991 resultados para nitrogen fertilizers
Resumo:
We measured the stable carbon and nitrogen isotope ratios for muscles of the upland buzzards (Buteo hemilasius) and their potential food sources, plateau pikas (Ochotona curzoniae), Qinghai voles (Lasiopodomys fuscus), plateau zokors (Myospalax fontanierii), and several passerine bird species at the alpine meadow in Maduo county, Guoluo prefecture of Qinghai province, People's Republic of China, to provide diet information of upland buzzards, highlighting different diet composition of upland buzzards exposed to different locations. The results demonstrated that stable carbon isotope ratios of upland buzzards, passerine birds, plateau pikas, plateau zokors, and Qinghai voles were -24.42 +/- 0.25parts per thousand, -22.89 +/- 1.48parts per thousand, -25.30 +/- 1.47parts per thousand, -25.78 +/- 0.22parts per thousand, and -25.41 +/- 0.01parts per thousand, respectively, and stable nitrogen isotope ratios were 7.89 +/- 0.38parts per thousand, 8.37 +/- 2.05parts per thousand, 5.83 +/- 1.10parts per thousand, 5.23 +/- 0.34parts per thousand, and 8.86 +/- 0.06parts per thousand, respectively. Fractionation of stable carbon and nitrogen isotope ratios between upland buzzards and their food were 1.03parts per thousand and 2.11parts per thousand, respectively. Based on mass balance principle of stable isotopes and the Euclidean distance mixing model, upland buzzards depended mainly on plateau pikas as food (74.56%). Plateau zokors, Qinghai voles, and passerine birds only contributed a small proportion (25.44%) to diets of upland buzzards. The results were closely accordant with analyses of stomach contents and food pellets, which firmly supported the feasibility of using stable carbon and nitrogen isotope ratios to investigate diet information of upland buzzards. Another study based on stable carbon isotopes showed that upland buzzards living in the Haibei prefecture (another prefecture located in the southeast Qinghai province) mainly preyed on passerine birds (64.96% or more) as food supply. We were alarmed by the preliminary results that widespread poisoning activities of small mammals could reshape the food composition of upland buzzards, influencing the stability and sustainability of the alpine meadow. Bio-control on rodent pests should be carried out rather than the chemical measures.
Resumo:
The context: Soil biodiversity and sustainable agriculture; Abstracts - Theme 1: Monitoring and assessment: Bioindicators of soil health: assessment and monitoring for sustainable agriculture; Practical tools to measure soil health and their use by farmers; Biological soil quality from biomass to biodiversity - importance and resilience to management stress and disturbance; Integrated management of plant-parasitic nematodes in maize-bean cropping systems; Microbial quantitative and qualitative changes in soils under different crops and tillage management systems in Brazil; Diversity in the rhizobia associated with Phaseolus vulgaris L: in Ecuador and comparisons with Mexican bean rhizobia; Sistemas integrados ganadería-agricultura en Cuba; Soil macrofauna as bioindicator of soil quality; Biological functioning of cerrado soils; Hydrolysis of fluorescein diacetate as a soil quality indicator in different pasture systems; Soil management and soil macrofauna communities at Embrapa Soybean, Londrina, Brazil; Soil macrofauna in a 24 - year old no-tillage system in Paraná, Brazil; Invertebrate macrofauna of soils inpastures under different forms of management in the cerrado (Brazil); Soil tillage modifies the invertebrate soil macrofauna community; Soil macrofauna in various tillage and land use systems on an oxisols near Londrina, Paraná, Brazil; Interference of agricultural systems on soil macrofauna; Scarab beetle-grub holes in various tillage and crop management systems at Embrapa Soybean, Londrina, Brazil; Biological management of agroecosystems; Soil biota and nutrient dynamics through litterfall in agroforestry system in Rondônia, Amazônia, Brazil; Soil-C stocks and earthworm diversity of native and introduced pastures in Veracruz, Mexico; Theme 2 : Adaptive management: Some thoughts on the effects and implications of the transition from weedy multi-crop to wead-free mono-crop systems in Africa; Towards sustainable agriculture with no-tillage and crop rotation systems in South Brazil; Effect of termites on crusted soil rehabilitation in the Sahel; Management of macrofauna in traditional and conventional agroforestry systems from India with special reference to termites and earthworms; Adaptive management for redeveloping traditional agroecosystems; Conservation and sustainable use of soil biodiversity: learning