Browsing by Author "Liu, Chunjiang"

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    The value of manure - Manure as co-product in life cycle assessment
    (Elsevier, 2019-04-19) Leip, Adrian; Ledgard, Stewart; Uwizeye, Aimable; Palhares, Julio C.P.; Fernanda Aller, M.; Amon, Barbara; Binder, Michael; Cordovil, Claudia M.d.S.; De Camillis, Camillo; Dong, Hongming; Fusi, Alessandra; Helin, Janne; Hörtenhuber, Stefan; Hristov, Alexander N.; Koelsch, Richard; Liu, Chunjiang; Masso, Cargele; Nkongolo, Nsalambi V.; Wang, Ying
    Livestock production is important for food security, nutrition, and landscape maintenance, but it is associated with several environmental impacts. To assess the risk and benefits arising from livestock production, transparent and robust indicators are required, such as those offered by life cycle assessment. A central question in such approaches is how environmental burden is allocated to livestock products and to manure that is re-used for agricultural production. To incentivize sustainable use of manure, it should be considered as a co-product as long as it is not disposed of, or wasted, or applied in excess of crop nutrient needs, in which case it should be treated as a waste. This paper proposes a theoretical approach to define nutrient requirements based on nutrient response curves to economic and physical optima and a pragmatic approach based on crop nutrient yield adjusted for nutrient losses to atmosphere and water. Allocation of environmental burden to manure and other livestock products is then based on the nutrient value from manure for crop production using the price of fertilizer nutrients. We illustrate and discuss the proposed method with two case studies.
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    Variation of Oriental Oak (Quercus variabilis) Leaf δ13C across Temperate and Subtropical China: Spatial Patterns and Sensitivity to Precipitation
    (MDPI, 2015-06-30) Du, Baoming; Kang, Hongzhang; Zhu, Yanhua; Zhao, Xuan; Yin, Shan; Burgess, Paul J.; Liu, Chunjiang
    The concentration of the carbon-13 isotope (leaf δ13C) in leaves is negatively correlated with the mean annual precipitation (MAP) atlarge geographical scales. In this paper, we explain the spatial pattern of leaf δ13C variation for deciduous oriental oak (Quercus variabilis Bl.) across temperate and subtropical biomes and its sensitivity to climate factors such as MAP. There was a 6‰ variation in the leaf δ13C values of oak with a significant positive correlation with latitude and negative correlations with the mean annual temperature (MAT) and MAP. There was no correlation between leaf δ13C and altitude or longitude. Stepwise multiple regression analyses showed that leaf δ13C decreased 0.3‰ per 100 mm increase in MAP. MAP alone could account for 68% of the observed variation in leaf δ13C. These results can be used to improve predictions for plant responses to climate change and particularly lower rainfall.