154 research outputs found
Enhanced wheat yield by biochar addition under different mineral fertilization levels
Climate change and global warming have worldwide
adverse consequences. Biochar production and its use in
agriculture can play a key role in climate change mitigation
and help improve the quality and management of waste materials
coming from agriculture and forestry. Biochar is a carbonaceous
material obtained from thermal decomposition of
residual biomass at relatively low temperature and under
oxygen limited conditions (pyrolysis). Biochar is currently a
subject of active research worldwide because it can constitute
a viable option for sustainable agriculture due to its potential
as a long-term sink for carbon in soil and benefits for crops.
However, to date, the results of research studies on biochar
effects on crop production show great variability, depending
on the biochar type and experimental conditions. Therefore, it
is important to identify the beneficial aspects of biochar addition
to soil on crop yield in order to promote the adoption of
this practice in agriculture. In this study, the effects of two
types of biochar from agricultural wastes typical of Southern
Spain: wheat straw and olive tree pruning, combined with
different mineral fertilization levels on the growth and yield
of wheat (Triticum durum L. cv. Vitron) were evaluated.
Durum wheat was pot-grown for 2 months in a growth chamber
on a soil collected from an agricultural field near CĂłrdoba,
Southern Spain. Soil properties and plant growth variables
were studied in order to assess the agronomic efficiency of
biochar. Our results show that biochar addition to a nutrientpoor,
slightly acidic loamy sand soil had little effect on wheat
yield in the absence of mineral fertilization. However, at the
highest mineral fertilizer rate, addition of biochar led to about
20–30 % increase in grain yield compared with the use of the
mineral fertilizer alone. Both biochars acted as a source of
available P, which led to beneficial effects on crop production.
In contrast, the addition of biochar resulted in decreases in
available N and Mn. A maximum reduction in plant nutrient
concentration of 25 and 80% compared to nonbiochar-treated
soils for N and Mn, respectively, was detected. This fact was
related to the own nature of biochar: low available nitrogen
content, high adsorption capacity, and low mineralization rate
for N; and alkaline pH and high carbonate content for Mn. Our
results indicate that biochar-based soil management strategies
can enhance wheat production with the environmental benefits
of global warming mitigation. This can contribute positively
to the viability and benefits of agricultural production
systems. However, the nutrient–biochar interactions should
receive special attention due to the great variability in the
properties of biochar-type materials
MRI of the kidney—state of the art
Ultrasound and computed tomography (CT) are modalities of first choice in renal imaging. Until now, magnetic resonance imaging (MRI) has mainly been used as a problem-solving technique. MRI has the advantage of superior soft-tissue contrast, which provides a powerful tool in the detection and characterization of renal lesions. The MRI features of common and less common renal lesions are discussed as well as the evaluation of the spread of malignant lesions and preoperative assessment. MR urography technique and applications are discussed as well as the role of MRI in the evaluation of potential kidney donors. Furthermore the advances in functional MRI of the kidney are highlighted
Atmospheric electrification in dusty, reactive gases in the solar system and beyond
Detailed observations of the solar system planets reveal a wide variety of local atmospheric conditions. Astronomical observations have revealed a variety of extrasolar planets none of which resembles any of the solar system planets in full. Instead, the most massive amongst the extrasolar planets, the gas giants, appear very similar to the class of (young) Brown Dwarfs which are amongst the oldest objects in the universe. Despite of this diversity, solar system planets, extrasolar planets and Brown Dwarfs have broadly similar global temperatures between 300K and 2500K. In consequence, clouds of different chemical species form in their atmospheres. While the details of these clouds differ, the fundamental physical processes are the same. Further to this, all these objects were observed to produce radio and X-ray emission. While both kinds of radiation are well studied on Earth and to a lesser extent on the solar system planets, the occurrence of emission that potentially originate from accelerated electrons on Brown Dwarfs, extrasolar planets and protoplanetary disks is not well understood yet. This paper offers an interdisciplinary view on electrification processes and their feedback on their hosting environment in meteorology, volcanology, planetology and research on extrasolar planets and planet formation
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