Статті в журналах з теми "Calcareous soils Testing"

A study was conducted with five soil P tests (Bray P1 (1:10), Bray P1 (1:50), Mehlich II, Kelowna I and Kelowna II) to determine the effect of soil carbonates on postextraction pH and on the correlation between soil and plant P concentration. Alfalfa (Medicago sativa L.) was grown on five calcareous and six noncalcareous soils fertilized at 0 and 90 μg P mL−1 in a growth room experiment. The ability of the extradants to maintain a low pH with calcareous soils was poorest for the Bray P1 (1:10) followed by the Mehlich II, Kelowna I, Kelowna II and Bray P1 (1:50). The Bray P1 (1:10) did not give a statistically significant correlation coefficient between soil and plant P concentration with the calcareous soils, while the other methods did. Key words: Soil testing, calcareous soils, Bray P1, Mehlich II, Kelowna I, Kelowna II

The influence of the effective overburden pressure on the standard penetration test (SPT) values in calcareous desert sands is examined by field tests. A simple field testing procedure is proposed and employed in Kuwait at five sites having different relative densities for the surface soils. The correction factors for the SPT are determined from test results and compared with the most reliable correlations for clean silica sand. Key words: field tests, plate bearing tests, overburden pressure, standard penetration test, correction factors, relative density, calcareous soils, shear strength, compressibility.

A 3-year replicated fertility trial with four vegetable crops was begun in the 1993–94 season to: a) determine crop nutrient requirements for four vegetable crops (bush bean, malanga (Xanthosoma caracu), potato, and sweet corn, and b) to develop and calibrate a soil testing procedure for the local calcareous soils. Soils were found to test medium to high for both phosphorus and potassium. Responses to nitrogen varied by crop. Specific results and follow up trials with growers will be discussed.

Researchers use different methods to investigate and quantify clay minerals. X-ray diffraction is a common and widespread approach for clay mineralogy investigation, but is time-consuming and expensive, especially in highly calcareous soils. The aim of this research was prediction of clay minerals in calcareous soils of southern Iran using a feature selection algorithm and adaptive neuro-fuzzy inference system (ANFIS) methods. Fifty soil samples from different climatic regions of southern Iran were collected and different climatic, soil properties and clay minerals were determined using X-ray diffraction. Feature selection algorithms were used for selection of the best feature subset for prediction of clay mineral types along with two sets of training and testing data. Results indicated that the best feature subset by Best-First for prediction of illite was cation exchange capacity (CEC), sand, total potassium, silt and agroclimatic index (correlation coefficient (R) = 0.99 for training and testing data); for smectite was precipitation, temperature, evapotranspiration and CEC (R = 0.89 and 0.87 for training and testing data respectively); and for palygorskite was precipitation, temperature, evapotranspiration and calcium carbonate equivalent (CCE) (R = 0.98 for training and testing data). An attempt was made to predict clay minerals type by ANFIS using selected data from the feature selection algorithm. The evaluation of method by calculating root mean square error (RMSE), mean absolute error (MAE) and R indicated that the ANFIS method may be suitable for illite, chlorite, smectite and palygorskite prediction (RMSE, MAE and R of 0.001–0.028, 0.004–0.012 and 0.67–0.89 respectively for training and testing data). Comparison of data for all clay minerals showed that ANFIS method did not predict illite and chlorite as well as other minerals in the studied soils.

Recommendations made for nutrient applications have traditionally focused on economic yield and quality. However, present-day testing procedures and recommendations are required to simultaneously ensure economical and environmental sustainability of agricultural production systems. A soil test is a calibrated index relating crop response to applied nutrients. Any application rate devoid of an economical response in yield or quality is deemed unnecessary. Therefore, a soil test becomes the first step in any nutrient best management practice (BMP) development, implementation, and monitoring activity. Certain significant areas in Florida, such as calcareous soils, require development of calibrated soil tests rather urgently. Nutrient sufficiency of perennial crops and deficiency diagnostics can be gauged through in-season plant tissue testing. Nutrient delivery for correcting the deficiency through foliar sprays is not always effective, and may require multiple applications. Spectral reflectance methods show significant promise as an alternative to traditional wet chemistry analyses with regard to ease, costs, and speed with wider range of applications, including natural resources. Additional research is needed to develop this technology for field-scale applications. Current research is focusing on environmental nutrient management to include nutrient sources, application rates and timing, nutrient uptake efficiency, retention capacity of soils, estimating and minimizing nutrient losses to the environment, etc. Nutrient loss assessments tools such as the Florida phosphorus (P) index and bahia (Paspalum notatum) and citrus (Citrus spp.) tests for P are now being made possible in Florida through integration of soil and tissue testing methods. Development and improvements of such analytical methods and tools specific to Florida to include other nutrients, heavy metals, soil capacity, and ecosensitive regions, is vital to ensure sustainability to the state's tourism, agriculture, and urban-rural balance.

AbstractExperiments to explain the rise in the floor of a hospital built on calcareous black pyritic shales have substantiated the reported chemical changes which bring about the formation of selenite (gypsum) along bedding planes. The experiments have also indicated that the sulphate content of a weak rock is not constant and depends on the weathering state.If the long-term importance of sulphates is to be determined there is strong evidence that it is the maximum potential S03 or total sulphur that should be assessed as this would be more beneficial than simply acquiring the S03% as is currently done in most site investigations.Although BS5930 recommends that sulphate and pH testing is carried out as soon as possible after the sample has been taken, it does not give any cautionary note to indicate that the soil chemistry is likely to change with exposure. Experiments are described to show the effect of this change with time.

Preplant soil testing is essential for optimizing phosphorus (P) fertilization and minimizing the potential for soil P losses. Currently, there is no effective soil P extractant for calcareous soils in Florida. This study was conducted to compare Mehlich-3, ammonium bicarbonate–diethylenetriaminepentaacetic acid (AB-DTPA), and Olsen for evaluating P availability, estimating soil-test P (STP) critical levels, and calibrating P application rates for fresh-market tomato (Solanum lycopersicum L.) production in a calcareous soil. Tomatoes were grown during Winter 2014 and 2015 with P application rates of 0, 29, 49, 78, 98, and 118 kg·ha‒1 P. Water-extractable P (water-P) and dissolved reactive P (DRP) in leachate were used to determine the STP change point of leaching potential. Results showed the greatest correlation occurred between Mehlich-3 and Olsen of the three STP extractants. For Mehlich-3-P, the medium STP level (producing 75% to 90% relative yield) was predicted from 76 to 89 mg·kg‒1 and the change point was predicted at 88 or 104 mg·kg‒1 by split-line models. The P requirement was calculated from 52 to 112 kg·ha‒1 when Mehlich-3-P was rated as low level (producing 50% to 75% relative yield), which was from 42 to 76 mg·kg‒1. The multiple regression models using AB-DTPA-P and Olsen-P could not predict either the medium STP level or the practical P application rates for the low level. Consequently, based on 2 years of data, Mehlich-3 was the most effective extractant for estimating soil P availability and calibrating P rates in calcareous soils with an extremely high calcium carbonate (CaCO3) content.

