According to soil interpretation guide line, the major nutrient status (i.e. phosphorus, nitrogen, organic matter and potassium) are medium to high category. The soil physic-chemical properties status, at P<0.05 have shown significance difference between distances from the factories however no significance difference can occurs among soil depths. This might be due to the cement dust that changes the nutrient status of the top soil. The raw materials for cement productions (Limestone, clay, pumice, sandstone, gypsum, imported furnace oil and Kraft paper) might contribute to change soil physic-chemical properties of the top soil. Therefore, the factories should be subject to mandatory monitor and control the cement dust not to be polluting the agricultural fields and environment as well.
A pot experiment was conducted during September–December, 2013, in Department of Weed Science, The University of Agriculture Peshawar Khyber Pakhtunkhwa, to investigate the impact of soil moisture and various soil depths on the resprouting ability of Johnson grass (Sorghum halepense L.) rhizome fragments. The experiment was conducted in RCB design with split plot arrangement having three replications. The pot size was 10 inches. Each pot was filled with soil (mixture of sand silt and clay). The fresh rhizomes collected from infested fields were cut into pieces each having 3-4 eyes (about the pieces that usually a rotavator cuts). These pieces were buried in pots at depths of 2, 4 and 6 inches from soil surface in the pot.
ABSTRACT: Water scarcity, its necessity in food production, and environmental protection in the world have forced human beings to seek new water sources. Nowadays, application of unconventional water resources (wastewater) has been proposed in countries facing the crisis of water resources shortage; however, a few studies have dealt with this issue. The present study has evaluated the changes in the elements of the soil, irrigated with wastewater. For so doing, an experiment has been conducted on a randomized complete block design with three replications. Soil samples have been collected from the studied regions at two depths of 0-30 cm and 30-60 cm and the studied parameters have included sodium, total calcium, magnesium, some acidity, and electrical conductivity of the soil. Three regions of study (namely no irrigation, irrigation with treated wastewater, and irrigation with river waters) have been taken into consideration. Results have shown increased calcium, magnesium, and pH of the effluent from Zabol Wastewater Treatment Plant compared to the control; however, electrical conductivity and chloride have decreased in wastewater-irrigated soil. The electrical conductivity in the surface layer of wastewater samples, treated with an amount of 2.25 (ds/m), has had the most significant difference to the control and other treatments. It can be concluded that wastewater increases some soil properties, contributing to its restoration.
Reports by Mohamadinia, (1995) and Gandomkar, (1996) showed that using household and compost can increase the amount of absorbable magnesium within the soil based on the amount of the consumed compost leachate. Based on the same reports, time and wash can reduce the ability of soil to intake magnesium. If acidity increases, time and wash can reduce the ability of soil to intake magnesium. An increase in acidity will intensify the activities of Magnesium, magnesium, and aluminum ions (Panahpour, 2009). The difference between the different irrigation treatments reveals that in cycling treatment the Magnesium absorbency has been increased compared to the instance (Well irrigation). So the average leachate in Magnesium absorbency has increased from 22.63 in instance to 66.53 mg/kg in the alternation treatment.
