Coşkun Gülser

Using tea waste as a new casing material in mushroom (Agaricus bisporus (L.) Sing.) cultivation.

In this study, the possibility of using tea production waste as a new casing material in mushroom (Agaricus bisporus) cultivation was investigated. Some physical and chemical characteristics of tea waste, fermented tea waste and a mixture of tea waste with peat were compared with that of peat casing, as were their effects on yield. The highest yield was obtained from peat casing. Using tea production waste alone as a casing was not acceptable for assured yield when it was compared with peat. But, a mixture of tea production waste with peat in 1:1 (v:v) ratio increased the yield. There was no significant difference between the mushroom yields of tea production waste+peat and peat casing materials at the end of 30 and 40 days. High salt content, organic and inorganic compounds in casing materials caused reduction of yields. However, a high iron content in casing material gave a significant positive correlation with total yield at 40 days.

Effects of Different Agricultural Wastes on Some Soil Quality Indexes in Clay and Loamy Sand Fields

Effects of manure (M), hazelnut husks (HH), tea waste (TEW), and tobacco wastes (TOW) on some soil quality indexes were monitored for more than 2 years in a clay field and a loamy sand field. While soil organic carbon (OC) contents were around 2% after 30 months in clay, they were generally less than 2% after 7 months in loamy sand. Organic wastes generally increased aggregate stability (AS) and field capacity and decreased bulk density (BD) of the soils. Soil pH decreased with TEW and increased with M treatment. Tobacco wastes exerted the greatest effect on AS, EC, and nitrate (NO3) nitrogen (N). Hazelnut husks and TEW had the greatest effect on soil respiration in clay and loamy sand soils, respectively. While BD and pH increased, the other indicators generally decreased between the first and the last sampling. Soil quality can be improved in coarse-textured soils using TEW and HH and in fine-textured soils using TEW and M.

Influencing Factors and Prediction of Hydraulic Conductivity in Fine-Textured Alkaline Soils

Hydraulic conductivity is an essential parameter in hydrological cycle studies. Determination of saturated hydraulic conductivity (Ks) in fine-textured, especially alkaline, soils is a difficult process and takes time. In this study, the effects of some soil properties on Ks in fine-textured alkaline soils were determined, and Ks values were predicted using pedotransfer (PTF) models. Ks, which varied between 0.011 and 0.625 cm h−1 in 64 different soil samples, significantly decreased with increasing exchangeable Na percentage (ESP), sodium absorption ratio(SAR), exchangeable Na (exch. Na), and clay content of soils. The correlation coefficients were divided into a series of direct and indirect effects of the soil properties on Ks by path coefficients. The direct effects of selected properties on Ks were in the following order; exch. Na (42.6%) > ESP (37.0%) > clay (21.3%) > CEC (16.8%) > SAR (9.7%) > pH (8.4%) > silt (6.4%) > electrical conductivity (EC) (0.8%). The highest indirect effect on Ks was obtained with EC (43.0%) mediated by exch. Na. Accuracy and reliability of PTFs were assessed with the average of root mean square error (RMSE) and R2 values in the training and testing data sets, respectively. Using clay and silt fractions together with EC, exch. Na, ESP, or SAR in the second order equations significantly increased the accuracy and reliability of PTFs. Exchangeable Na was one of the most important soil properties that affected Ks directly in these soils. Using soil chemical properties in PTFs with soil physical properties showed that saturated Ks values can be predicted more accurately in fine-textured alkaline soils.

Effects of agricultural wastes on the hydraulic properties of a loamy sand cropland in Turkey

Abstract This study was carried out to determine the proper amount of application for manure (M), hazelnut husk (Corylus avellane L.) (HH), tobacco (Nicotiana tabacum L.) (TO) and tea (Camellia Sinensis (L.)) (TE) wastes based on hydraulic property improvement of a loamy sand cropland in Turkey. The effects of agricultural wastes on field capacity (FC), permanent wilting point (PWP), available water content (AWC), relative saturation (RS) and initial infiltration rate (IR) were determined for a loamy sand soil 7 months after agricultural wastes were incorporated to 15 cm soil depth at four different rates (0, 2%, 4% and 6%, weight:weight) in a randomized plot design experiment with three replicates. While increases in soil OM content for the M application rates were generally lower, TE and HH treatments including high organic carbon (OC) contents resulted in high soil organic matter (OM) increases. Organic wastes generally increased the values of soil hydraulic properties, with increased aggregate stability (AS) and total porosity (F) and reduced bulk density (BD). The highest AS and F values were obtained with 6% HH and 6% TE applications, respectively. Due to different mineralization rates of the organic wastes attributable to their carbon: nitrogen (C:N) ratios, the same application rate had different effects on the soil’s hydraulic properties. Manure, having the lowest C:N ratio, generally had a lower effect on AS and BD. Increased IR due to increases in AS and F by the agricultural waste treatment, especially at 4 and 6% HH, reduced the AW content to 15 cm compared with 2% HH. This indicates that the significant application of higher C:N ratio wastes is not suitable in terms of AW, due to significant improvement of IR. While the highest FC (17.3%) and AWC (10.7%) values were found in the 6% TE application, the highest PWP (7.2%) and IR (333.4 cm h−1) were in the 6% TO and 6% HH applications, respectively. To improve soil physical and hydraulic properties, 6% TO and M, 4% TE and 2% HH applications are suggested for loamy sand cropland.

