Restoration of degraded lands by adoption of recommended conservation management practices can rehabilitate watersheds and lead to improving soil and water quality. The objective was to evaluate the effects of grass buffers (GBs), biomass crops (BCs), grass waterways (GWWs), agroforestry buffers (ABs), landscape positions, and distance from tree base for AB treatment on soil quality compared with row crop (RC) (corn [Zea mays L.]–soybean [Glycine max (L.) Merr.] rotation) on claypan soils. Soil samples were taken from 10‐cm‐depth increments from the soil surface to 30 cm for GB, BC, GWW, and RC with three replicates. Soil samples were collected from summit, backslope, and footslope landscape positions. Samples were taken at 50‐ and 150‐cm distances from the tree base. β‐Glucosidase, β‐glucosaminidase, dehydrogenase, fluorescein diacetate hydrolase (FDA), soil organic carbon (SOC), total nitrogen (TN), active carbon (AC), and water‐stable aggregates (WSA) were measured. Results showed that β‐glucosidase, β‐glucosaminidase, dehydrogenase, FDA, AC, WSA, and TN values were significantly greater (P < 0.01) for the GB, BC, GWW, and AB treatments than for the RC treatment. The first depth (0–10 cm) revealed the highest values for all soil quality parameters relative to second and third depths. The footslope landscape had the highest parameter values compared with summit and backslope positions. The 50‐cm distance of AB treatment had higher values than the 150‐cm distance for all measured parameters. Results showed that perennial vegetation practices enhanced soil quality by improving soil microbial activity and SOC.
Core Ideas
Permanent vegetative management (trees and grasses) enhanced soil quality.
Perennial practices improved microbial activity and increased soil organic carbon.
Perennial vegetative practices have agricultural and environmental significance.
Establishing perennial practices is an effective approach to enhance soil quality.
Isolated Bacteria from the roots of barley were studied; two stages of processes Isolated and screening were applied in order to find the best bacteria to remove kerosene from soil. The active bacteria are isolated for kerosene degradation process. It has been found that Klebsiella pneumoniae sp. have the highest kerosene degradation which is 88.5%. The optimum conditions of kerosene degradation by Klebsiella pneumonia sp. are pH5, 48hr incubation period, 35°C temperature and 10000ppm the best kerosene concentration. The results 10000ppm showed that the maximum kerosene degradation can reach 99.58% after 48 h of incubation. Higher Kerosene degradation which was 99.83% was obtained at pH5. Kerosene degradation was found to be maximum at 3
Trickle irrigation is a system for supplying filtered water and fertilizer directly into the soil and water and it is allowed to dissipate under low pressure in an exact predetermined pattern. An equation to estimate the wetted area of unsaturated soil with water uptake by roots is simulated numerically using the HYDRUS-2D/3D software. In this paper, two soil types, which were different in saturated hydraulic conductivity were used with two types of crops tomato and corn, different values of emitter discharge and initial volumetric soil moisture content were assumed. It was assumed that the water uptake by roots was presented as a continuous sink function and it was introduced into Richard's equation in the unsaturated z
Ex-situ bioremediation of 2,4-D herbicide-contaminated soil was studied using a slurry bioreactor operate at aerobic conditions. The performance of the slurry bioreactor was tested for three types of soil (sand, sandy loam and clay) contaminated with different concentration of 2,4-D, 200,300and500mg/kg soil. Sewage sludge was used as an inexpensive source of microorganisms which is available in large quantities in wastewater treatment plants. The results show that all biodegradation experiments demonstrated a significant decreases in 2,4-D concentration in the tested soils. The degradation efficiency in the slurry bioreactor decreases as the initial concentration of 2,4-D in the soils increases.A 100 % removal was achieved at initial con
In this study, the relationship between the bare soil temperature with respect to its salinity is presented, the bare soil feature is considered only by eliminating all other land features by classifying the site location by using the support vector machine algorithm, in the same time the salinity index that calculated from the spectral response from the satellite bands is calibrated using empirical salinity value calculated from field soil samples. A 2D probability density function is used to analyze the relationship between the temperature rising from the minimum temperature (from the sunrise time) due to the solar radiation duration tell the time of the satellite capturing the scene image and the calibrated salinity index is presented. T
Transgenic plants offer advantages for the manufacture of recombinant proteins with terminal mannose residues on their glycan chains. So plants are chosen as source of pharmaceutical products and for the development of alternative expression systems to produce recombinant lysosomal enzymes. In the present study the sequence of the natural cDNA encoding for the human lysosomal enzyme glucocerebrosidase (GCD) was modified to enhance its expression in soybean plants. The glucocerebrosidase gene signal peptide was substituted with that signal peptide for the Arabidopsis thaliana basic endochitinase gene to support the co-translational translocation into the endoplasmic reticulum (ER), and the storage vacuol
Gypseous soil, which covers vast area in west, middle, east and south west regions of Iraq exhibit acceptable strength
properties when dry, but it is weak and collapsible when it comes in touch with moisture from rain or other sources. When such
weak soil is adopted for earth reinforced embankment construction, it may exhibit hazardous situation. Gypseous soil was investigated for the optimum liquid asphalt requirements of both cutback and emulsion using the one-dimensional unconfined
compression strength test. The optimum fluid content was 13% (7% of cutback with 6% water content), and 17% (9% of
emulsion with 8% water content). A laboratory model box of 50x50x25 cm was used as a representative of embankment; soil or
asphalt stabilize
The materials of soil were affected by multi reasons; such as human activities, floods, tidal waves, ... etc. The change of the soil contents could be measured through different indexes; such as electric conductivities, salinity, concentration of the heavy elements, and concentration of essential elements ... etc. The land cover is affected by natural influences, like tidal energy, which plays a negative role in the salinization of land adjacent to the coasts, causing a problem for soils in all its details represented in changing of the dissolved elements in soil. One of the most important natural factors that cause soil salinity is human activity in all its forms, and one of the most important causes of salinity is the phenomenon o
Gypseous soils are considered one of the most problematic soils. The skirted foundation is an alternative technology that works to improve the bearing capacity and reduce settlement. This paper investigates the use of square skirted foundations resting on gypseous soil subjected to concentric and eccentric vertical load with eccentricity values of 4, 8, and 17 mm in 16 experimental model tests. To obtain the results by using this type of foundation, a small-scale physical model was designed to obtain the load–settlement behavior of the square skirted foundation; the dimension of the square footing is 100 mm × 100 mm with 1 mm thickness, the skirt depth (D