MATERIALS AND METHODS A ﬁ eld experiment using a method of long belts was established in 1997 on experimental basis at Slovak Agricultural University (SUA) in Nitra – Kolíňany (university agricultural farm). The experiment was conducted on the base of a contract between the Duslo Šaľa, P.L.C. (mineral fertilisers producer) and the Department of Agrochemistry of the SUA in Nitra. The main goal of the experiment was to observe the eﬀ ect of mineral fertilisers (N-P-K, without organic fertilising) on six model crops yield (winter wheat, spring barley, silage maize, sugar beet, winter oilseed rape and sunﬂ ower). The pilot experiment was established on Haplic Luvisol and Stagni-Haplic Luvisol with the various humus horizon thickness (from 0.23 m to 0.45 m) and with diﬀ erent depths of ground water (2.0 m at the top of the slope and 0.7 m–1.0 m in the valley below the slope) in the maize growing region, 12 km east of Nitra on 14 ha area (324 × 432.2 m). Each nutrition option was assigned on 0.54 ha area (18 m × 300 m); the area for one crop was 2 ha. Weed infestation of winter wheat, spring barley, maize and sugar beet as well as and weed seed bank since 2000 year till 2002 year were investigated. There were three mineral fertilising options: variant 1 – not fertilised (control = a negative balance of nutrients in the soil, e.g. 0 kg N, P, K); variant 2 – N-P-K fertilising according to the plant’s requirements (steady balance of nutrients in the soil = fertilising as if for 5 t yield of cereal), variant 3 – high doses of N-P-K fertilisers (positive balance of nutrients in the soil = fertilising as if for 8 t of cereal). Concrete doses of mineral nutrients on variants 2 and 3 were applied as follows (per 1 ha in pure nutrients altogether): Variant 2 – winter wheat: 77.6 kg N, 25 kg P, 100 kg K; spring barley: 32.6 kg N, 25 kg P, 100 kg K; maize: 123.6 kg N, 31.2 kg P, 138 kg K; sugar beet: 54.5 kg N, 28 kg P, 120 kg K. Variant 3 – winter wheat: 120.1 kg N, 40 kg P, 160 kg K; spring barley: 55.1 kg N, 40 kg P, 160 kg K; maize: 199 kg N, 52 kg P, 230 kg K; sugar beet: 103.8 kg N, 45.5 kg P, 195 kg K.
Distribution of water-stable aggregation. Soil aggregate fractions of different vegetation types are shown in Figure 1. The averaged < 0.25 mm aggregate fractions of five vegetation types were 89.3, 80.7 and 91.8% for 0–20, 20–40 and 40–60 cm soil depths, respectively. It indicates that the mi- cro-aggregates (< 0.25 mm) were more stable and persistent. The possible reason probably was that macro-aggregates (> 0.25 mm) in highly erodible soil in Loess Plateau were prone to cause aggre- gate slaking and such aggregates could readily disintegrate into smaller units. Similar results were obtained by Huang et al. (2010), which sug- gested that macro-aggregates (> 0.25 mm) fractions from severely eroded Ultisols decreased with the increase of particle sizes compared with slightly and moderately eroded Ultisols.
Abstract: Weed seedbank is an indication of future weed infestation potential of the species and is essential for making strategic planning for its sustainable management. Parthenium weed (Parthenium hysterophorus L.) is an invasive alien species threatening the biodiversity and the environment in Malaysia. A study was, therefore, conducted to estimate the soil seedbank of the weed at four soil depths of four villages of Kuala Muda, Kedah. The aim was to indicate the critical s of parthenium weed seedbank in Malaysia. Soil samples were collected from the sites using a soil core. The seeds were extracted from the soil samples with sieve shaker at the Universiti Malaysia Kelantan laboratory, Jeli Campus. The study indicates that the weed seedbank is in critical level at the area. The highest number of weed seeds (6915/m 2 ) was found in Kg. Kongsi 6, followed by Kg.
Soil cover plants are considered an excellent alternative to decompress and improve soil structure, reaching a physical quality satisfactory . The use of decompressing plants composes an important management strategy in intensive production systems . However, the response is dependent on the cultivated plant ; because each root system presents a differentiated capacity of devel- opment in the soil. However, cover plants with good root development are able to act more uniformly in all soil depths when compared to mechanical systems, contributing more efficiently to the improvement of soil aggregation , thus presenting advantages over the use of agricultural implements, which can pro- mote the disintegration of soil structures.