Liquid forms of phosphorus (P) have been shown to be more effective than granular P for promoting cereal growth in alkaline soils with high levels of free calcium carbonate on Eyre Peninsula, South Australia. However, the advantage of liquid over granular P forms of fertiliser has not been fully investigated across the wide range of soils used for grain production in Australia. A glasshouse pot experiment tested if liquid P fertilisers were more effective for growing spring wheat (Triticum aestivum L.) than granular P (monoammonium phosphate) in 28 soils from all over Australia with soil pH (H2O) ranging from 5.2 to 8.9. Application of liquid P resulted in greater shoot biomass, as measured after 4 weeks’ growth (mid to late tillering, Feeks growth stage 2–3), than granular P in 3 of the acidic to neutral soils and in 3 alkaline soils. Shoot dry matter responses of spring wheat to applied liquid or granular P were related to soil properties to determine if any of the properties predicted superior yield responses to liquid P. The calcium carbonate content of soil was the only soil property that significantly contributed to predicting when liquid P was more effective than granular P. Five soil P test procedures (Bray, Colwell, resin, isotopically exchangeable P, and diffusive gradients in thin films (DGT)) were assessed to determine their ability to measure soil test P on subsamples of soil collected before the experiment started. These soil test values were then related to the dry matter shoot yields to assess their ability to predict wheat yield responses to P applied as liquid or granular P. All 5 soil test procedures provided a reasonable prediction of dry matter responses to applied P as either liquid or granular P, with the resin P test having a slightly greater predictive capacity on the range of soils tested. The findings of this investigation suggest that liquid P fertilisers do have some potential applications in non-calcareous soils and confirm current recommendations for use of liquid P fertiliser to grow cereal crops in highly calcareous soils. Soil P testing procedures require local calibration for response to the P source that is going to be used to amend P deficiency.

A field experiment is conducted to study the effect of different levels of peat (0, 25, 50, 75, and 100 Mg ha-1 to uncropped and cropped soil to wheat. Soil samples are taken in different period of time (0, 3, 30, 60, 90, 120, and 180 days after cultivation to determine (NaHCO3-Exteractable P at 3 different depths (0-10, 10-20, and 20-30 cm). Field Experiment is conducted in a randomized complete block design (RCBD) with four replicates. Wheat, Al-Rasheed variety, is cultivated as a testing crop. The entire field is equally dived in two divisions. One of the two divisions is cultivated to wheat and the second is left uncropped. The effect of five levels of peat namely 0, 25, 50, 75, 100 Mg ha-1 is investigated. Soils are fully analyzed to determine its physical and chemical characteristics. The soil samples are collected after 3, 30, 60, 90, 120, and 180 days for determining essential parameters and indicators that reflect the effect of the level of peat applications. Sodium bicarbonate - extractable P in uncropped and cropped soils at all depths, markedly decreases with time after peat application which has been attributed to plant uptake and rapid reaction of P with soil constituents. Sodium bicarbonate - extractable P with time in soil receiving 50 Mg ha-1 in both uncropped and cropped soil linearly decreases with the time of cultivation

A greenhouse experiment was conducted to evaluate several P availability parameters using 17 soils from the Peace River region of northwestern Canada. Only one soil was calcareous; the rest were acidic. The extractants tested included alkaline bicarbonate, acidic fluoride and 0.01 M CaCl2 solutions, and an anion exchange resin. Other availability indices evaluated were phosphoric acid potentials, phosphate buffer capacity and single point P sorption indices. The phosphoric acid potentials gave the highest correlation with percent relative yield of barley dry matter obtained after about 7 wk of growth. P sorption indices were not correlated with any crop response index. The phosphate buffer capacity and resin-extractable P performed at least as well as three chemical extractants: Olsen, Kelowna and Miller-Axley (modified) extractants. These three extractions were further evaluated using yield data from 11 field experiments with barley and 10 with rapeseed. There was little to choose from between these three extractants; however, the Kelowna extractant is a multi-element extractant and more convenient to use than the Olsen method. The Kelowna extractant also has a better buffering capacity, thus giving it a slight advantage over the modified Miller-Axley method for calcareous soils. These soil tests are, however, not fully satisfactory. In the greenhouse study, the Kelowna and Olsen methods made two errors and the modified Miller-Axley method three errors in prediction of P fertilizer requirement or non-requirement for the experimental soils. Key words: Soil testing, phosphate potential, chemical extractants, P sorption index, critical level

This work aimed to understand the mechanical behavior of siliceous and calcareous sand materials under uniaxial confined compression loading at high stress levels. For this purpose, a series of quasi-oedometric compression tests were conducted on sand materials, to examine the effects of grain size, nature, and moisture contents on the soil crushability and the compression behavior, using an upgraded thick pressure vessel device that can reach mean stress up to 500 MPa. All samples were prepared using an aspect ratio of 1:1 (diameter: height), placed inside a high strength steel vessel, and compressed at a uniform axial displacement rate of 5 µm/s. The vessel is instrumented with multiple strain gauges allowing for the characterization of the hydrostatic and deviatoric behavior of each test. The results of quasi-oedometric tests, conducted on these types of sand, up to a passive confinement of 500 MPa, show that particle breakage is enhanced by the presence of water. It was noticed that, for siliceous sand, smaller particles break more than larger particles, and that the calcareous grains manifest a rapid response to axial stress compared to siliceous sand. Testing various soil properties shows a great potential to better characterize the sensitivity to breakage of soils. Lastly, a post-mortem analysis of samples before and after testing, using the X-ray micro-tomography technique, was applied to study the mechanical damage of sand specimens.