Changes in Soil Quality by Compost and Hazelnut Husk Applications in a Hazelnut Orchard

ABSTRACT In this study, changes in some soil quality indexes in a hazelnut orchard located in the Black Sea Region of Turkey were investigated after 6 months of compost (CMP) and hazelnut husk (HH) applications. CMP and HH applications increased soil organic carbon (OC) content from 1.40% to 2.57 and 3.51%, and electrical conductivity from 0.06 dS m−1 to 0.20 and 0.91 dS m−1, respectively (P < 0.01). In comparison to control treatment, CMP and HH applications increased the sum of exchangeable cations by 31 and 37%, aggregate stability by 2 and 7%, initial infiltration rate by 34 and 436%, and reduced bulk density by 20 and 33%, penetration resistance by 33 and 67%, respectively (P < 0.01). Physical and chemical soil quality parameters were improved using both HH and CMP in the hazelnut orchard. Although both organic matter sources were effective on quality of clay soil, slow mineralization rate of HH in soil due to including the highest C:N ratio (55%) caused greater effects of HH on soil quality indexes than that of CMP (having 22% C:N ratio) after 6 months of application.

Erratum to: Chemical contamination in upper horizon of Haplic Chernozem as a transformation factor of its physicochemical properties

Purpose The effect of Cu, Zn, and Pb high rates on the physical properties and organic matter of Haplic Chernozem (Clayic) (A1 horizon 0–20 cm) under model experimental conditions was studied.

Clay activity index as an indicator of soil erodibility

Received : 04.01.2017 Accepted : 02.04.2017 Activity index (AI) value characterizes the relationship between the plasticity index and clay content. In this study, AI value was investigated to determine whether it might be used as an indicator of soil structural stability or not. The AI values of 75 soil samples gave the significant negative correlations with their dispersion ratio (DR), soil erodibility factors (K) and erosion ratios (ER). Also, the AI values of the soils including clay and sandy clay loam textural class showed significant positive correlation with soil structural stability index (SSI). It seems that the AI value may be used as an indicator of soil structural stability.

Toprağın ısısal yayınımının fonksiyonel değişimi ve toprak sıcaklığına etkisi

Toprak sicakliginin izlenmesinde isisal yayinim onemli bir parametredir. Bu calismada, isisal yayinim katsayisinin deneysel ve fonksiyonel iliskilere gore elde edilen degerlerine bagli olarak derinlik boyunca toprak sicakliklari belirlenmis ve karsilastirilmistir. Samsun Ili Bafra Meteoroloji Istasyonunun Mayis-Temmuz 2012 aylarindaki ortalama gunluk toprak sicaklik degerleri icin 5-10; 10-20; 20-50; 50-100 cm toprak katmanlarinin ortalama isisal yayinim katsayilari 3.65·10-6; 7.27·10-6; 12.82·10-6; 16.68·10-6 m2 sn-1 olarak hesaplanmistir. Isisal yayinim ile toprak derinligi arasindaki iliski dogrusal, eksponansiyel, ustel ve parabolik fonksiyonlar ile ifade edilmistir. Isisal yayinima ait deneysel (meteorolojik) veriler ile fonksiyonlardan hesaplanan degerler arasindaki ortalama nispi hatalar %7.79 ve %18.64 arasinda degistigi ve parabolik fonksiyonla yapilan hesaplamada nispi hatanin en dusuk oldugu bulunmustur. Fonksiyonlara bagli olarak bulunan isisal yayinim katsayilarina gore hesaplanan sicaklik degerleri ile deneysel sicaklik degerleri arasindaki nispi hatalar ise %2.50 ve %2.83 arasinda degisim gostermistir. Parabolik fonksiyon ile belirlenen isisal yayinim katsayisinin kullanilmasiyla hesaplanan toprak sicaklik degerleri en dusuk nispi hatayi vermistir.

ANALYTICAL INVESTIGATION OF SOIL DEFORMATION AND STRAIN ACCORDING TO RHEOLOGY EQUATION

Relaxation processes of soils are related with deformation and strain properties of soils. Deformation and strain status of soils affect agricultural practices significantly. In this study, soil deformation and strain was investigated theoretically according to basic rheology equation. In case of harmonic and linear variability of initial deformation which causes relaxation process in soil, soil strain was determined using solution of basic rheology equation with respect to time. Relationships for soil deformation were obtained in harmonic and linear variability conditions of initial strain causing shear process. Time dependent soil deformation occurred with external load, changes linearly with soil physical properties such as moisture, bulk density, and linear and angular deformation velocities of agricultural machinery and equipments.