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ABSTRACT: The objectives of this study were to investigate soil type, potentiality and reaction in relation to the scattered remaining vegetation species, and to quantify soil suitability for growing field crops. Adham area witnessed serious land degradation due to the rapid expansion of Rain-fed Mechanized Farming and overgrazing. Consequently, the low crop yield enforced the local communities to shift to the alternative sources of income generating activities, particularly those related to forest products like charcoal making, firewood production, logging and tree lobbing. By using Randomized Complete Block Design (RCBD), with emphasizes on Macro nutrients, particularly the Nitrogen, Phosphorous and potassium (NPK) in addition to soil pH and Electrical Conductivity (EC.), random soil samples, each with three levels of depths (0 - 15, 15 - 30, 30 - 45 cm.) were collected. All collected data were analyzed in the laboratory. The result of revealed several types of soils including the cracking and non -cracking clay, sandy, and red soils. The result of statistical analysis depicted variability in NPK, pH and EC between the different locations and soil depths. Furthermore, the result showed an association between some studied soil attributes and the spatial distribution of the vegetation species. Rational use through participatory approach is recommended for natural resources management, conservation and sustainability. Moreover, further study using space technology also recommended.
As an example, a situation could occur where an actual rock outcrop, low frequency input to a FEM does not produce as much top-of-soil response as the actual soil column (due to the FEM stiffness not being exactly correct). To reduce the top-of-soil discrepancy, more input low frequency content can be added (for either linear or nonlinear FEMs). For a linear FEM, the inaccuracy that this produces is limited to the low frequency content that has been modified. For the nonlinear model, this could additionally cause inaccuracies at higher frequencies. Adding additional high frequency content to correct the higher frequency inaccuracies could lead to inaccuracies at yet higher frequencies. Attempting to address all the resulting inaccuracies could produce an unreasonably inaccurate input time series. Considering this example, few iterations are performed on the nonlinear model and an inexact result that is close to the real top-of-soil motion is considered acceptable.
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for soil–plant–atmosphere systems (COUP) (Jansson 2001; Jansson and Karlburg, 2010), and the distributed water–heat coupled (DWHC) model (Chen et al., 2007) have large pa- rameter and forcing data requirements – such as wind speed, relative humidity, and short- and long-wave radiation – which restricts their applicability in many watershed. Additionally, these types of models either include, or are tightly coupled to soil moisture models, which can limit their applicabil- ity in models that do not explicitly simulate soil moisture content. To reduce data and parameter requirements and in- crease applicability, simple temperature-index or degree-day methods (Molnau and Bissell, 1983; Rekolainen and Posch, 1993) remain widely used within watershed models, includ- ing LISFLOOD (De Roo et al., 2001; Van Der Knijff et al., 2010), CREAMS (Rekolainen and Posch, 1993), and the gridded surface subsurface hydrologic analysis (GSSHA) model (Downer and Ogden, 2004). Degree-day approaches typically accumulate the daily average temperature as a frost index ( ◦ C-days). When the frost index exceeds a threshold, the soil is considered frozen and impermeable to infiltra- tion. The sudden restriction on infiltration can be an incor- rect assumption, especially in forested environments where frozen soils often still experience infiltration (Lindstrom et al., 2002; Nyberg et al., 2001; Shanley and Chalmers, 1999). A limitation of degree-day approaches is that they are of- ten untested against observed frost data because the frost in- dex is not a physical property that can be compared to mea- surements. However, degree-day methods have been success- ful in capturing increased runoff from frozen ground events (Molnau and Bissell, 1983), and higher frost index values have been shown to correlate to deeper frost depths (Vermette and Christopher, 2008; Vermette and Kanack, 2012). Spatial variations of frozen ground within degree-day methods are typically based on variations in temperature (which are esti- mated from an elevation–temperature relationship) and vari- ations in snowpack insulation (which are also typically in- ferred from an elevation–temperature relationship). Such re- liance on elevation may lead to errors because Stähli (2017) found no clear connection between elevation and presence of frozen ground at test sites in the Swiss pre-Alpine zone.