Septic leach field design in the arid southwestern US requires direct testing of soils to ensure adequate drainage. We propose that direct testing costs can be reduced if electrical geophysical methods are used to determine soil structure that facilitates proper drainage rates. We demonstrate this concept at a residential site where resistivity and induced polarization data were acquired within a desert soil with variable mixtures of clay (Argid) and calcareous (Orthid) components. Electrode arrays were tested to ensure high data quality and minimal workload during inversion modeling. The resulting resistivity structure identified a sharp boundary between the eastern and western halves of the property. The west was more conductive than the east, which could indicate the presence of higher moisture or higher clay content. Chargeability data gathered from the induced polarization survey showed similar stark patterns between east and west halves of the property. The western portion of the survey area was verified to have some clay based on high chargeability values and direct soil testing from pits. Test pits dug to 3.65 m showed transitions between Argid and Othid conditions; the test pits were in locations of moderate resistivity and low chargeability. From this study, we concluded that resistivity and IP were useful in septic design because they reduce the total amount of direct testing needed when testing locations are carefully chosen based on the geophysical results.

Any variety needs to evaluate at different locations, along with variable soils for asses their yield potentiality after its releasing. Thus, an experiment was conducted at Multi Location Testing (MLT) site, Kushtia Sadar Upazila, under High Ganges River Floodplain (AEZ-11) in Bangladesh, during three consecutive Rabi seasons of 2013-2014 to 2015-2016. The objective of this study was to evaluate the performances of garlic varieties and economic profitability of these varieties at farmer’s field. There were three garlic varieties, namely BARI Rashun-1, BARI Rashun-2 and a local cultivar, which were evaluated at six dispersed locations as replications. Results observed that the highest yield (8.34-9.80 t ha-1) was obtained from BARI Rashun-1, which was followed by BARI Rashun-2 (7.43-9.48 t ha-1) and the local one (7.12-9.15 t ha-1). BARI Rashun-1 produced 3-12% higher yield over BARI Rashun-2 and 7-20% over the local cultivar, respectively in three consecutive years. Correlation analysis showed that there were positive and significant correlation among bulb yields with bulb length and individual bulb weight. Regarding the functional relationship, the traits like crop duration, plant population, plant height, bulb length, bulb width, individual bulb weight had positive contribution on the bulb yield. It was dependent on those traits, and accounted for 12, 36, 0.05, 45, 41 and 55% of the total bulb yield variation, respectively. The highest gross return (Tk. 3, 63,700 ha-1) and gross margin (Tk. 2,19,425 ha-1) were obtained from BARI Rashun-1. As such, this variety performed as the best, in respect of higher bulb yield potential, as well as the highest economic return among the tested varieties, which was followed by BARI Rashun-2. Therefore, the result of this study could be helpful for improving bulb production of garlic under High Ganges River Floodplain soil (calcareous soils) in Bangladesh.

Current soil classification systems based on cone penetration testing (CPT) utilize a combination of the tip resistance (qt), pore pressure (u2), and friction sleeve (fs) measurements as inputs. While the qt measurements are typically normalized by the overburden stress, the fs measurements are often normalized by the net tip resistance, leading to the use of parameters that are dependent on each other. This paper presents the development of a soil classification framework that utilizes a normalized multi-friction parameter (MFP) and the CPT normalized tip resistance. The MFP parameter is obtained from measurements with textured friction sleeves from soundings with multi-sleeve attachments. The use of textured friction sleeves allows for fundamental differences in soil–structure interface behavior and particle sizes to be captured due to the significant degree of shearing induced within the soil. This classification framework was developed with results from over 30 soundings at six different sites. The analysis of samples taken from the field indicates that the proposed framework provides a classification that better agrees with the grain-size distribution for residuum, calcareous and intermediate soils, as compared to existing CPT-based systems. The potential development of a simplified probe with just one additional friction sleeve sensor can provide appropriate classification results and would facilitate adoption for use in practice.

Leaf tissue testing is a useful tool for monitoring nutrient requirements in northern highbush blueberry (Vaccinium corymbosum L.; abbreviated as “blueberry”) but may require adaptation to specific growing environments. The objective of this study was to evaluate macronutrient concentrations in early-, mid-, and late-season blueberry cultivars grown in two contrasting environments, specifically eastern and western Washington. Climate and soil conditions between these two regions differ tremendously with eastern Washington being more arid with naturally calcareous soils lower in soil organic matter. Sampling was conducted over a 3-year period in commercial fields. Leaf tissue nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg) and sulfur (S) concentrations were affected by year (Y), growing region (R), cultivar (C), and Day of Year (DOY) that the samples were collected with many interactions. Leaf nutrient concentrations were higher, on average, in western than eastern Washington except for Ca and Mg, indicating sufficiency levels should differ between these regions. Leaf macronutrients generally stabilized between DOY 212–243 (1–31 August), suggesting this period is optimal for tissue sampling. Findings from this study demonstrate the importance of considering regional effects and may be applicable for blueberry cultivated in similar pedo-climactic conditions around the world.

This paper describes the foundation design process adopted for two high-rise buildings in Dubai, the Emirates Twin Towers. The foundation system for each of the towers was a piled raft, founded on deep deposits of calcareous soils and rocks. The paper outlines the geotechnical investigations undertaken, the field and laboratory testing programs, and the design process and describes how potential issues of low skin friction and cyclic degradation of skin friction due to wind loading were addressed. An advanced numerical computer analysis was used for the design process, which was carried out using a limit state approach. This necessitated analysis of a large number of load cases, and the paper describes how the information was processed to produce design information. A comprehensive program of pile load testing was undertaken, and class A predictions of both axial and lateral load–deflection behaviour were in fair agreement with the load test results. Despite this agreement, the overall settlements of the towers observed during construction were significantly less than predicted. The possible reasons for the discrepancy are discussed.Key words: case history, footings and foundations, full-scale tests, piles, rafts, settlement.

A new exploratory procedure for collecting continuous shear wave velocity measurements via cone penetration testing using a special autoseis source is presented whereby wavelets can be generated and recorded every 1 to 10 s. The continuous-interval seismic piezocone test (CiSCPTu) offers a fast, productive, and reliable means to expedite the collection of downhole shear wave velocity profiles, as well as additional readings on cone tip resistance, sleeve friction, and penetration porewater pressures with depth. A site in Windsor, Virginia, is utilized for illustrating the collection of data, calibration, and post-processing issues arising from large numbers of wavelets that require filtering, windowing, and selection in both time and frequency domain analyses. At the test site, the geology consists of shallow Holocene deposits of clays and sands to 8 m that are underlain by much stiffer calcareous sandy marine clay soils of Miocene age, which extend beyond the termination depths of the soundings at 30 m.

