Comparison of chemical characteristics of shoot, root and litter in three range species of Salsola rigida, Artemisia sieberi and Stipa barbata

Some chemical characteristics of root, shoot and litter of index species such as Salsola rigida, Artemisia sieberi and Stipa barbata commonly used in rangeland development projects were evaluated and compared. Chemical properties of soil under and between the above mentioned species were also studied. For this purpose, vegetation types of Stipa barbata and Artemisia sieberi - Salsola rigida were selected in Zarand-eSaveh rangelands. Totally, 30 individuals of each species within each type were randomly selected for shoot, root and litter sampling and chemical analyses. Also, values of N, P, K, C and C/N ratio were measured in different parts of the species. Results showed that the highest and lowest C/N ratios were related to Stipa barbata root and Artemisia sieberi shoots, respectively. N and P values of Stipa barbata litter were the lowest while Artemisia sieberi and Salsola rigida shoots had the highest values of P and N, respectively. Litter of Salsola rigida and shoot of Artemisia sieberi had the lowest and highest K, respectively. C/N ratio of A. sieberi soil was lower than rest of the species

Investigação sobre a captação e acúmulo de chumbo e zinco por stipa hohenackeriana trin. & rupr. em experimentos de campo e em vaso

13 páginas.-- 8 tablas.-- 40 referencias.-- the articles are free to use, with proper attribution, in educational and non- commercial applications.[EN]: This study was conducted to evaluate Pb and Zn uptake, mobility, and accumulation in Stipa hohenackeriana using field soil in pot and field experiments. Moreover, the effects of Municipal Solid Waste Compost (MSWC) (0, 1, and 2%) and Nano-Silica (NS) (0, 250, and 500 mg/kg) on Stipa biomass, Pb and Zn availability in the soil, and Pb and Zn uptake and accumulation were studied using pot experiments. Samples of soil, root, and shoots of Stipa were collected from field and greenhouse and after drying, extraction of Pb and Zn was done by acid digestion. Bio-Concentration Factor (BCF) and Translocation Factor (TF) were calculated to determine Pb and Zn phytoremediation efficiency. The amount of Zn and Pb remediation by Stipa from soil was determined by remediation factor (RF). The results of field experiments showed the Pb and Zn level decreased in the order of: soil >shoot>root. Results of the pot experiments also showed that plants grown in NS500-amended pots had 33% and 32% higher Pb in roots and shoots compared to control pots, respectively. In comparison, roots Pb concentration in pots amended with MSWC1% and MSWC2% decreased 22.4% and 1.7%, respectively. Roots and shoots Zn concentration in NS500-amended pots was 5.6% and 6.5% higher, respectively. However, root Zn concentration in treatments of MSWC1% and MSWC2% decreased 52.3% and 39.4%, respectively. Shoots Zn concentration decreased 52.5% and 40.0%, respectively. Although MSWC decreased the uptake and accumulation of Pb and Zn in Stipa roots and shoots, it improved the plant growth and consequently increased RF and soil remediation compared to the NS. Thus, it seems that applying MSWC and NS simultaneously can be a suitable strategy for the purpose of improving phytoremediation capability of Stipa in the Pb and Zn contaminated soils. In general, Stipa can be a suitable candidate for the accumulation of heavy metals, especially for Pb and Zn contaminated soils.[PO]: Este estudo foi conduzido para avaliar a absorção, mobilidade e acumulação de Pb e Zn em Stipa hohenackeriana em experiências usando solo de campo em vaso e em campo. Além disso, os efeitos do Composto Municipal de Resíduos Sólidos (MSWC) (0, 1 e 2%) e de nanopartículas de sílica (NS) (0, 250 e 500 mg/kg) na biomassa de Stipa, na disponibilidade de Pb e Zn no solo, e na absorção e acúmulo de Pb e Zn foram estudados usando experiências em vaso. Amostras de solo, raiz e brotos de Stipa foram coletadas do campo e da estufa e, após a secagem, a extração de Pb e Zn foi feita por digestão ácida. O Fator de Bioconcentração (BCF) e o Fator de Translocação (TF) foram calculados para determinar a eficiência de fitorremediação de Pb e Zn. A quantidade de remediação de Zn e Pb pela Stipa a partir do solo foi determinada pelo Fator de Remediação (RF). Os resultados das experiências de campo mostraram que o nível de Pb e Zn diminuiu na seguinte ordem: solo > broto > raiz. Os resultados das experiências em vaso também mostraram que as plantas cultivadas em vasos corrigidos com NS500 apresentaram teores de Pb 33% e 32% maiores em raízes e brotos em comparação com vasos de controle, respectivamente. Em comparação, a concentração de Pb em raízes em vasos corrigidos com MSWC1% e MSWC2% diminuiu 22,4% e 1,7%, respectivamente. A concentração de Zn em raízes e brotos em vasos corrigidos com NS500 foi de 5,6% e 6,5% maior, respectivamente. No entanto, a concentração de Zn da raiz nos tratamentos de MSWC1% e MSWC2% diminuiu 52,3% e 39,4%, respectivamente. A concentração de Zn nos brotos diminuiu 52,5% e 40,0%, respectivamente. Embora o MSWC tenha diminuído a absorção e acumulação de Pb e Zn nas raízes e brotos de Stipa, melhorou o crescimento da planta e consequentemente aumentou o RF e a remediação do solo em relação ao NS. Assim, parece que aplicar MSWC e NS simultaneamente pode ser uma estratégia adequada com o objetivo de melhorar a capacidade de fitorremediação de Stipa nos solos contaminados com Pb e Zn. Em geral, a Stipa pode ser um candidato adequado para a acumulação de metais pesados, especialmente para solos contaminados com Pb e Zn.Peer reviewe

Comparing Some Properties of Crusted and Uncrusted Soils in Alagol Region of Iran

Abstract: The current research was carried out to study effects of biological soil crusts (lichens and mosses) on some soil attributes. The study was carried out in rangelands of Alagol region, in north of Golestan province, Northern Iran. Survey area is located near Iran-Turkmenistan border. In this research, soil samples were taken from two crusted and adjacent uncrusted areas, at one site along 4 transects. Environmental factors, soil texture and vascular plants vegetation of two areas were similar, but due to livestock repeated trampling and wind and water erosion over the last years, there were not lichens and mosses in non-crusted points. Soil sampling was done along each of two transverse 300m transects. Laboratory analyses were done on soil samples from the upper soil layer (0-5 cm). Soil properties included organic C, K, Na, N, and P. Using t-test, above mentioned properties were compared in crusted and uncrusted soils. Results showed that P, N, and organic C were significantly different at depth 0-5 cm. Key words: Biological soil crust, crusted soil, soil characteristics, arid and semi-arid lands, rangelan