Effect of freezing and thawing processes on some physical properties of saline–sodic soils mixed with sewage sludge or fly ash

Dispersion of saline–sodic soils was rather difficult to leach. Therefore, negative effects of freeze–thaw on soil physical properties should be reduced by inexpensive and practical methods. This study investigates the effect of freeze–thaw cycles (3, 6, and 9) on wet aggregate stability, bulk density, and permeability coefficient in three soils with different electrical conductivity and exchangeable sodium percentage levels (soil I: 5.30 dS m⁻¹, 47.51%; soil II: 42.80 dS m⁻¹, 55.45%; soil III: 36.30 dS m⁻¹, 59.34%) which consist of different proportions of sewage sludge and fly ash by volume (10%, 20%, and 30%). The experiment was conducted under laboratory conditions using disturbed and non-cropped soil samples mixed with sewage sludge and fly ash. Soils mixed with sewage sludge produced higher aggregate stability and permeability coefficients and lower bulk density values as compared to the soils mixed with fly ash. Sewage sludge added with a rate of 30% eliminated the negative effects of freeze–thaw processes on wet aggregate stability. Freeze–thaw processes did not affect the bulk density of the soils II and III, which were mixed with sewage sludge. However, fly ash addition decreased the bulk density of these soils very significantly after nine freeze–thaw cycles. Addition of sewage sludge or fly ash with rates of 20% and 30% significantly increased the permeability coefficients in soil I after nine freeze–thaw cycles. Results indicated that addition of sewage sludge and/or fly ash to saline–sodic soils could be alternative way for reducing negative effects of freezing–thawing on soil wet aggregate stability, bulk density, and permeability coefficient.     

The use of iron (III) ferrocyanide soil amendment for removing salt from the soil surface

Accelerated soil salinization is a worldwide concern. Our study was carried out to determine the effects of different rates (0, 5, 10, and 15?mmol kg^?1) of iron (III) ferrocyanide application to remove salts from the soil. Within two weeks of its application, iron (III) ferrocyanide at 5, 10, and 15?mmol?kg^?1 removed 12.2%, 26.5%, and 42.9% of the total salts from the soil, respectively. Results suggested that iron (III) ferrocyanide application at 15?mmol?kg^?1 is one of the most rapid and effective ways to remove substantial amounts of salts from undrained soil (land) where fresh water is scarce.     

Effects of diatomite on soil physical properties

Organic and inorganic soil amendments are commonly added to soil for improving its physical and chemical characteristics which promote plant growth. Although many inorganic amendments are extensively used for this purpose, diatomite (DE) is not commonly used. This study was conducted to determine effects of diatomite applications (10, 20, and 30% v/v) on physical characteristics of soils with different textures (Sandy Loam, Loam, and Clay), under laboratory conditions. The results indicated that diatomite application protects large aggregate (> 6.4 mm) formation in clay-textured soils, however it reduced the mean weight diameter in sand-textured soil. 30% diatomite reduced mean weight diameter in sand-textured soils from 1.74 to 1.49 mm. Diatomite applications significantly increased aggregate stability of all the experimental soils in all aggregate size fractions. In overall, aggregate stability increased from 28.04% to 45.70% with the application rate of 30%. Diatomite application also significantly increased soil moisture content at field capacity in SL textured soil. 30% diatomite increased field capacity in sand-textured soil in the percent of 43.78 as compared with control. Therefore it is suggested that diatomite may be considered as a soil amendment agent for improving soil physical characteristics. However, its effectiveness in enhancing soil properties depends on initial soil factors and texture. Moreover, since its protective effect against large aggregate (> 6.4 mm) formation and reducing effect on soil penetration resistance in clay textured soils, diatomite might be an alternative soil amendment agent in soil tillage practices and seedling.     

Fruit Characteristics and Detachment Parameters of Sour Cherry (Prunus cerasus L. cv. ‘Kütahya’) as Affected by Various Maturity Stages

The variability in fruit maturity and quality has difficulties in determining the optimal harvesting maturity. Therefore, maturity stage in harvest is crucial for both fruit quality and minimizing the fruit detachment force. This study investigates the fruit characteristics and detachment parameters of sour cherry (cv. ‘Kütahya’) in terms of different maturity stages. Sour cherries were grouped into five different maturity stages by observation according to their color and dimensions. The fruit mass and dimension increased as a function of maturity stage; however, the fruit mass remained almost same after the 4th stage. The highest values of total soluble solids and titrable acid contents of sour cherry were gained in the last stage of maturity. The value of chroma of fruit outer color was higher 50?% than that of fruit inner color in the 1st maturity stage. However, it was almost same in the 5th stage of maturity. Increasing fruit maturity caused a decrease in the values of fruit detachment force ranging from 4.25 to 1.78 N, giving the coefficient of determination of 0.947. Similarly, the ratio of fruit detachment force to fruit mass, detachment stress, and specific energy decreased as the fruit maturity increased. The harvest of sour cherry is done only once in the optimum time to decrease the harvest cost. Minimizing the variability in fruit maturity throughout the tree is essential for gaining the maximum profit and lower fruit detachment force in this convenient time. Results of this study indicated that 3rd?5th maturity stages were critical for harvest. In order to attain the maximum poundage per tree and color for the market the most of the fruits should be in these stages. Therefore, appropriate management strategies that could homogenize the maturity throughout the tree should be applied.     