SummaryExperiments on winter wheat were made from 1980 to 1982 to test fungicide and aphicide sprays in factorial combination with four amounts of nitrogen fertilizer, applied in either one or two dressings in spring. The wheat was grown on three farms with contrasting calcareous clay soils from three soil series; each year it followed a 2-year break on one farm, a cereal rotation on the second and continuous wheat on the third. Soils were sampled to a depth of 0·9 m at seedling emergence in autumn, and again in February and April, to determine the NO3-N and NH4-N in each 0·3 m horizon. Crops were sampled for growth analysis at monthly intervals from March onwards and analysed for nitrogen content. Measurements of stem sap NO3-N concentration were also made at 2-weekly intervals from February or March to late June.Measurements of soil mineral N were used to calculate the fertilizer nitrogen dressings used in the experiments. The concentration of NO3-N in the stem sap was related to NO3-N in soil; concentiations remained high until most of the soil NO3-N had been removed by the crop. The time at which stem sap NO3-N concentration declined therefore acted as an index of soil N supply, and the data showed that fertilizer-N was needed when the NO3-N concentration fell below a 200 μg/ml threshold. Yields benefited from N applied in February or March only when stem sap NO3-N concentration fell below the threshold at this time.Apparent fertilizer nitrogen efficiency exceeded 70 % where yields were very large, but ranged between 53 and 64% where yields were smaller because either soil physical problems or disease restraints were present.A severe attack by take-all (Gaeumannomyces cerealis) caused premature senescence at one centre in 1980; this apparently prevented previously assimilated nitrogen from moving into the grain.

Zinc (Zn) deficiency is an important mineral nutrient problem that restricts the crop yield especially that of the cereals grown in calcareous soils. This study was carried out with the aim of testing the sensitivity of various cereal species consisting of bread (BDME-10, Bezostaja), durum (Kızıltan Ç-1252) and rye (Aslım) to Zn deficiency. In experiments carried out under greenhouse conditions plants were grown at two different Zn doses (Zn 0 and Zn 5 mg kg-1). When the plants were 44 days old, Zn deficiency symptoms were observed and scored for the severity of Zn deficiency according to 1-5 scale and the plants were harvested. With respect to the severity of Zn deficiency symptoms, the most severe symptoms were observed in the C-1252 (1.0) and Bezostaja (2.0) varieties while the least mild symptoms were observed in varieties of Aslım (4.0) and Kızıltan (3.0). A distinctive increase in shoot dry matter yield has been realized with Zn application which was highest in Ç-1252 (78.8%) and BDME-10 (52.5%) varieties. Greatly differential responses have been seen to Zn deficiency among cereal species and varieties within the same species. Symptomatically and with respect to dry matter yield while durum wheat was affected severely from Zn deficiency, bread wheat was affected moderately and rye has been seen to be affected least. According to the severity of Zn deficiency symptoms and plant growth cereals which are the subject of experiment have shown a rank as as Ç1252> BDME-10> Kızıltan> Bezostaya> Aslım.

In South Australia, Reseda lutea is abundant, invading pastures and crops on calcareous soils while in its native Mediterranean range it is uncommon in occurrence and is not reported as a weed of cultivated crops. Its invasive behaviour in South Australia may be attributed to vegetative growth of root fragments spread by cultivation, while propagation by seed is of minor importance. Surveys in Spain, Portugal, Morocco, France, Turkey and Israel indicated that agronomic differences, particularly depth of cultivation and seeding rates of cereals may explain why it is not a crop weed in these countries. Another difference is that plants in the region of origin have an associated fauna not present in Australia. These potential biological control agents include a root-boring weevil, Baris picicornis, flower- and seed-feeding urodontids, Bruchela suturalis and B. rufipes, and a leaf spot pathogen,Cercospora resedae. Baris picicornis was introduced from France and Turkey, under quarantine, to Australia but laboratory specificity-testing demonstrated that it could complete its life cycle on 2 commercially grown cultivars of Brassica rapa (choy sum and Chinese cabbage). Because of this, it is not proposed to release B. picicornis in Australia at present. Bruchela suturalis was also introduced into Australian quarantine from France but attempts to change its annual life cycle to Southern Hemisphere seasons were not successful, and a culture could not be established. Both Baris picicornis and Bruchela spp. remain promising agents, and further work on their introduction is justified by their potential for biological control of R. lutea.

Abstract The corrosion behavior of four uncoated low carbon steels: X52, X60, X65, and X70, and three non-ferrous metals: copper, bronze, and magnesium, buried in a real calcareous soil, after a year of exposure time was studied. Samples were not cathodically protected on gravimetric testing in field conditions. Severe roughness and color changes occurred in metals and surface evidenced the presence of rust and calcareous deposits. Oxide scale was generated when metals were immersed in calcareous soil for nine months. In field conditions, X52 was the most corrosion resistant and X65 the most susceptible to corrosion. At laboratory level, a real calcareous soil tested by electrochemical methods exhibited the same trend, which was ascribed to difference in microstructure and phase distribution in steels. Corrosion enhanced when X65 was exposed to calcareous soil collected in spring (0.031 mm/year) and rainy summer (0.077 mm/year), as rain enhanced ions mobility and corrosion. Non-ferrous coupons suggested that a passivation process occurred as corrosion rates (CRs) decreased (0.0025–0.0052 mm/year) compared with the results of low carbon steels.

The article presents the mechanical behaviour of calcareous waste under consolidated and drained condition in Triaxial compression test (CD). The host material currently being considered for the construction purpose of several buildings in Poland. One of the location of calcareous waste is in Łagiewniki area (in Cracow) [1,2]. In this work, particular attention has been paid to the to ensure fully saturation for all the tested soil samples and avoid generation of unwanted excess pore water pressure during shearing stage. The saturation level of soil samples was estimated based on Skempton’s law (B>0.95). CD Triaxial test have been conducted in order to derive information on its strength and stiffness properties.

