|
| ||
|
|
||
Cm Soil Depth (cm + soil_depth)
Selected AbstractsEffects of wastewater irrigation on soil and cabbage-plant (brassica olerecea var. capitate cv. yalova-1) chemical propertiesJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 1 2007Fatih M. Kiziloglu Abstract 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. [source] Effect of young woody plantations on carbon and nutrient accretion rates in a redeveloping soil on coalmine spoil in a dry tropical environment, IndiaLAND DEGRADATION AND DEVELOPMENT, Issue 1 2006A. N. Singh Abstract We compared the effects of young high-density plantations of three native trees (legumes: Albizia lebbeck, A. procera and a non-legume: Tectona grandis) and one fast growing woody grass species (Dendrocalamus strictus) on carbon and nutrients stock and their accretion rates in a redeveloping soil. This soil was the early phase of mine spoil restoration in a dry tropical environment. The soil bulk density and accumulation rates of C, N and P at 0,10 and 10,20,cm soil depth were determined in 4- to 5-year-old plantations. The total nutrient stock of soil C, N, P significantly varied in redeveloping soil according to plantation type, plantation age and soil depth. A. lebbeck greatly improved C and N content followed by D. strictus, A. procera and T. grandis plantations. However, accretion rates of C and N were substantially high in the D. strictus plantation. Therefore, D. strictus, contributed significantly to the redevelopment of mine spoil soils. In the case of total P nutrient, A. procera showed the greatest amount among the plantations but the accretion rate was also high for T. grandis followed by A. procera, A. lebbeck and D. strictus. This study indicates that all N-fixing species may not be equally efficient in improving soil qualities especially N in the soil. Copyright © 2006 John Wiley & Sons, Ltd. [source] CO2 enrichment increases carbon and nitrogen input from fine roots in a deciduous forestNEW PHYTOLOGIST, Issue 3 2008Colleen M. Iversen Summary ,,Greater fine-root production under elevated [CO2] may increase the input of carbon (C) and nitrogen (N) to the soil profile because fine root populations turn over quickly in forested ecosystems. ,,Here, the effect of elevated [CO2] was assessed on root biomass and N inputs at several soil depths by combining a long-term minirhizotron dataset with continuous, root-specific measurements of root mass and [N]. The experiment was conducted in a CO2 -enriched sweetgum (Liquidambar styraciflua) plantation. ,,CO2 enrichment had no effect on root tissue density or [N] within a given diameter class. Root biomass production and standing crop were doubled under elevated [CO2]. Though fine-root turnover declined under elevated [CO2], fine-root mortality was also nearly doubled under CO2 enrichment. Over 9 yr, root mortality resulted in 681 g m,2 of extra C and 9 g m,2 of extra N input to the soil system under elevated [CO2]. At least half of these inputs were below 30 cm soil depth. ,,Increased C and N input to the soil under CO2 enrichment, especially below 30 cm depth, might alter soil C storage and N mineralization. Future research should focus on quantifying root decomposition dynamics and C and N mineralization deeper in the soil. [source] Soil Charcoal in Old-Growth Rain Forests from Sea Level to the Continental DivideBIOTROPICA, Issue 6 2007Beyhan Titiz ABSTRACT Soil charcoal is an indicator of Holocene fires as well as a palaeoecological signature of pre-Colombian land use in Neotropical rain forests. To document rain forest fire history, we examined soil charcoal patterns in continuous old-growth forests along an elevational transect from sea level to the continental divide on the Atlantic slope of Costa Rica. At 10 elevations we sampled 1-ha plots, using 16 cores/ha to collect 1.5-m deep soil samples. We found charcoal in soils at every elevation, with total dry mass ranging from 3.18 g/m2 at 2000-m elevation to as much as 102.7 g/m2 at 300 m. Soil charcoal is most abundant at the wettest lowland sites (60,500 m) and less at montane elevations (> 1000 m) where there is less rainfall. Between 30- and 90-cm soil depth, soil charcoal is present consistently and every 1-ha plot has charcoal evidence for multiple fire events. Radiocarbon dates range from 23,240 YBP at 1750-m elevation to 140 YBP at 2600 m. Interestingly, none of the charcoal samples from 2600 m are older than 170 yr, which suggests that forests near the continental divide are relatively young replacement stands that have re-established since the most recent localized volcanic eruption on Volcán Barva. We propose that these old-growth forests have been disturbed infrequently but multiple times as a consequence of anthropogenic and natural fires. RESUMEN El carbón es un indicador de los fuegos Holocenos así como una huella paleoecológica del uso de las tierras precolombinas en bosques neotropicales. Para documentar la historia de fuegos en los bosques, examinamos modelos de carbón en la tierra en bosques primarios continuos a lo largo de un transecto en altitud en zonas de vida forestal desde el nivel del mar hasta la División Continental en la vertiente atlántica de Costa Rica. En diez elevaciones tomamos muestras de parcelas de una hectárea, donde se usaron dieciséis cilíndricas de acero por hectárea para recoger muestras de suelo a 1.5 metros de profundidad. Descubrimos carbón en suelos en cada elevación, con un rango de masa seca total desde los 3.18 g/m2 a 2000 metros de altura hasta un máximo de 102.7 g/m2 a 300 metros de altura. El carbón abunda más en las zonas más lluviosas (60,500 metros) y menos en elevaciones montañosas (>1000 metros) donde hay menos precipitación. Entre los 30 a los 90 centímetros de profundidad en la tierra, el carbón está presente consistentemente y cada parcela de una hectárea tiene evidencia de carbón de incendios múltiples. Fechas de 14C van desde los 23,240 años a.P. a 1750 metros de elevación hasta los 140 años a.P. a 2600 metros. De modo interesante, ninguna de las muestras de carbón a partir de los 2600 metros de altura tiene más de 170 años, lo que sugiere que los bosques cerca de la División Continental son árboles relativamente jóvenes que se han reestablecido después de las erupciones volcánicas confinadas del Volcán Barva. Pensamos que estos bosques primarios han sido disturbados en muchas ocasiones pero en un largo periodo de tiempo como consecuencia de fuegos antropogénicos y naturales. [source] | |||||||||||||