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Saharan et al.  observed maximum seedling emergence (70%) in soil having 1:2:1 ratio of Sand:Clay:FYM in E. alsinoides. Swami and Kasera  documented that seeds of Withania somnifera sown at 0.5 cm depth with 1:2:1 soil mixture ratios of Sand:Clay:FYM showed optimum seed germination, plant growth and biomass production. Cent percent seedling emergence in Asparagus racemosus at 0.5 cm depth with 1:2:1 ratios of Sand:Clay:FYM was reported by Raghav and Kasera.  Thus, soil mixture ratio with higher clay and FYM were found to be good for germination and seedling growth in D. erythraeum, as supported by findings of above researchers. Mathur and Sundaramoorthy  obtained better yield of biomass per plant in clay soil as compared to other soil mixtures in Blepharis sindica. The response of FYM application can be attributed to the better nutrient availability due to the better absorption and assimilation and its favourable effect on physical and biological properties of soil, resulting in an increased growth and yield.
Data analysis and statistics. The T-RFs which matched with sequences in the clone library in each P treatment were defined as valid T-RFs. The T-RF matrix in each sample was constructed by the presence/absence of individual T-RF. T-RF richness (S) was represented by the total number of T-RFs in soil or maize roots at three growth stages under different P treatments. Significant differences among soil physico-chemical proper- ties, infection indexes and diversity indexes of AMF were tested by one-way analysis of variance followed by comparison between pairs of mean values using Duncan’s multiple range test. Two-way analysis of variance was used to analyze the main and interactive effects of P fertilization and soil depth on each soil chemical property and AMF infection index. We assessed relationships between richness and soil chemical variables by calculating the Pearson’s correlation coefficients. All statistical analyses were performed using SPSS 13.0 (SPSS Inc., Chicago, IL). Canonical correspondence analysis (CCA) was performed to analyze the influence of P fertilization treat- ments and soil physico-chemical properties on soil AMF community composition. Principal component analysis (PCA) was explored to analyze the influence of P fertilization and maize growth stage on root AMF community structure. Ordination analyses and hypothesis testing were conducted in CANOCO for Windows v. 4.5 with binary-transformed data. In addition, forward selection tests were conducted using 499 permutations and the Monte Carlo permutation test with p < 0.05 was used. Biplots were created using CanoDraw 4.5 to display the ordination results.
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Microwave with high frequency, normally 2.45 GHz, can create non-ionizing electromagnetic radiation and let polar molecules such as water rotate extremely (i.e., dipole rotation or dipolar polarization) and rapidly raise material temperature. Consequently, microwave accompanied with strong acid is often applied to decompose metal-organics in sludge, soil and sediment digestion [8−12]. Therefore, microwave with quick thermal decomposition characteristics can be employed for rapidly treating organic contaminant and this new remediation method have been studying at laboratories for developing a future practical technology . In this paper, a petroleum products contaminated soil sampled from a gas station was studied for evaluating the feasibility of microwave remediation.
very close to the most common experimental results (see, for example, Sharma et al., 1981; Fohrer et al., 1999) and was frequently used in order to test a few specific models for infil- tration in crusted soils (see, for example, Hillel and Gardner, 1970; Ahuja, 1983). The upper limit is linked, as pointed out by Mualem and Assouline (1989), with the extension of the region where changes in soil properties might be considered relevant, particularly under conditions of unsaturated sur- face. Values of the order of some centimetres were adopted by Mualem et al. (1993) and Assouline and Mualem (1997) for different soil types. In spite of the wide variability in sealing layer thickness reported in literature was explained by Assouline and Mualem (2000) through the different reso- lution used in measuring the soil bulk density, the uncertainty in seal thickness justifies the necessity to quantify its role in this study. For each representative event of Table 2, using the same procedure adopted with Z c = 5 cm we have simu-
Eq. (1) is a non-linear differential equation which normally requires complex numerical schemes such as the finite element method to solve it (Šimunek et al., 1992). This involves the procedures of solving a series of linear equations simultaneously in both temporal and spatial domains, resulting in long computer codes which are often associated with the problem of numerical stability. In this study, a simple procedure using an integration strategy of Eq. (1) over the soil layers is employed. The model considers that water content in a soil layer is only influenced by the above and below layers in a small time step, which drastically simplifies the algorithm, allowing soil water flow to be calculated layer by layer. The procedure differs from that by Lee and Abriola (1999) in the form of the Richards equation. Lee and Abriola (1999) used the soil water content based flow equation, which is not applicable to simulate water flow between different soils. This problem is overcome by using the soil pressure head based flow equation as formulated in Eq. (1).