Soil nutrient testing is an effective way to uncover soil nutrient status. However, the conventional testing method (CT method) and Mehlich 3 method (M3 method) demand long-time consumption, tedious testing steps, high testing cost, dangerous chemicals contained in extractant, etc. Therefore, it is important to develop a new rapid test method or improve the existing rapid test method of soil available nutrients. In this study, an improved Mehlich3 method (IM3 method) with the new combined extractant were developed and evaluated on the testing feasibility, precision, efficiency, and cost. The results showed that: (1) IM3 method avoided the usage of two hazardous chemicals, i.e., ammonium nitrate and nitric acid, which were difficult in purchase and storage but contained in the combined extractant of M3 method. (2) The correlation coefficients of available P, K, Fe, Mn, Cu and Zn in calcareous soil between M3 and CT, and between IM3 and CT methods all reached highly significant level. The correlation coefficient of available Zn between IM3 and CT method was significantly higher than that between M3 and CT method, and those of the other elements had not obviously changed. (3) The variation coefficients of available P, K, Fe and Cu determined by M3 and IM3 methods were all lower than those determined by CT method. The variation coefficients of available Mn and Zn determined by IM3 were 3.67% and 6.43%, which were slightly higher than those determined by CT method with 2.72% and 5.29%, but were lower than those determined by M3 method. (4) Under the premise of ensuring testing precision, IM3 method took only 6.3 min/piece for determining six elements, reducing testing time by 70.7% and 3.08% compared with CT (21.5 min/piece) and M3 (6.5 min/piece) methods, respectively. The testing cost of IM3 method was reduced by 26% and 61.2% compared with M3 and CT methods, respectively. In conclusion, IM3 method is an ideal rapid measurement method for the simultaneous determination of available soil nutrients in calcareous soil.

The results of a recent in situ testing program to establish standard penetration test – cone penetration test (SPT–CPT) correlation for the windblown calcareous desert sands of Kuwait are presented and analyzed. The program consisted of auger borings and static cone tests at five sites along a 35 km long corridor. The resulting correlation was employed for prediction of the allowable soil pressure of footings at seven sites in Kuwait where load tests were carried out on square concrete footings placed at a depth of 1 m below ground surface. A comparison of the measured to the predicted soil pressures using the Schmertmann method indicated very close agreement. The average ratio of measured to predicted soil pressure is 93% for the seven test sites. Recommendations are made for further testing to determine the long-term settlement components due to creep and cyclic loading. Key words: load tests, sands, footings, allowable pressure, settlement, field tests, borings, cone penetration tests.

AbstractThe construction industry in Abu Dhabi is thriving and its coastline has some of the most ambitious structures in the world. Whilst the subsurface evaporitic and calcareous soft rocks of this region are of great geological interest, they are relatively poorly understood from a geotechnical engineering perspective, forcing foundation designs to be overly conservative. Understanding the stiffness of the underlying geology at small strains is of great importance for the accurate estimation of ground movements around excavations and foundations, and yet routine post-SI laboratory testing programmes tend to focus on basic rock mechanics tests such as UCS tests. These procedures are generally unsuitable for use with calcareous rocks due to their friable and moisture sensitive nature, and rarely obtain parameters representative of actual in situ behaviour. The calcareous mudstone investigated in this paper has mechanical and structural characteristics falling between those of a soil and those typical of a rock and, as such, requires a geotechnical testing approach that combines methods from both soil and rock mechanics disciplines. The mineralogical, micro-structural and mechanical characteristics of this lithology have been examined via a suite of testing techniques, including XRPD, SEM, advanced triaxial with bender elements, along with industry standard procedures. Shearing, tensile and consolidation behaviours have been explored. Examination of the micro- and macro-scale features of this material shows it to be highly structured, with strength and stiffness being controlled by inter-granular bonding of Dolomite grains, as well as by mean effective stress state and rate of strain. The presence of fibrous Palygorskite acts to reduce the degree of bonding, causing specimens rich in this clay mineral to have a more ductile mechanical behaviour.

Soil testing helps the farmers to use fertilizers according to need of crops. Fertilizer use for targeted yield is an approach which take into account the crop need and nutrient present in the soil. A study on soil test crop response based integrated plant nutrient ion system (STCR) were conducted adopting targeted yield method in non-calcareous sandy loam soil of Ustifluvents at Mandan Bharti Agriculture College, Agwanpur, Saharsa during the two consecutive of 2018 and 2019. The experiment was laid out in RBD with nine treatments replicated thrice. The STCR approach with or without FYM at low, medium and high target yield markedly increase the yield and uptake of NPK of rice. Thus, the targeted yield model used to develop fertilizer precipitation equations provides a strong basis of soil fertility maintenance consistent with high productivity and efficient nutrient management for sustainable and enduring agriculture. This also improved the relationship between farmers and scientists and built confidence between them.

The field experiments were conducted for one season rabi 2008-09 at the Multilocation testing site Magura on calcareous soil to study the effect of integrated nutrient management on the growth and yield of onion (cv. BARI piaj 2). The experiment was laid out in a RCB design. There were five treatments involving four inorganic levels and organic levels another absolute control (no manure and no NPK). Higher level of inorganic T1 i.e., (120-45-85-40 kg ha-1 NPK S+ 5 t/ha CD) produced significantly higher bulb yield (18.76 t/ha) which was on par with T4 (17.87 t/ha) i.e., 5 t/ha poultry manure + remaining amount from inorganic fertilizer T2. The results also indicated that the same treatments recorded the highest single bulb weight, bulb yield as well as gross returns and MBCR (7.14) as compared to other treatments.DOI: http://dx.doi.org/10.3329/jesnr.v6i1.22059 J. Environ. Sci. & Natural Resources, 6(1): 159-162 2013

South and Southeast Kazakhstan underwent soil nitrogen forecasting and diagnosing for nutrition to establish the requirement of nitrogen fertilizers for field crops. The study established the possible use of alkaline hydrolyzable nitrogen as an indicator to provide field crops with available soil nitrogen. Managing the soil organic matter more accurately as the main source of nitrogen helps determine the spatial and temporal variability of its content in each specific field and to use a narrower (oriented to the prevailing soil types) scale of humus availability. The recent studies began in several stages, during 2014–2016, 2015–2017, and 2020–2021, on the irrigated light chestnut calcareous medium loamy non-saline and non-alkaline soil formed at the foothill loess plain of the Zailiyskiy Alatau, Kazakhstan. The nitrogen content of nitrates varied significantly over the years of research. In the control variants (without fertilizers), the recording of the minimum content of N-NO3 took place in 2016 compared with 2014 and 2015. In two consecutive years (2020–2021), 2,816 ha of arable land underwent testing in Almaty, Zhambyl, and Zhetysu regions, Kazakhstan. A total collection of 1,015 soil samples went through analysis, revealing a close correlation between the content of humus and alkaline hydrolyzable nitrogen in the upper soil layer of 0-30 cm. The hydrothermal conditions from a long multi-factorial field experiment data largely affected the intensity of mineralization and immobilization processes of the available nitrogen compounds. The rational use of nitrogen fertilizers makes it possible to increase the field crop yield with good quality and enhance the payback of applied fertilizers, maintaining and improving soil fertility.

