The best design of subsurface trickle irrigation systems requires knowledge of water and salt distribution patterns around the emitters that match the root extraction and minimize water losses. The transient distribution of water and salt in a two-dimensional homogeneous Iraqi soil domain under subsurface trickle irrigation with different settings of an emitter is investigated numerically using 2D-HYDRUS software. Three types of Iraqi soil were selected. The effect of altering different values of water application rate and initial soil water content was investigated in the developed model. The coefficient of correlation (R2) and the root-mean-square error (RMSE) was used to validate the predicted numerical result. This statistical analysis revealed that there was no much difference between the predicted numerical results, and the measured values. R2 varied from 0.75 to 0.93 and the (RMSE) from 0.079 to 0.116. The comparison confirms the accuracy of the developed model, and it shows that it can be used to simulate the front wetting patterns of water and salt distribution under subsurface trickle irrigation systems. The simulation outcome showed that as the distance from the emitter increased, soil salinity far from the emitter decreased. As expected, irrigation duration and amount affects the dimension of the solute distribution.
In recent years, there is more interest in water sources availability, including groundwater due to an increase in demand for water because of the increasing population in the world, and the water recedes due to climate change also. Therefore, the study of groundwater has required more attention. The aim of the present study is to establish a MODFLOW model in the groundwater modeling system software to simulate the movement of groundwater in the Turssaq alluvial fan which is located in the Qazaniyah city, east of Diyala Governorate. The solid model was used to define the aquifer in the study area. Using the GIS software, mapping and preparing the data needed to create a conceptual model were carried out. The data of the
... Show MoreThis study was conducted from February 2010 to December 2010. Water Samples were collected every two months in three stations in Baghdad city. The study involved the assessment of concentrations of some heavy metals such as: Chromium, Cadmium, Copper, Iron, Lead, Manganese, Nickel and Zinc. the values of chromium were undetected for the entire of the study, while the rest of the heavy metal were ranged between 0.001 -0.438 mg / l, ND -0.077 mg / L, ND -0.778 mg / l, 0.36 - 0.011 mg / l, 0.011-0 .08mg/ l, ND - 0.1985 mg / l, ND -0.0416 mg / l, respectively. The results showed that the concentrations of heavy metals were fluctuated during the study period, except Lead which have high concentrations and exceeded the permit limits in all statio
... Show MoreGumbel distribution was dealt with great care by researchers and statisticians. There are traditional methods to estimate two parameters of Gumbel distribution known as Maximum Likelihood, the Method of Moments and recently the method of re-sampling called (Jackknife). However, these methods suffer from some mathematical difficulties in solving them analytically. Accordingly, there are other non-traditional methods, like the principle of the nearest neighbors, used in computer science especially, artificial intelligence algorithms, including the genetic algorithm, the artificial neural network algorithm, and others that may to be classified as meta-heuristic methods. Moreover, this principle of nearest neighbors has useful statistical featu
... Show MoreThis work focused on anthropogenic influences of the trace metals distribution in the soils of Kirkuk city. Sequential extraction technique was used to determine the distribution of the chemical fractions of Ag, Cd, Co, Cu, Ni, Pb, Zn, As, Cr and V in soil of Kirkuk city. This area is affected mainly by burning oil trash. Results show that these heavy metals were primarily restricted to surface horizons and mostly associated with the residual fraction (28.8 – 50%). The remnant fractions (13.8 – 33.1%) linked to the organic matter, 7.9 – 27.2% was bound to Fe-Mn oxide, 0.7 – 27.9 was bound to carbonate. Only a small amount of the total metals in the soil is exchangeable (0.5 – 4.2%) and water soluble (0 – 4.1%) fractions.
... Show MoreHigh tunnels, or unheated plastic greenhouses, are becoming increasingly popular among organic vegetable growers across the United States. However, the intensive production typical of these systems presents soil health challenges, including salinization due to high fertilizer or compost inputs coupled with lack of rainfall to leach salts. Legume cover crops may improve soil health in high tunnels by reducing the need for external inputs, while adding organic matter. We tested the soil health effects of a winter hairy vetch (Vicia villosa Roth) cover crop used to replace fertilizer N in an organic tomato cropping system in high tunnels. Studies were replicated across three sites differing in climate and soil type (Kansas, Kentucky, and Minne
... Show MoreCyanobacteria are prokaryotic photosynthetic communities which are used in biofertilization of many plants especially rice plant. Cyanobacteria play a vital role to increase the plant's ability for salinity tolerance. Salinity is a worldwide problem which affects the growth and productivity of crops. In this work three cyanobacteria strains (Nostoc calcicola, Anabaena variabilis, and Nostoc linkia) were isolated from saline soil at Kafr El-Sheikh Governorate; North Egypt. The propagated cyanobacteria strains were used to withstand salinity of the soil and increase rice plant growth (Giza 178). The length of roots and shoot seedlings was measured for seven and forty days of cultivation, respectively. The results of this investigation showed
... Show MoreThere are many aims of this book: The first aim is to develop a model equation that describes the spread of contamination through soils which can be used to determine the rate of environmental contamination by estimate the concentration of heavy metals (HMs) in soil. The developed model equation can be considered as a good representation for a problem of environmental contamination. The second aim of this work is to design two feed forward neural networks (FFNN) as an alternative accurate technique to determine the rate of environmental contamination which can be used to solve the model equation. The first network is to simulate the soil parameters which can be used as input data in the second suggested network, while the second network sim
... Show MoreThis review focuses on conservation agriculture (CA) and its effects on increasing the soil’s resistance to erosion. CA involves minimum soil disturbance (minimum tillage/ no-till), diversified crop rotation, and maintenance of the soil cover to increase soil fertility and reduce erosion. CA reduces soil loss by up to 90% and water erosion by approximately 50 to 70% from runoff as it increases the health of the soil, yield of crops, and water-retention capacity of the soil by incorporating soil organic matter and promoting biodiversity. Crop rotation prevents the replenishment and depletion of soil nutrients by atmospheric fixation of nitrogen/biological nitrogen fixation. Controlled traffic farming (CTF) is a new strategy in which travel
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