Mineral Nutrient Acquisition by Cotton Cultivars Grown under Salt Stress

Physiological responses were investigated in two cotton cultivars grown at various concentrations of sodium chloride (NaCl) in order to determine the degree of the tolerance of the cultivars to salt stress and understand the physiological responses with respect to utilization of mineral nutrients. After germination of the seeds of cotton cultivars, they were transferred into standard pots with 210 g sterilized compost and watered with 30 ml Hoagland’s solution containing different concentrations (0, 50, 100, 200, and 400 mM) of NaCl at two-day intervals for 3 months. Growth parameters were measured and the mineral nutrient analyses were done using inductively coupled plasma optical emission spectrometry (ICP-OES, Thermo Fisher Scientific, Waltman, MA). It was observed that plant growth and mineral nutritional status of both cultivars were altered extensively in those grown with NaCl. Excess NaCl reduces the concentrations of certain mineral nutrients and increases that of others, the patterns depending on the mineral nutrient and the plant part and varieties being compared to the control.     

Effects of Sewage Sludge Amendment on Some Soil Properties,Growth, Yield and Nutrient Content of Raspberry (<Emphasis Type="Italic">Rubus idaeus</Emphasis> L.)

This study was focused not only at the assessment of effects of different sewage sludge application rates on vegetative parameters and yield of raspberry (Rubus ideaus L.) but also heavy metal accumulation in the soil and raspberry leaves. A three-year field study was set up in a completely randomized block design with five sewage sludge application rates (0.0, 2.5, 5.0, 7.5 and 10.0?kg of dry matter per plant) and three replications. One-year-old, virus free ‘Heritage’ saplings were used for the experiment. The results of this study clearly indicated that the sewage sludge application is an effective mean for improvement of vegetative growth, yield, soil and plant chemical properties of raspberry in light textured soils. In addition to macro-element contents, sewage sludge application also caused significant changes in micro-element content of soils. No adverse effects of these increases were observed on plants throughout the experimental period. The most effective application rate was found as 7.5?kg per plant for this ecological condition. It can be concluded that when properly treated and applied to farmland sewage sludge is not only disposed economically but also improved vegetative growth and yield of raspberry.     

Effects of wastewater irrigation on soil and cabbage‐plant (brassica olerecea var. capitate cv. yalova‐1) chemical properties

The use of wastewater for irrigation is increasingly being considered as a technical solution to minimize soil degradation and to restore nutrient contents of soils. The aim of this study is to increase fertility and minimize degradation of soils irrigated with wastewater exposed to different purification treatments. A field experiment was conducted to investigate the effects of control and irrigation with wastewater, which had undergone different purification treatments, on macro‐ and micronutrient distribution within the soil profile and nutrient contents of cabbage (Brassica olerecea var. Capitate cv. Yalova‐1) in Erzurum, Turkey. Wastewater irrigation and preliminary treatment–wastewater irrigation significantly affected soil chemical properties especially at 0–30 cm soil depth and plant nutrient contents after one year. Application of wastewater increased soil salinity, organic matter, exchangeable Na, K, Ca, Mg, plant‐available P, and micro‐elements and decreased soil pH. Wastewater increased also yield and N, P, K, Fe, Mn, Zn, Cu, B, and Mo contents of cabbage plants. Undesirable side effects were not observed in plant heavy‐metal contents, due to salinity and toxic concentrations of metals from the application of wastewater to soil.     

Determination of the Tissue Distribution of PPO on Caramote Prawn (Melicertus kerathurus,Forskal, 1755) and Jinga Shrimp (Metapenaeus affinis,H. Milne Edwards, 1837) Caught from Izmir

Tissue distribution of polyphenol oxidase (PPO) was studied in caramote prawn (Melicertus kerathurus) and jinga shrimp (Metapenaeus affinis) postmortem. Activity was analyzed in different tissues: the head (cephalothorax + carapace), carapace, exoskeleton of the abdomen, pereopods, and maxillipeds, individually. Based on the results, PPO activity of jinga shrimp was determined to be higher than caramote prawn during the research period. Partial tissue distribution showed that the highest activity was determined in carapace by using 70% ammonium sulfate fractions. Partial tissue distribution was also used to determine the spread of black spots. In addition, comparison between the PPO levels of caramote prawn and jinga shrimp was performed. The importance of these species is their economic value. However, there is no available data in the literature about caramote prawn and jinga shrimp. The determined data showed us that using antioxidant chemicals would be suitable for jinga shrimp.     

Effects of Vermicompost Application on Soil Aggregation and Certain Physical Properties

Application of organic waste on agricultural land as a soil conditioner and fertilizing material has lately gained much attention. This study was conducted to determine the effects of vermicompost applications (0·5%, 1%, 2% and 4% w/w) on physical characteristics of soils with different textures (sandy loam, loam and clay), under laboratory conditions. The results indicated that in the higher soil aggregate fraction (>12·7 mm) aggregate fraction was limited at the three soils. Vermicompost applications in all three soils significantly increased organic matter content. When compared with control, the increasing rates in organic matter content were 14·0%, 23·8%, 42·0% and 90·2% for 0·5%, 1%, 2% and 4% vermicompost application doses, respectively. Vermicompost applications increased the wet aggregate stability and decreased the dispersion ratio of all the experimental soils in all aggregate size fractions. Overall, wet aggregate stability increased from 26·9% to 52·2% with the application rate of 4%. Correlation coefficient between organic matter content and wet aggregate stability was found as 0·918^**. The lowest mean bulk density and the highest mean total porosity occurred when the most vermicompost was added. In all the soils studied, the highest permeability coefficients were gained with the application dose of 2%. As a result of increase in wet aggregate stability and decrease in bulk density, air permeability increased, and penetration resistance decreased significantly. The results obtained in this study have clearly indicated that the vermicompost application is an effective way to improve soil physical characteristics. Copyright © 2015 John Wiley & Sons, Ltd.