Also, each treatment of the field results in a certain stress for the plants. The natural physiological processes within a plant are hindered influencing the growth of a plant. The objectives of the paper were to determine influence of retardant, herbicide and nitrogen on growth dynamics and the development o f vegetation stages in winter wheat. The field experiments were carried out during 1998 to 1999 in Research and Training Farm "Pēterlauki" on sod calcareous medium loam, pH k c l — 7.0, humus content 20 to 25 g kg 1 in soil. The research was carried out in the fields o f intensive type of winter wheat 'Otto' with the following treatments: control; control + herbicide; control + retardant; Ngo + 70 +40 + retardants. Herbicide Dialen (2,01 ha~’) and retardant Cikocel (1,5 l haT1 ) was applied during the final stage o f tillage, when testing parted nitrogen fertiliser, the first part (N go) was used after vegetation period was resumed. The second part (N70) was applied at the beginning of stalking stage (Zadoks Growth Stage 30). The third part (N40) - during shooting into ears. The grovAng dynamics was registered by aucsinographs (designed by I.Gronskis, M.Āboliņš). This equipment allows to observe and to register the intensity o f plant growth length within twenty-four hours. Registration tapes were changed every twenty-four hours. The analysis of the results showed that the most intensive plant growth happened in the morning (9:00 - 12:00 a.m.) and in the afternoon (3:00 - 6:00 p.m.). A decrease in the growing intensity was observed during night and midday. The data show how that the growth of winter wheat was seriously hindered even 2 weeks after the treatment with agro-chemicals. Winter wheat growing in length stops in the middle of flowering stage.

In 2018 and 2020, two winter durum wheat varieties, ‘Yakhont’ and ‘Yantarina’, were included in the State Register of Breeding Achievements for the North Caucasus region. They were developed at the Agricultural Research Center “Donskoy” by the intraspecific stepwise hybridization using both varieties and lines created in the ARC “Donskoy” and from the other regions. The purpose of the current study was to evaluate the new winter durum wheat varieties ‘Yakhont’ and ‘Yantarina’ according to productivity, resistance to abiotic and biotic stress factors, grain and pasta quality. The study was carried out in 2014–2020 in the ARC “Donskoy” located in the southern part of the Rostov region, which is favorable for winter durum wheat cultivation. The soil of the experimental plot – chernozem ordinary calcareous heavy loamy. The climate of the region is characterized by semi-arid hot summers and moderately mild winters. The sum of positive temperatures is more than 3400°С; Selyaninov hydrothermal coefficient (HTC) – 0.8; average annual air temperature – 9.7°С. The average annual precipitation is 450–600 mm. This paper presents the results of studying varieties according to the traits and properties mentioned above, points to their advantages compared to the standard variety ‘Donchanka’. On average, over seven years of competitive testing, the varieties ‘Yakhont’ and ‘Yantarina’ showed the following: productivity – 8.46 and 8.52 t/ha; 1000-grain weight – 40.8 and 43.5 g; drought tolerance – 4.5 points both; lodging resistance – 4.6 and 4.2 points; leaf rust resistance – 10–20% both. They excided the standard variety ‘Donchanka’ by 1.17 and 1.23 t/ha; 4.0 and 6.7 g; 0.5 points; 1.0 and 0.6 points; 3.0 %; 10%, respectively. The varieties ‘Yakhont’ and ‘Yantarina’ formed higher yields due to the increased number of productive stems per 1 m2 (591 and 542; the standard variety formed 498 productive stems), the productivity per head (1.52 and 1.68 g, the standard variety yielded 1.47 g). According to grain and pasta quality, ‘Yakhont’ and ‘Yantarina’ met not only the requirements of GOST R9353-2016 but also exceeded the standard variety ‘Donchanka’ in vitreousness (by 7.4 and 8.0%), grain nature (by 41 and 46 g/l), gluten content (by 2.0 and 0.70%), falling number (by 4 and 44 seconds), SDS-sedimentation (by 4 and 3 ml).

Triticum durum – is one of the most important food crops in the world that plays a fundamental role in combating hunger and improving global food security. Our research aimed to determine the influence of nitrogen fertilizers and preparations “Flora-S” and “Fitop-Flora-S” on the yield and grain quality of winter durum wheat. The studies and field trials were carried out on the experimental field of the Agrotechnology Academy (Academic Unit) of V. I. Vernadsky Crimean Federal University located in the low foothill zone of the Crimea (city of Simferopol). Soil – chernozem southern mycelial-calcareous low-humus developed on quaternary yellow-brown loess-like light clays. Field experiments were conducted in 2016–2018 according to B.A. Dospekhov methods of field research. The experimental design included the following options: Factor A – doses of nitrogen: N0+0 (control variant), N20+20, N40+40, N60+60; Factor B – foliar dressing of plants with preparations “Flora-S” and “Fitop-Flora-S” according to the manufacturer’s recommendations; Factor C: weather conditions of the year. The analysis of the sheaf material was carried out according to the methods of state variety testing of agricultural crops. Grain vitreousness was determined according to GOST (State Standard of the Russian Federation) 10987–76, protein content – GOST 10846-91, durum winter wheat grain class – GOST 9353-2016. The analysis of the experimental data shows that nitrogen fertilizers had a significant effect on the yield and grain quality of winter durum wheat variety ‘Amazonka’. Variant N60+60 was the most effective one; yield response to nitrogen fertilizer was expressed in the next quality parameters: yield – 4.65 t/ha (189.4 % more compared to control), protein content – 15.7 %, vitreousness – 85.1 %. The share of the influence of Factor B on such parameters as yield, protein content and vitreousness was 0.5, 1.8 and 0.8 %. The share of the influence of factor C on the same parameters was 6.9, 19.3 and 3.9 %. In the course of the research, we concluded that the most effective options of organic mineral preparations application were: “Flora-S” at the tillering stage of development + “Fitop-Flora-S” at the stage of head emergence; “Flora-S” at the tillering stage of development + “Fitop-Flora-S” at the stage of head emergence + “Flora-S” at the stage of milk development. These preparations contributed to yield improvement by 0.19 and 0.24 t/ha, respectively.

