Soil management practices can have negative or positive effects on soil quality. Our objective was to assess the effect of long-term agricultural practices by evaluating selected soil physical and chemical properties. Soil samples were collected from two depths (0 to 15 and 15 to 30 cm) within a native pasture and an adjacent agricultural field that was being used for three different crop rotations. Soil quality was quantified using aggregate stability, bulk density, soil texture and available water content as physical properties and pH, electrical conductivity, organic matter and available phosphorus as chemical properties. The farmland soils were functioning at 71 and 70 per cent of their full potential at the 0-to 15-and 15 to 30-cm-depth increments, respectively, whereas those from the pasture were functioning at 73 and 69 per cent, respectively. The assessment showed substantial loss in soil organic carbon following 50 years of farmland cultivation. Tillage and fertilizer applications were presumably the primary reasons for weaker spatial dependence within farmland at the 0-to 15-cm depth. Grazing was postulated as the main reason for weaker spatial dependence within the pasture soils at the 15-to 30-cm depth. Overall, we conclude that 50 years of cultivation has not caused soil quality to decline to a point that threatens sustainability of the agricultural fields.Notes: CV, coefficient of variation; ns, not significant; TOC, total organic carbon; BD, bulk density; EC, electrical conductivity; SQI, soil quality index. a Significant at the 0·01 level. b Significant at the 0·05 level.

No abstract

Phosphorus (P) is essential to all known life forms because it is a key element in many physiological and biochemical processes. In this study, different physiographic units of Atabey Plain have developed soils with varying characteristics. The variability in land use and fertilizer input management causes changes in the availability and geochemical fractions of phosphorus. In this study, 29 surface soil samples (0-20 cm) were taken from various fruit orchards to investigate the plant cover-related inter-fraction mobility and availability of P as a function of soil characteristics. Sequentially extracted geochemical P fractions were: sodium bicarbonate [NaHCO3-P (organic Po, inorganic Pi, and Total Pt)], sodium hydroxide [NaOH-P (Po, Pi, and Pt)], citrate bicarbonate dithionite (CBD-P), hydrochloric acid (Ca-P), and residual (Res-P) phosphorus. In order to study the relationship of phosphorus fractions with soil properties, chemometric analyses were performed. According to the results, the average concentrations of the fractions in descending order were: Ca-P (200-1029 mg kg-1) > Res-P (55.3-449 mg kg-1 ) > CBD-P (56.5-204 mg kg-1) > NaOH-Pi (26.0-206 mg kg-1) > NaHCO3-Pi (4.38-93.4 mg kg-1) > NaOH-Po (0.55-30.0 mg kg-1) > NaHCO3-Po (0.26-7.56 mg kg-1). The added fertilizer P was likely to be converted to NaOH-P in the short term and Ca-P and/or CBD-P for a relatively longer time. It was determined that the fractal distribution of these fractions varied according to the land use pattern and soil properties such as texture, organic matter, carbonates, and iron and manganese oxide minerals.

ÖzBir bölgede çayır ve mera alanları ile ilgili uygun ıslah ve yönetim çalışmalarının uygulanabilmesi için, öncelikle mevcut vejetasyonların tür bileşiminin tespit edilmesi gerekmektedir. Iğdır ovasının tuz etkisine maruz kalan taban arazilerinin büyük bir kısmında tarla tarımı yapılamamakta ve otlatılarak ya da biçilerek değerlendirilmektedir. Bu çalışma daha önce bitki örtüsü hakkında hiç çalışma yapılmamış, toprak tuzluluğundan farklı düzeyde etkilenmiş doğal kurak taban çayır kesimlerinin tür bileşimini ve aralarındaki farklılıkları tespit etmek ve sonrasında yapılacak çalışmalara altlık oluşturmak amacıyla yürütülmüştür. Çalışmada 2012 ve 2013 yıllarında dört çayır kesiminde tuzlu (EC = 4.82 dS/m, DSY = %11.6), alkali (EC = 1.48 dS/m, DSY = %39.1), tuzlu-alkali (EC= 4.31 dS/m, DSY = %39.7) ve tuzluluk problemi olmayan (EC = 0.4 dS/m, DSY = %4.3) çayır kesimlerinde hâkim türlerin çiçeklenme dönemi sonunda Quadrat yöntemi (0.5 x 0.5=0.25 m 2 ) kullanılarak vejetasyon ölçümleri yapılmıştır. Buna göre tuzluluk problemi olmayan çayır kesiminde 39, tuzluluk sorunu olan çayır kesiminde 41, alkalilik sorunu olan çayır kesiminde 38 ve tuzluluk ve alkalilik sorunu olan çayır kesiminde 26 tür tespit edilmiştir. Çalışma sonucunda çayır kesimlerinin tür bileşimlerinin özellikle familya bazında farklılık gösterdiği, normal koşullara göre tuz etkisinde kalmış çayır kesimlerinde baklagil tür sayısının daha az olduğu ve hayvanlar tarafından daha az tercih edilen tür sayının artığı belirlenmiştir.

Soil formation processes and cropping and management practices affect plant-available amounts of boron (B) in soils. Using Pearson's correlation and principal component analyses, this study investigated the relationships between soil properties and plant-available boron concentrations in 69 soil samples. In principal component analysis (PCA), 73.079% of the variance was explained with four components. Plant-available B in the soil was significantly correlated with phosphorus, potassium, pH, and electrical conductivity (EC), showing that phosphorus and potassium fertilizer producers would be adding boron to fertilizers, although it is not mentioned on their packages. Also, the tide correlation between B and either soil pH and EC was attributed to greater solubility B, pH and EC. The majority of the experimental soils were deficient in boron. Therefore, boron fertilizer must be added to the fertilization program to mitigate the losses caused by boron deficiency in low-input agricultural production fields.