Ayman A. Suleiman

University of Jordan | UJ · Department of Land, Water, and Environment

The threat of land degradation by salinization in Jordan has been increasing over the last decades. Therefore, information about the response of local cultivars to salinity is needed to help farmers choose the most productive cultivars for areas with salt-affected soils. A recently released durum wheat cultivar Um Qais (Triticum turgidum subsp. dur...

The increasing competition for water has led to the need for a better water resources management, especially for crops irrigation. A water balance tool in crop models is useful for the determination of the best agricultural water management practices that maximize the crop yield and the water productivity while avoiding the need for costly field ex...

The Analytical Land Atmosphere Radiometer Model (ALARM) has been tested in several countries with observed evapotranspiration (ET) obtained from different ground-based methods, but none from a lysimeter, which is considered the most accurate ground-based method of measuring ET. The first objective of this work was to test ALARM against lysimeter ET...

This study compares saturated hydraulic conductivities (Ks) of three sandy soils such as coarse, medium and fine sand. The Ks was obtained using three different methods: empirical methods based on the grain size analysis, the relative effective porosity model (REPM), and breakthrough curve analyses based on tracer tests. Column drainage tests were...

This study investigates the performance of empirical and semi-empirical models to predict soil moisture from the data of RADARSAT II synthetic aperture radar (SAR) for the Yarmouk basin in Jordan. Data of SAR were obtained for May and June 2010 and were processed to obtain backscatter (σo) data for the study area. Results showed significant correla...

Modeling soil water evaporation and soil moisture are valuable for many applications in diverse disciplines. Ritchie and Snyder, presented different models to estimate soil water evaporation (ES) rate. The former also simulates the soil water dynamics at different soil depths. The objectives of this study were to evaluate the potential use of the S...

This study investigates the impact of climate change and land use change on water resources and food security in Jordan. The country is dominated by arid climate with limited arable land and water resources, where the per capita share of water is less than 145 m3/year. The study focused on crop production and water resources under trends of anticip...

Spectral reflectance for soils and vegetation of the Yarmouk basin were correlated with surficial soil properties and vegetation biomass and cover. The overall aim of the study was to identify bands suitable for assessing soil and vegetation as indices for land degradation and desertification. Results showed that vegetation was well separated from...

A computer simulation model can be used as a tool to help explain the impact of drought stress on plant growth and development because it integrates the complex soil–plant-atmosphere system through a set of mathematical equations. The objectives of this study were to determine the impact of different irrigation scheduling regimes on peanut growth a...

Rainfed agriculture in Jordan is one of the most vulnerable sectors to climate change, as the available water and land resources are limited and most of the country’s land is arid. In this study, a crop simulation model (DSSAT) was used to assess the impact of different climate change scenarios on rainfed wheat and barley in the Yarmouk basin in Jo...

Accurate estimates of peanut (Arachis hypogaea L.) water requirements are needed for water conservation. The objective of this study was to evaluate the FAO-56 crop coefficients for peanut grown under various levels of water stress in a humid climate. Two experiments were conducted in three automated rainout shelters located at the University of Ge...

In countries with limited water resources like Jordan; deficit irrigation (DI) could be used as a strategy to manage water more efficiently without significant yield reduction. This research was conducted in the Jordan Valley to assess the impact of two DI levels on lemon water requirements and productivity. The study was conducted for three consec...

Many applications in diverse disciplines require estimates of evapotranspiration (ET) at hourly or smaller time steps. The primary objectives of this study were to compare the American Society of Civil Engineers (ASCE) and FAO-56 Penman–Monteith equations for 15-min ET0 (ET0,15-min,ASCE and ET0,15-min,FAO) estimations for humid climate conditions a...

Most crop, hydrology, and water quality models require the simulation of evaporation from the soil surface. A model developed by J.T Ritchie in 1972 provides useful algorithms for estimating soil evaporation, but it does not calculate the soil water redistribution resulting from evaporation. A physically-based model using diffusion theory, describe...