Among micronutrients, boron (B) occupies a prime place next to zinc (Zn) in Indian Agriculture. Acidic soils, coarse-textured soils subjected to leaching in high rainfall areas, and calcareous soils are likely to be deficient in B (Srivastava and Gupta 1996). According to an estimate based on soil testing of more than two lakh samples drawn from 508 districts of India indicated that 23.2 percent of soil samples are deficient in B (Shukla et al. 2019). Though there are several methods for the analysis of B in soils yet hot water-soluble B (Berger and Truog 1940; Gupta 1967) or dilute CaCl2 extractable B (Cartwright et al. 1983; Adams et al. 1991) are widely adopted for different soils all over the World (Diana 2008). The assembly adopted for the extraction of hot water soluble or dilute CaCl2 extractable B is costly as it requires the use of low B glass or quartz boiling flask equipped with a condenser tube for refluxing (Parker and Gardner 1981) which generally poses difficulty in handling and maintenance. Schuppli (1986) used a Teflon Erlenmeyer flask (125 ml) capacity attached to a Teflon reflux condenser to extract hot water-soluble B from soils, and an asbestos mat was placed between the hot plate and the flask to prevent damage to the Teflon flask. This publication proposes a low-cost assembly to extract hot water-soluble or hot CaCl2 extractable B in soils.

Tolerably mobile subsea foundations may be used to replace conventional fixed mudmat foundations for pipeline infrastructure and are designed to slide on the seabed along with the connected pipeline, in order to accommodate thermally induced horizontal forces. This allows the size of the foundation and the resulting fabrication and installation costs to be substantially reduced. The performance of mobile foundations is explored in this paper through four centrifuge model tests on a NC or LOC reconstituted calcareous silt obtained from the Northwest Shelf of Western Australia. The results are compared to three existing tests performed on a kaolin clay. The results show that under typical periodic surface sliding and intervening rests, sliding resistance evolves within a cycle with resistance peaks evident at either end of the sliding footprint due to the formation of berms, and the residual resistance increasing with sliding cycles towards a drained state. Shear and consolidation induced settlements accumulate with sliding cycles although at a reducing rate. The tests in the calcareous silt show higher normalised initial peak sliding resistance, a more dramatic loss and slower recovery of sliding resistance with cycles, and slower rate of decrease of incremental settlement compared with the response in kaolin clay.

