Bai Y.,Northwest University, China |
Wang Y.,CAS Institute of Soil and Water Conservation
Soil Science | Year: 2011
An understanding of spatial variability for soil chemical properties is essential in optimizing fertilization and sustaining yield. The objective of this study was to investigate the spatial variability of soil chemical properties in a 10-year-old jujube trees hillslope (2,725 m) on the Loess Plateau of China. A total of 250 soil samples were collected at two depths (0-10 and 10-30 cm) in August 2010. Soil organic carbon (SOC), total nitrogen (TN), total phosphorus, pH, and electrical conductivity were determined for all soil samples, and data were analyzed by the classic and geostatistical methods. Classic statistics showed that soil organic carbon, TN, total phosphorus, and electrical conductivity had moderate variability, and pH had low variability. Soil organic carbon and TN in the lower position were significantly greater than in the upper and middle positions (P < 0.01), whereas pH in the middle slope was significantly greater than the other positions (P < 0.01). The geostatistical statistics results showed that the soil chemical properties were defined by the exponential or spherical models. The nugget-to-sill ratios indicated that all soil chemical properties had moderate dependences. The results of cross-validation showed that spatial prediction maps from ordinary kriging method were reliable in the study slope (the kriged reduced mean square error higher than 0.99 and the kriged average error close to 0). These results and maps could provide useful information for the development and application of precision agriculture on the Loess Plateau. © 2011 by Lippincott Williams & Wilkins.
He H.,CAS Institute of Soil and Water Conservation |
He H.,Chinese Ministry of Water Resources |
He H.,University of Western Australia |
Veneklaas E.J.,University of Western Australia |
And 2 more authors.
Trends in Plant Science | Year: 2014
Biomineralization is widespread in the plant kingdom. The most common types of biominerals in plants are calcium oxalate crystals, calcium carbonate, and silica. Functions of biominerals may depend on their shape, size, abundance, placement, and chemical composition. In this review we highlight advances in understanding physiological and ecological significance of biomineralization in plants. We focus on the functions of biomineralization in regulating cytoplasmic free calcium levels, detoxifying aluminum and heavy metals, light gathering and scattering to optimize photosynthesis, aiding in pollen release, germination, and tube growth, the roles it plays in herbivore deterrence, biogeochemical cycling of carbon, calcium, and silicon, and sequestering atmospheric CO2. © 2013 Elsevier Ltd.
Peng P.,Northwest University, China |
She D.,Northwest University, China |
She D.,CAS Institute of Soil and Water Conservation
Carbohydrate Polymers | Year: 2014
Bamboo is one of the mostly fast growing natural resources and has great potential to be used as a valuable feedstock for biorefinery. The hemicelluloses, next to cellulose, represent a diverse group of polysaccharides in plant cell wall. Elucidation and understanding of the hemicelluloses from bamboo play an important role in the efficient conversion of bamboo into biofuels and bioproducts. This review summarized the recent reports on hemicelluloses from bamboo, including immunohistochemical localization, focused on extraction and purification methods, chemical components, characterization of structural features, as well as physicochemical properties. In addition, attention was also paid to derivatives prepared from bamboo hemicelluloses and to potential applications of bamboo hemicelluloses in a variety of areas such as biomaterials, biofuel, and food. © 2014 Elsevier Ltd. All rights reserved.
Chen J.,CAS Institute of Soil and Water Conservation |
Chen J.,University of Quebec |
Brissette F.P.,University of Quebec
Climate Research | Year: 2014
The present study first reviews the performance of different models in generating daily precipitation amounts. Eight models with different levels of complexity are then selected to simulate daily precipitation for 35 stations across the world. All 8 models adequately reproduce the observed mean precipitation at daily, monthly and annual scales, while all of them underestimate the standard deviation of monthly and annual precipitation. However, the compound distributions are generally better than the single distributions at reducing the variance overdispersion, with the exception of the skewed normal (SN) distribution. The nonparametric kernel density estimation (KDE) is consistently better than all the parametric distributions. With the exception of the SN distribution, all the single distributions underestimate the upper tail of daily precipitation distribution. However, the generalized Pareto distribution-based compound distributions provide a reasonable performance for simulating the upper tail, even though they are slightly worse than the KDE, which displays the best performance. Overall, the compound distributions generally perform better than the single distributions, and the nonparametric KDE performs better than the parametric distributions. However, the complicated structure of the compound distribution and of the KDE and the limited extrapolation ability of the KDE may restrict their application to climate change impact studies. The 3-parameter SN distribution displays a similar or even slightly better performance than the compound distributions, and this distribution may be the first choice to be incorporated into a weather generator for studying climate change impacts, especially for risk-related assessments. © Inter-Research 2014.
Rhodia, CAS Institute of Soil and Water Conservation | Date: 2012-10-23
Provided is a method for preventing soil erosion in which a nonionic guar and/or a cationic guar is applied on or into the soil. A method for preventing water runoff of a soil in which a nonionic guar and/or a cationic guar is applied on or into the soil is also provided. A treated soil against the soil erosion susceptible to be obtained by the method for preventing soil erosion in which a nonionic guar and/or a cationic guar is applied on or into the soil is also provided.