi Arabia, groundwater is the most precious natural resource, providing reliable water supply for the resident population and the development of irrigated agriculture where surface water resources are insufficient and little to meet the water budget requirements of the Kingdom of Saudi Arabia. Therefore, this study was carried out to evaluate the quality of groundwater resources in selected locations of Hail region. This study focused on the important chemical analysis of the available groundwater resources in Hail region. Groundwater samples were collected from 61wells at different locations that cover the Hail region for chemical analysis. Parameters such as pH, electrical conductivity (EC), sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), carbonate (CO3--) bicarbonate (HCO-3), chloride (Cl-), and heavy metals were analyzed moreover the calculation of sodium adsorption ratio (SAR) to assess the suitability of groundwater for agricultural purposes. The pH values were between 7.10 and 8.23 (M = 7.66). The salinity of groundwater, as a primary indicator of water quality for irrigation, ranged between moderate and high (between 0.27 to 8.99 dS m-1) in most studied water samples. Besides salinity, 31.1% of Hail groundwater samples have the potential risk of chloride hazard (chloride > 10 meq L-1). SAR values were less than 9 for all groundwater samples while the heavy metals were within acceptable levels.