Climate is a major influence on weathering processes affecting soil parent materials. Important contributors to soil formation in arid and semi-arid climatic zones are the diurnal cycles of solar heating and cooling that cause mechanical or physical disintegration of rock or parent materials, and wind-blown sands that score and abrade exposed rock surfaces. By using the Soil Taxonomy classification system, the initial aim of this study was to carry out a pedological evaluation for four soil profiles, classified as Xeric Haplocalcid and Xeric Haplocambid, formed on different parent materials (limestone, marl and old alluvial deposits) under the same conditions, including topography and vegetation, in a semiarid region. The second stage was the exploration of the similarities and differences in the classifications resulting from either the pedogenic processes, or from other factors, by determining the degree of soil weathering using geochemical data. To achieve this, soil samples were collected from the horizons to investigate their mineralogical, geochemical and physiochemical properties. The study also considered other features, such as the pedogenic evolution of soils, through the use of weathering indices, namely the Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), Base/R2O3 Ratio, Weathering Index of Parker (WIP) and Plagioclase Index of Alteration (PIA). The results clearly showed that soil development at the Altınova State Farm at Konya in the Central Anatolia region of Turkey is due to slow pr ogressive weathering. For this case, the main indicators are secondary calcium carbonate illuviation and weak structural development with a weathering ratio of silicon to aluminium greater than two in all profiles.
Abstract. The purpose of this research is to assess the geochemical mass-balance and weathering intensity of Typic Haplustert and Lithic Ustorthent soils represented by four profiles that developed in a Quaternary-age basaltic toposequence under semi-humid conditions in the central Black Sea region of Turkey. The researchers employed mass-balance analysis with a view to measuring elemental gains and losses along with alterations concerning the soils formed on the basaltic parent material. For this end, geochemical properties, elemental mass-balance changes and certain physicochemical features were identified to benchmark the weathering levels of the profiles. Lithic Ustorthents are distinguished by having a rough texture along with a low organic substance ingredient, whereas Typic Haplusterts have a high clay texture with low bulk density and slickenside features. X-ray diffraction showed that smectites were the prevailing minerals inside the Typic Haplusterts, while a significant amount of kaolinite and illite was observed in the Lithic Ustorthents. Mass-balance computations indicated that massive mineral weathering resulted in substantial Si losses through leaching as well as an exchange of cations, such as Na+, K+, Ca2+ and Mg2+, particularly from the upper horizons. The study also took into account other features such as the pedogenic evolution of soils using weathering indices such as CIA, CIW, bases/R2O3, WIP, P and PIA. According to the results, CIA, CIW, PIA, P, WIP and bases/R2O3 index values of all soils varied between 42.33 to 73.83, 44.46 to 80.43, 37.53 to 65.63, 75.39 to 84.31 and 0.45 to 1.27 respectively, to solum depth. This result indicated that soils classified as Entisol and Vertisol have similar pedochemical properties. In spite of similar weathering rates, the soils were classified under different groups as a result of erosion. This showed that the conditions for soil development in the studied area had a far more impact on weathering and elemental loss than the parent material on the site.
Understanding of soil forming factors is crucial to define physical, mineralogical and morphological properties of soils. In addition to that soil formations were highly associated with slope positions which have influence on pedogenetic and weathering process of the soils. Because, topography or relief affects how water and other material are added to and removed from soils. The aim of this study is to enhance our understanding of the role toposequence in controlling chemical weathering, influence on physical and mineralogical properties in soils developed on basaltic parent material under sub-humid terrestrial ecosystem in Black Sea region of Turkey using geochemical and mineralogical data obtained from X-ray diffraction and Scanning Electron Microscope analysis. For this purpose, four representative profiles formed on different topographic positions of transect were investigated and designated according to Soil Survey Staff (2014)/IUSS Working Group WRB (2015) classification systems. The results clearly showed that topography strongly affects soil physical, mineralogical and morphological characteristics either directly or indirectly in the local region even soils formed on the same parent material with the same climatic condition. This case was also explained with chemical weathering indices (Chemical Index of Alteration and Chemical Index of Weathering) in this study.
Toprak neminin konumsal ve zamansal olarak dağılımı, kurak ve yarı kurak bölgelerde kuraklık izlemesi, ürün sulama planlaması, ürün tahmini gibi havza seviyesindeki tarımsal uygulamalarda anahtar bir parametredir. Ayrıca, radar uydu görüntüleri çeşitli bölgeler için toprak ve bitki örtüsü dağılımının mekânsal ve zamansal olarak ortaya konulmasını sağlamak için kullanılmaktadır. Aktif mikrodalga sensör sistemleri kullanarak yüzey toprağı neminin tahmini araştırmacılar, koruma planlamacıları ve doğal kaynakların sürdürülebilir kullanımını izleyen karar vericiler için yararlı bilgilerden biridir. Bu çalışma, yarı kurak iklime sahip Altınova Tarım İşletmesi arazisinde seçilen altmış dört kilometrekarelik test alanı topraklarında yürütülmüştür. Dört farklı zamanda elde edilen Sentetik Açıklıklı Radar (SAR) görüntülerinin gerisaçılım değerleri (Radarsat-2) ve yüzey toprağı nemi arasındaki ilişki belirlenmeye çalışılmıştır. Bu amaçla, Altınova Tarım İşletmesine ait dört SAR görüntüsü (4 tane Radarsat-2 görüntüsü) kullanılmıştır. Eş zamanlı olarak, 730 farklı noktada 250 m aralıklarla yüzey toprak örnekleri 0-20 cm'den alınmış ve çalışma alanı boyunca gravimetrik yöntem kullanılarak yüzey toprağının nemi belirlenmiştir. Her örnekleme periyodu için yüzey toprağı nem dağılım haritaları ordinary kriging kullanılarak üretilmiştir. Toprak nem dağılım haritalarına göre Ağustos verileri, çalışma alanı boyunca diğer örnekleme dönemlerine kıyasla yüzey toprağı neminde en fazla değişiklikleri göstermiştir. Bu nedenle çalışma alanı boyunca gerisaçılma (Ağustos 2012 Radarsat-2 verilerinden elde edilen) ile toprak nemi içeriği arasındaki ilişkinin diğer SAR veri sonuçlarından daha iyi olduğu bulunmuştur (r=0.506, p<0.05). Estimation of soil moisture by synthetic aparture radar (microwave) images in semi arid regions
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