33 research outputs found
Narrowing the Agronomic Yield Gaps of Maize by Improved Soil, Cultivar, and Agricultural Management Practices in Different Climate Zones of Northeast China
Citation: Liu, Z. J., Yang, X. G., Lin, X. M., Hubbard, K. G., Lv, S., & Wang, J. (2016). Narrowing the Agronomic Yield Gaps of Maize by Improved Soil, Cultivar, and Agricultural Management Practices in Different Climate Zones of Northeast China. Earth Interactions, 20, 18. doi:10.1175/ei-d-15-0032.1Northeast China (NEC) is one of the major agricultural production areas in China, producing about 30% of China's total maize output. In the past five decades, maize yields in NEC increased rapidly. However, farmer yields still have potential to be increased. Therefore, it is important to quantify the impacts of agronomic factors, including soil physical properties, cultivar selections, and management practices on yield gaps of maize under the changing climate in NEC in order to provide reliable recommendations to narrow down the yield gaps. In this study, the Agricultural Production Systems Simulator (APSIM)-Maize model was used to separate the contributions of soil physical properties, cultivar selections, and management practices to maize yield gaps. The results indicate that approximately 5%, 12%, and 18% of potential yield loss of maize is attributable to soil physical properties, cultivar selection, and management practices. Simulation analyses showed that potential ascensions of yield of maize by improving soil physical properties PAY(s), changing to cultivar with longer maturity PAY(c), and improving management practices PAY(m) for the entire region were 0.6, 1.5, and 2.2 ton ha(-1) or 9%, 23%, and 34% increases, respectively, in NEC. In addition, PAY(c) and PAY(m) varied considerably from location to location (0.4 to 2.2 and 0.9 to 4.5 ton ha(-1) respectively), which may be associated with the spatial variation of growing season temperature and precipitation among climate zones in NEC. Therefore, changing to cultivars with longer growing season requirement and improving management practices are the top strategies for improving yield of maize in NEC, especially for the north and west areas
Non-Invasive Optical Sensor with Control of Tissue Temperature
Devices and methods for non-invasively measuring at least one parameter of a sample, such as the presence or concentration of an analyte, in a body part wherein the temperature is controlled. The present invention measures light that is reflected, scattered, absorbed, or emitted by the sample from an average sampling depth, dav, that is confined within a temperature controlled region in the tissue. This average sampling depth is preferably less than 2 mm, and more preferably less than I mm. Confining the sampling depth into the tissue is achieved by appropriate selection of the separation between the source and the detector and the illumination wavelengths. In another aspect, the invention involves a method and apparatus for non-invasively measuring at least one parameter of a body part with temperature stepping. In another aspect, the invention involves a method and apparatus for non-invasively measuring at least one parameter of a body part with temperature modulation. In another aspect, the invention provides an improved method of measuring at least one parameter of a tissue sample comprising the steps of: (a) lowering the temperature of said tissue sample to a temperature that is lower than the normal physiological temperature of the body; and (b) determining at least one optical property of said tissue sample
Documentation of uncertainties and biases associated with surface temperature measurement sites for climate change assessment
The use of temperature data from poorly sited stations can lead to a false sense of confidence in the robustness of multidecadal surface air temperature trend assessments. Davey and Pielke (2005) presented photographic documentation of poor observation sites within the U.S. Historical Climate Reference Network (USHCN) with respect to monitoring long-term surface air temperature trends. [These photographs were first shown to the community at the 2002 Asheville, North Carolina, meeting of the American Association of State Climatologists (see information online at www. stateclimate.org/meetings/minutes/2002minutes).] Peterson (2006) compared the adjusted climate records of many of these stations and concluded that... the similarity between the homogeneityadjusted time series from the good and poorly sited stations supports the view that even station