Estimating crop evapotranspiration (ETc) is essential for effective agricultural water management and water resources planning. The objective of this study was to compare two methods for estimating daily crop ET (ETc). The first method used the Analytical Land Atmosphere Radiometer Model (ALARM) and the dimensionless temperature (DT) (ALARM-D) proc...

An estimate of evapotranspiration (ET) is needed for many applications in diverse disciplines such as agriculture, hydrology, and meteorology. The objective of this study was to compare two methods for estimating daily actual ET (ETa) from six sites located in four different ecological zones within Jordan. The first method used the analytical land-...

Crop management models require simulation of daily soil water dynamics. The objective of this study was to develop a model to simulate the daily soil water dynamics during vertical drainage with reasonable accuracy using the incoming flow concept. The execution of this model, which has been developed based on the conservation of mass law, consists...

Crop simulation models are essential tools to design management practices to mitigate such adverse conditions. They can be used to predict crop yield expectancies under limited environmental resources and various management scenarios. However, the application of crop models requires an accurate knowledge of the genotype-related coefficients, which...

Most of containerized nursery crops are grown in soilless substrates. Pine bark based container substrates, common in the southeastern USA, are characterized by a rapid variation on media moisture and temperature. The objectives of this study were to characterize the seasonal variation of containerized crops' media temperature and moisture in three...

Estimation of evapotranspiration (ET) is needed for many applications in diverse disciplines such as agriculture, hydrology and meteorology. The objective of this study was to compare two methods for estimating ET in a semiarid environment. The first method used ALARM and the dimensionless temperature procedure, while the second method used the ASC...

The climate in Georgia and other southeastern states of the United States is considered to be humid and the annual precipitation is usually greater than the annual potential evapotranspiration (ET). However, during several months of the year, supplemental irrigation is needed to prevent yield reducing water stress due to the temporal rainfall varia...

The use of the FAO-56 reference evapotranspiration (ETo) approach for irrigation scheduling has been recommended worldwide because it provides reasonable results under a wide range of climatic conditions. The crop ET (ETc) can be obtained from ETo using a stage-dependent crop coefficient (Kc). The latter depends on canopy height and crop–soil surfa...

Soil and weather conditions are not always favorable for optimal growth and development of plants and experiments must be repeated over time and space in order to obtain results that can reflect the average conditions of a specific area. Crop models and Decision Support Systems are useful tools as a complement to research, such as their ability to...

There is a lack of information about crop coefficients to be used with the FAO-56 reference evapotranspiration (ETo) approach for peanut grown in humid climates in general and under deficit irrigation in particular. The objective of this study was to determine the crop coefficients for peanut under different deficit drip irrigation treatments for a...

Lateral movement of soil solution could be a major cause for the spatial variability of crop yield within sloping landscapes. This study was an effort to develop a functional lateral downslope drainage model (LDDM) by expanding the Suleiman and Ritchie (2004) vertical drainage model. Within LDDM, the daily change of soil water content from a soil l...

The dependence of radiometric surface temperature (\(\theta\) s) on view angle and the unclear definition of the aerodynamic temperature, which is the temperature that gives the correct sensible heat flux estimate at a specified roughness length, bring about a challenge in estimating sensible heat flux from \(\theta\) s. An analytical-land-atmosphe...

Determination of evapotranspiration ( E ) is needed for many applications in agriculture, hydrology, and meteorology. The spatial variability of leaf area index (LAI) and soil water availability makes it impractical to model E over heterogeneous lands using ground‐based techniques. Remote sensing can be a good source for both LAI and radiometric su...

Accurate modeling of soil water dynamics during vertical drainage is needed for reasonable prediction of crop yield and agrochemical leaching. This study was carried out to improve the soil water drainage model in the DSSAT (Decision Support System for Agrotechnology Transfer) family of crop models. In the existing model, the daily change in soil w...