Horizon Environmental Services, Inc. (Horizon) was selected by the City of Dripping Springs to conduct an intensive cultural resources inventory survey and assessment of the proposed Dripping Springs Wastewater System Improvements Project (EID 1) in Dripping Springs, Hays County, Texas (USACE Project No. SWF-2020-00075). This survey represents the first phase of a larger project involving the proposed construction of wastewater system improvements in Dripping Springs. The current phase of the project would involve three separate components—the West Interceptor segment, which extends approximately 3.7 kilometers (2.3 miles) in length along Onion Creek west of Farm-to-Market Road (FM) 12; the Reclaimed Water Line segment, which extends approximately 1.3 kilometers (0.8 mile) in length between Needham Road and the intersection of FM 12 and FM 150; an approximately 2.3-hectare (5.7-acre) effluent pond located south of an existing water reclamation facility south of FM 150; and the proposed expansion of the existing water reclamation facility adjacent to the proposed effluent pond, which together cover 3.3 hectares (8.0 acres). The linear rights-of-way (ROW) of proposed pipeline segments would measure a maximum of 30.5 meters (100.0 feet) in width, and the proposed project components would cover a combined area of approximately 18.5 hectares (45.6 acres). The proposed undertaking would be sponsored by the City of Dripping Springs, a public subdivision of the state of Texas. As a political subdivision of the state of Texas, the project would fall under the jurisdiction of the Antiquities Code of Texas (Natural Resources Code, Title 9, Chapter 191). In addition, the project would utilize funding provided by the Clean Water State Revolving Fund (CWSRF) program, which is a federal-state partnership between the US Environmental Protection Agency (US EPA) and the state of Texas. As the US EPA is a federal agency, the project would also fall under the jurisdiction of Section 106 of the National Historic Preservation Act (NHPA) of 1966, as amended. As the proposed project represents a publicly sponsored undertaking, the project sponsor is required to provide the Texas Historical Commission (THC), which serves as the State Historic Preservation Office (SHPO) for the state of Texas, with an opportunity to review and comment on the project’s potential to adversely affect historic properties listed on or considered eligible for listing on the National Register of Historic Places (NRHP) under the NHPA and for designation as State Antiquities Landmarks (SAL) under the Antiquities Code of Texas. From October 1 to 3, on November 4, and on November 22, 2019, Horizon archeologists Jesse Dalton, McKinzie Froese, Amy Goldstein, Elizabeth Sefton, and Jared Wiersema conducted an intensive cultural resources survey of the project area, including pedestrian walkover with shovel testing and backhoe trenching. The survey was performed under the supervision of Jeffrey D. Owens, who served as Principal Investigator, under Texas Antiquities Permit No. 9114. The purpose of the survey was to locate any significant cultural resources that potentially would be impacted by the proposed undertaking. Horizon’s archeologists traversed the project area on foot and thoroughly inspected the modern ground surface for aboriginal and historic-age cultural resources. Overall, vegetation across the entire project area generally consisted of short- to medium-length grasses interspersed with mature live oak and cedar trees, which afforded fair to good ground surface visibility (30 to 60%). Within the riparian zone of Onion Creek, vegetation consisted of tall, dense grass and mature honey mesquite, cedar, live oak, and hackberry trees, which provided poor ground surface visibility (<30%). The West Interceptor segment runs along the gravelly terraces of Onion Creek. Topographically, this segment of the project area consists of steep limestone steps and rocky outcrops that give way to flat, open fields. The proposed interceptor crosses Onion Creek at three locations, and the lower stream terraces of the creek have extensive gravel bars and debris associated with high-energy flooding. Soil profiles typically consist of a shallow A horizon of hard, calcareous clay loam underlain by dense gravelly deposits; however, in the southeastern portion of the West Interceptor, deeper clayey loam alluvium underlain by limestone bedrock was encountered. The Reclaimed Water Line segment traverses the west-facing hillslopes of upland ridges east of Onion Creek. Approximately the southeastern half of this segment of the project area would be constructed within the existing ROW of FM 12 west of the roadway, and construction, use, and ongoing maintenance of the roadway and associated facilities has resulted in extensive prior disturbances. Evidence of ground disturbance resulting from land clearing for housing developments and a transmission line were also noted within the northwestern portion of the proposed Reclaimed Water Line segment. The far northwestern end of the proposed Reclaimed Water Line segment skims the edge of the floodplain associated with a tributary of Onion Creek. Sediments on the terraces of this stream channel consist of calcareous loamy alluvial deposits, while soils across the upland portions of the segment consist of shallow deposits of gravelly clay and clay loam underlain by naturally degrading limestone bedrock. The water reclamation facility expansion and effluent pond segment are located on the upper terraces northeast of Onion Creek. The water reclamation facility is an existing industrial facility surrounded by septic fields, and prior disturbances from construction, use, and ongoing maintenance of the facility are extensive. The proposed expansion area to the north of the existing facility is currently utilized as a septic field. Sediments within this segment of the project area consist of shallow, gravelly, calcareous loamy to clayey loam alluvium underlain by naturally degrading limestone bedrock. In addition to a pedestrian walkover, the Texas State Minimum Archeological Survey Standards (TSMASS) require a minimum of 16 subsurface shovel tests per 1.6 kilometers (1.0 mile) for each 30.5-meter- (100.0-foot-) wide transect (or fraction thereof) for linear surveys unless field conditions warrant more shovel tests (e.g., in cultural high-probability areas) or fewer shovel tests (e.g., on steep slopes, in areas with excellent ground surface visibility). For block-area surveys, the TSMASS require two shovel tests per 0.4 hectare (1.0 acre) for project areas between 1.2 and 4.0 hectares (3.0 and 10.0 acres) in size. As such, a minimum of 37 shovel tests would be required within the West Interceptor segment, 13 shovel tests would be required within the Reclaimed Water Line segment, and 16 shovel tests would be required within the proposed water reclamation facility expansion and effluent pond area, for a total of 66 shovel tests for the project area as a whole. Horizon excavated a total of 106 shovel tests during the survey, including 82 shovel tests within the West Interceptor segment, 13 shovel tests within the Reclaimed Water Line segment, and 11 shovel tests within the facility expansion and effluent pond area. The shovel tests within the proposed facility expansion and effluent pond area were not all excavated directly within the final proposed construction footprint as the boundaries of this portion of the project area had not been firmly determined at the time of the survey, and no shovel tests were excavated within the existing water reclamation facility due to the extent of observable prior disturbances within this area. Overall, Horizon exceeded the minimum number of shovel tests required for the project area as a whole, and it is Horizon’s opinion that shovel testing was capable of fully penetrating sediments with the potential to contain subsurface archeological deposits (with the exception noted below where backhoe trenches were excavated along a portion of the West Interceptor segment). In addition to shovel testing, Horizon excavated four backhoe trenches within the southeastern portion of the proposed West Interceptor segment. The trenches were excavated at roughly 100.0-meter (328.0-foot) intervals along the proposed centerline to depths ranging from 105.0 to 350.0 centimeters (41.3 to 137.8 inches) below surface. Sediments observed within trench profiles typically consisted of moderately deep deposits of grayish-brown fine clay loam over yellowish-brown fine sandy loam. Dense deposits of river cobbles and/or naturally degrading limestone bedrock were observed at the base of three of the four trenches, and it is Horizon’s opinion that backhoe trenching was capable of fully penetrating sediments with the potential to contain archeological deposits. One chert flake was recorded in a shovel test (ST AG30) at a depth of 0.0 to 30.0 centimeters (0.0 to 11.8 inches) below surface at the far northwestern end of the West Interceptor project segment. Supplemental delineation shovel tests excavated around this initial discovery failed to produce any additional evidence of prehistoric cultural activity at this location, so the chert flake was recorded as an isolated artifact occurrence but was not documented as an archeological site. No other cultural resources of prehistoric or historic age were recorded within the project area during the pedestrian survey, shovel testing, or backhoe trenching. Based on the results of the survey-level investigations documented in this report, no cultural resources would be affected by the proposed undertaking. In accordance with 36 CFR 800.4, Horizon has made a reasonable and good-faith effort to identify historic properties within the project area. No cultural resources were identified within the project area that meet the criteria for designation as SALs according to 13 TAC 26 or for inclusion in the NRHP according to 36 CFR 60.4. Horizon recommends a finding of “no historic properties affected,” and no further archeological work is recommended in connection with the proposed undertaking. However, human burials, both prehistoric and historic, are protected under the Texas Health and Safety Code. In the event that any human remains or burial objects are inadvertently discovered at any point during construction, use, or ongoing maintenance in the project area, even in previously surveyed areas, all work should cease immediately in the vicinity of the inadvertent discovery, and the THC should be notified immediately. Following completion of the project, all project records will be prepared for permanent curation at the Texas Archeological Research Laboratory (TARL).

PT. X is one of the ice companies in which its largest company is located in Bali, more precisely in the Pidada area, North Denpasar. Based on field observations the area is an area that has a calcareous soil structure. The water source of PT. X was extracted from the groundwater. From the field observation, it was found that the pipeline network, that connected the inlet water to water treatment system and ice production units, was severely covered by faint white scale. In order to discover the origin of this scale, water quality testing need to be carried out. From the results, it was found that the total hardness in the inlet water, taken from the groundwater tap, was 162.85 mg/l with calcium concentration of 2.15 mg/l and iron 3.83 mg/l. Water quality testing was also carried out in the water treatment unit consisting of resin softener where the total hardness surprisingly increased into 279.81 mg/l, calcium concentration was 2.96 mg/l, iron concentration was 0.55 mg/l. Even after being treated in softener resin, the total hardness increased sharply to 483 mg/l, which categorized as extreme hardness. The increase in total hardness indicates that there was a failure in the operation of the water treatment system, even it also contributed to the higher hardness and calcium concentration. This over-year’s treatment failure has been causing accumulation of hardness and calcium concentration in the compartment of both water treatment system and ice production unit that inflicts a higher hardness level in the effluent.