with master nature!; Convergence of sciences: inclusive technology innovation processes for better integrated crop/vegetation, soil and biodiversity management; Potential for increasing soil biodiversity in agroecosystems; Biological nitrogen fixation and sustainability in the tropics; Theme 3: Research and innovation: Plant flavonoids and cluster roots as modifiers of soil biodiversity; The significance of biological diversity in agricultural soil for disease suppressiveness and nutrient retention; Linking above - and belowground biodiversity: a comparison of agricultural systems; Insect-pests in biologically managed oil and crops: the experience at ICRISAT; Sistemas agricolas micorrizados en Cuba; The effect of velvetbean (Mucuna pruriens) on the tropical earthworm Balanteodrilus pearsei: a management option for maize crops in the Mexican humid tropics; The potential of earthworms and organic matter quality in the rehabilitation of tropical soils; Research and innovation in biological management of soil ecosystems; Application of biodynamic methods in the Egyptian cotton sector; Theme 4: Capacity building and mainstreaming: Soil ecology and biodiversity: a quick scan of its importance for government policy in The Netherlands; Agrotechnological transfer of legume inoculants in Eastern and Southern Africa; Agricultura urbana en Cuba; Soil carbon sequestration for sustaining agricultural production and improving the environment; Conservation and sustainable management of below-ground biodiversity: the TSBF-BGBD network project; The tropical soil biology and fertility institute of CIAT (TSBF); South-South initiative for training and capacity building for the management of soil biology/biodiversity; Strategies to facilititate development and adoption of integrated resource management for sustainable production and productivity improvement; The challenge program on biological nitrogen fixation (CPBNF); Living soil training for farmers: improving knowledge and skills in soil nutrition management; Do we need an inter-governmental panel on land and soil (IPLS)? Protection and sustainable use of biodiversity of soils; Cases Studies -- Plant parasitic nematodes associated with common bean (Phaseolus vulgaris L.) and integrated management approaches; Agrotechnological transfer of legume inoculants in Eastern and Southern Africa; Restoring soil fertility and enhancing productivity in Indian tea plantations with earthworms and organic fertilizers; Managing termites and organic resources to improve soil productivity in the Sahel; Overview and case studies on biological nitrogen fixation: perspectives and limitations; Soil biodiversity and sustainable agriculture: an overview.
Resumo:
A stainless-steel net is used to support a zeolite NaA membrane synthesized using a 'seeded-growth' method. The zeolite and stainless-steel net are tightly integrated (see Figure), showing large-scale order and high mechanical stability. High oxygen permeance and high permselectivity for O-2 over N-2 (about 7) is demonstrated.
Resumo:
A novel poly sulfone/polyethylene oxide/silicone rubber (PSOPEO/SR) multilayer composite membrane was fabricated by double coating polysulfone substrate membrane with polyethylene oxide and silicone rubber. Gas permeation experiments were performed at 30 degrees C for hydrogen and nitrogen. PSf(PEO/SR membrane displayed high and steady performance for H-2/N-2: permeances of H-2 and N-2 of 49.51 and 0.601 GPU, respectively, and H-2/N-2 ideal separation factor of 82.3. It was explained that layer interfaces due to the introduction of PEO layer act as the permselective media and are responsible for the higher H-2/N-2 ideal separation factor which has exceeded the intrinsic permselectivities of the three polymers used in this study. (c) 2005 Elsevier B.V. All rights reserved.
Resumo:
Macduff, J. H., Humphreys, M. O., Thomas, Howard (2002). Effects of a stay-green mutation on plant nitrogen relations in Lolium perenne during N starvation and after defoliation. Annals of Botany, 89 (1), 11-21. Sponsorship: BBSRC RAE2008
Resumo:
Donnison, I. S., Gay, A. P., Thomas, Howard, Edwards, K. J., Edwards, D., James, C. L., Thomas, A. M., Ougham, H. J. (2007). Modification of nitrogen remobilization, grain fill and leaf senescence in maize (Zea mays) by transposon insertional mutagenensis in a protease gene. New Phytologist, 173 (3), 481-494. Sponsorship: BBSRC RAE2008
Resumo:
James Macduff, Neil Raistrick and Mervyn Humphreys (2002). Differences in growth and nitrogen productivity between a stay-green genotype and a wild-type of Lolium perenne under limiting relative addition rates of nitrate supply. Physiologia Plantarum, 116 (1), 52-61. Sponsorship: BBSRC RAE2008