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Differences at Samoylov are more related to the snow depth biases. As previously mentioned, subcritical snow con- ditions at this site amplify the soil temperature overestima- tion coming from snow depth bias (Fig. 5). Considering their better match during snow-free season (Fig. 6c), the warmer temperatures in deeper layers of JULES and COUP can be attributed to overestimated snow depths for this site by these two models (Fig. 9). Additionally, JULES and COUP mod- els simulate generally warmer soils conditions than the other models, because these models include heat transfer via ad- vection in addition to heat conduction. Heat transfer by ad- vection of water is an additional heat source for the subsur- face in JULES and COUP, which can also be seen in the re- sults for Bayelva (Fig. 10). In combination with that, COUP has a greater snow depth at Samoylov (Fig. 5), resulting in even warmer subsurface conditions than JULES. Such con- ditions demonstrate the importance of the combined effects of surface processes together with internal soil physics.
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Heat is transferred through the ground slowly, as the ground is often a thermal conductor. The amplitude of a diurnal variation of soil temperatures decreases exponentially with the depth (Fig. 1). It is significant down to the soil depth of one meter for an annual surface temperature change due to the seasonal variation. Daily temperature variations at the surface are also substantially reduced and the typical e- folding scale depth for this is about 0.15 m for rather dry soil (Arya, 1988). Therefore, the meteorological parameters affect mostly the near surface soil; however, the energy of earthquakes often affect the ground at the deeper part. As a result we consider the ground temperature variation at a one meter depth as a short time (about a few days) earthquake precursor. The Alborz region is selected because of: the high potential for seismic activities, the large number of active and seismic faults, the high density population and the adjacent cities near the active main faults (Fig. 2). The ground tem- perature value, down to one meter, during a 12 years period
Santa Cruz 47, and thinning was performed when plants showed three definitive leaves, leaving one per hole. At 22 days after sowing (DAS), fertigation was applied using 15 g of potassium chloride and 31 g of urea per plant and again at 42 DAS, using the same doses. The adopted spacing was 1 m between rows and 0.4 m between plants, and the soil was covered at 40 DAS with residues of dehydrated silage of maize (Zea mays) and elephant grass (Pennisetum purpureum Schumach), covering an area of 40 cm 2 . Plant water supply was daily provided based on the Class-A pan evaporation of the previous day, using a localized drip irrigation system with flow rate of 8.5 L h -1 , and the experiment was divided into two areas, corresponding to each irrigation depth.The time of irrigation was controlled through valves. Irrigation monitoring (Mantovani et al., 2009) was as follows: DNID = ETo x Kc; DNID = daily net irrigation depth; ETo = reference potential evapotranspiration, in mm; Kc = crop coefficient; NDI= ETc x AE(P/100);NDI = L plant -1 day -1 , AE = spacing between plants, flow rate per plant (L h -1 plant -1 ) = q(AP/AE), q = emitter flow rate, AP = area of the plant, AE = spacing between plants, time of irrigation (L/H/Plant) = NIDx(7/J)/Q; J= weekly working hours, Q = flow rate per plant. The values of Kc were 0.68 and 0.79 in the first 40 DASand from 40 to 70 DAS, referring to the first and second stages, respectively (Paes et al., 2012).
organizer through soil column deconvolution showed shear modulus reductions greater than 90% near the ground surface. The largest shear strain of the soil column was actually 0.72% which is largely beyond the commonly admitted limit of 0.1% soil strain (ASN, 2006) and yet the numerical results based on this model were in good agreement with the recorded in-structure responses. We think it is reasonable to restraint the maximum soil strain to 0.8% in our study. This means that all input signals which create soil strain beyond this threshold will be eliminated from the simulation. We can thus expect that the input signals used in the simulations will not exceed significantly the site-recorded motions in terms of intensity.
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