High-altitude (HA) natives have blunted ventilatory sensitivities to hypoxia, and it is uncertain whether this blunting is reversible on migration to sea level (SL). To study this, the ventilatory sensitivities to hypoxia of HA natives residing near SL were compared with those of SL natives. Two studies were performed. In study A, 24 HA subjects who had lived above 3,000 m for an average of 14 ...

were exposed to two concentrations of atmospheric CO2 (365 or 720 μmol mol) in combination with two N treatments (40 or 400 kg N ha year) and two irrigation treatments (target values of −0.5 or −1.5 MPa xylem pressure potential) in opentop chambers from March 1993 through November 1994. Irrigation treatments were imposed after seedling establishment (i.e., 19 weeks after planting). Seedlings we...

Wheat is one of the world's most favoured food sources, reaching millions of people on a daily basis. However, its production has climatic consequences. Fuel, inorganic fertilizers and pesticides used in wheat production emit greenhouse gases that can contribute negatively to climate change. It is unknown whether adopting alternative farming practices will increase crop yield while reducing car...

fertilization on shoot and fine root growth of Pinus ponderosa Dougl. ex P. Laws. and C. Laws. grown in native soil in open-top field-exposure chambers at Placerville, CA, over a 2-year period. The experimental design was a replicated 3 × 3 factorial with the center treatment missing; plants were exposed to ambient (~365 μmol mol) air or ambient air plus either 175 or 350 μmol mol CO2 in combin...

objective: the aims of this study were to determine energy efficiency and co2 use pattern of grape production in zanjan province, iran by a non-parametric method of data envelopment analysis (dea). methods: initial data were collected using a face to face questionnaire from 42 orchards in abhar city of zanjan province which is one of the most important centers of grape production in iran. the d...

Elevated atmospheric CO2 may alter decomposition rates through changes in plant material quality and through its impact on soil microbial activity. This study examines whether plant material produced under elevated CO2 decomposes differently from plant material produced under ambient CO2. Moreover, a long-term experiment offered a unique opportunity to evaluate assumptions about C cycling under...

The present study provides a synthesis of the in vitro and in vivo temperature responses of Rubisco Michaelis-Menten constants for CO2 (Kc) and O2 (Ko), specificity factor (Sc,o) and maximum carboxylase turnover rate (kcatc) for 49 species from all the main photosynthetic kingdoms of life. Novel correction routines were developed for in vitro data to remove the effects of study-to-study differe...

The response of wheat crops to elevated CO2 (eCO2 ) was measured and modelled with the Australian Grains Free-Air CO2 Enrichment experiment, located at Horsham, Australia. Treatments included CO2 by water, N and temperature. The location represents a semi-arid environment with a seasonal VPD of around 0.5 kPa. Over 3 years, the observed mean biomass at anthesis and grain yield ranged from 4200 ...

Understanding how carbon, nitrogen, and key soil attributes affect gas emissions from soil is crucial for alleviating their undesirable residual effects that can linger for years after termination of manure and compost applications. This study was conducted to evaluate the emission of soil CO2, N2O, and CH4 and soil C and N indicators four years after manure and compost application had stopped....