The response of NDVI to rainfall was analyzed using NOAA/AVHRR satellite imagery acquired over a time period of ten growing seasons (1981 to 1992) and rainfall data from 16 weather stations in four ecological zones in Jordan. Results of linear regression analysis showed better response of NDVI to cumulative rainfall than to 10-day rainfall with bes...

Determination of evapotranspiration (E) is needed for many applications in agriculture, hydrology, and meteorology. The spatial variability of leaf area index (LAI) and soil water availability makes it impractical to model E over heterogeneous lands using ground-based techniques. Remote sensing can be a good source for both LAI and radiometric surf...

Calculating the dynamics of soil water content (θ) near the surface and modeling soil water evaporation (Es) are critical for many agricultural management strategies. This study was performed to develop a model to simulate soil water redistribution during second-stage evaporation (SSE). In this model, the daily change of θ was estimated from the di...

The change of soil water content (SWC) during vertical drainage may be divided into two parts. The maximum change of SWC, which results when there is no incoming flow, can be predicted from hydraulic conductivity. The actual change of SWC can be predicted from hydraulic conductivity and the incoming flow. A new model has been developed to simulate...

Directional radiometric surface temperature (θr), obtained from remote sensing, can be useful in estimating the energy fluxes from the land surface, especially the sensible heat flux into the atmosphere, H. Since plant canopies are often anisothermal, θr is view-angle dependent, such that the “surface” temperature needed to estimate H may be differ...

A land surface-atmosphere-radiometer model was applied to field data at the First International Satellite-Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE). The model converts from radiometric surface temperature taken at any zenith view angle to an equivalent isothermal (or aerodynamic) surface temperature. With data from one day a...

Directional radiometric surface temperatures (Tr) obtained through remote sensing can be incorporated into land surface models to estimate sensible and latent heat fluxes (H and LE, respectively) from vegetated surfaces. The simplest approach assumes the difference between Tr and the air temperature near the surface (Ta) is proportional to the sens...

Conversion of radiometric land surface temperature (r) to an equivalent isothermal (aerodynamic) surface temperature (i) is important in balancing the land surface energy budget with satellite-based r measurements. An analytical land-atmosphere radiometer model (ALARM) has been developed to convert r taken at any zenith view angle to i at a specifi...

The Analytical Land-Atmosphere-Radiometer Model (ALARM) was developed to reconcile the land surface temperature measured by a radiometer with the surface temperature needed to give the correct sensible heat flux, H, at a specified value of the scalar roughness length. ALARM incorporates an exponential vertical temperature profile, uses K-theory for...

Measuring the tempospatial variability of saturated hydraulic conductivity (Ks) is time consuming, expensive, and encounters many uncertainties. This work aimed to develop a new model (REPM, Relative Effective Porosity Model) that estimates Ks from relative effective porosity (φer) and then compare it with a model (EPM, Effective Porosity Model) th...

Engineering and modeling applications often require reasonable estimates of the upper and lower limits of plant extractable water. Laboratory measurements of these limits do not always coincide with field observations. Statistical models to estimate soil water retention can be complicated, and usually are not based on field measurements. The object...

Improving the soil environment for seedling emergence and plant growth is possible using a good tillage system. From March 1993 until June 1994, the effect of tillage system and plant residue incorporation practices on the bulk density and the soil strength of the surface layer of a vertisol (very fine, smectitic, thermic, chromic Haploxerert), on...

Understanding of the effect of tillage and plant residue incorporation on infiltration rate during plant growth is vital to improve tillage–plant residue management practices, especially in vertisols. These soils may shrink and swell markedly which, in turn, affects their physical properties. From 1992 to 1994, the effect of two tillage practices a...

A study was carried out to determine the effects of different tillage and plant residue management practices on different soil moisture and shrink-swell properties of a Vertisol (very fine, semctitic, thermic, chromic Haploxerert (with less than 1 % slope). The core samples were collected in July (after harvesting of lentil) and in November (after...