Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Exploring optimal catch crops for reducing nitrate leaching in vegetable greenhouse in North China
Zhang, Hongyuan ; Hu, Kelin ; Zhang, Lijuan ; Ji, Yanzhi ; Qin, Wei - \ 2019
Agricultural Water Management 212 (2019). - ISSN 0378-3774 - p. 273 - 282.
Catch crop - Greenhouse vegetable field - N uptake - Nitrate leaching - Soil-crop system model

Chinese intensive greenhouse vegetable systems are characterized by high input of water and nutrients, which are not sustainable. There is an urgent need to explore smart and practical strategies to convert the “high input-low output” systems to “optimal input-output” ones. This study aimed to evaluate the effects of different catch crops on reducing nitrate leaching in the vegetable greenhouse during the summer fallow season. A two-year field experiment with three catch crops, i.e., sweet corn (SC), amaranth (A) and sweet sorghum (SG), and no catch crop (CK) were conducted in vegetable greenhouse in Dingzhou city, Hebei province, China. The measured soil water content and inorganic nitrogen (N) content in soil profile, biomass and crop N uptake were used to validate the WHCNS (Soil Water Heat Carbon Nitrogen Simulator) model, soil water movement and nitrate leaching were simulated. The results showed that the catch crops decreased the water drainage by 18.2–29.0% and nitrate leaching by 23.3–42.3% respectively, compared with CK. The water drainage reduction ranked as SC > SG > A, while the nitrate leaching reduction was A > SC > SG. The biomass was SC > SG > A, while the crop N uptake was SC > A > SG. Sweet corn could absorb the residual nitrate in the deep soil layers due to the long root system, while amaranth could absorb most residual nitrate in the surface soil. Amaranth showed greater N-uptake capacity than sweet corn, and the nitrate was mainly accumulated in the surface soil. Planting amaranth as summer catch crop reduced nitrate leaching in the vegetable greenhouses. Our study provides a guideline for selecting effective catch crops in intensive vegetable greenhouses in North China.

Irrigation reduces the negative effect of global warming on winter wheat yield and greenhouse gas intensity
Li, Jiazhen ; Dong, Wenxu ; Oenema, Oene ; Chen, Tuo ; Hu, Chunsheng ; Yuan, Haijing ; Zhao, Liying - \ 2019
Science of the Total Environment 646 (2019). - ISSN 0048-9697 - p. 290 - 299.
Global warming potential - Greenhouse gas intensity - Greenhouse gases - Irrigation - Warming - Wheat yield

Global warming may exacerbate drought, decrease crop yield and affect greenhouse gas (GHG) emissions in semi-arid regions. However, the interactive effects of increases in temperature and water availability on winter wheat yield and GHG emissions in semi-arid climates are not well-understood. Here, we report on a two-year field experiment that examined the effects of a mean soil temperature increase of ~2 °C (at 5 cm depth) with and without additional irrigation on wheat yield and GHG emissions. Infrared heaters were placed above the crop canopy at a height of 1.8 m to simulate warming. Fluxes of CH4, CO2 and N2O were measured using closed static chamber technique once per week during the wheat growing seasons. Warming decreased wheat yield by 28% in the relatively dry year of 2015, while supplemental irrigation nullified the warming effect completely. Warming did not alter the wheat yield significantly in the relatively wet year of 2016, but supplemental irrigation with no warming decreased the wheat yield by 25%. Warming increased CO2 emissions by 28% and CH4 uptake by 24% and tended to decrease N2O emissions. Supplemental irrigation increased N2O emissions but had little effect on CO2 emissions and CH4 uptake. Evidently, warming and supplemental irrigation had interactive effects on wheat yield, GHG emissions and GHG emissions intensity. Precision irrigation appears to be a means of simultaneously increasing wheat yield and reducing GHG emissions under warming conditions in semi-arid areas.

Fatty acid biomarkers of dairy fat consumption and incidence of type 2 diabetes : A pooled analysis of prospective cohort studies
Imamura, Fumiaki ; Fretts, Amanda ; Marklund, Matti ; Ardisson Korat, Andres V. ; Yang, Wei Sin ; Lankinen, Maria ; Qureshi, Waqas ; Helmer, Catherine ; Chen, Tzu An ; Wong, Kerry ; Bassett, Julie K. ; Murphy, Rachel ; Tintle, Nathan ; Yu, Chaoyu Ian ; Brouwer, Ingeborg A. ; Chien, Kuo Liong ; Frazier-Wood, Alexis C. ; Gobbo, Liana C. Del; Djoussé, Luc ; Geleijnse, Johanna M. ; Giles, Graham G. ; Goede, Janette de; Gudnason, Vilmundur ; Harris, William S. ; Hodge, Allison ; Hu, Frank ; Koulman, Albert ; Laakso, Markku ; Lind, Lars ; Lin, Hung Ju ; McKnight, Barbara ; Rajaobelina, Kalina ; Risérus, Ulf ; Robinson, Jennifer G. ; Samieri, Cécilia ; Siscovick, David S. ; Soedamah-Muthu, Sabita S. ; Sotoodehnia, Nona ; Sun, Qi ; Tsai, Michael Y. ; Uusitupa, Matti ; Wagenknecht, Lynne E. ; Wareham, Nick J. ; Wu, Jason Hy ; Micha, Renata ; Forouhi, Nita G. ; Lemaitre, Rozenn N. ; Mozaffarian, Dariush - \ 2018
PLOS Medicine 15 (2018)10. - ISSN 1549-1676 - p. e1002670 - e1002670.

BACKGROUND: We aimed to investigate prospective associations of circulating or adipose tissue odd-chain fatty acids 15:0 and 17:0 and trans-palmitoleic acid, t16:1n-7, as potential biomarkers of dairy fat intake, with incident type 2 diabetes (T2D).

METHODS AND FINDINGS: Sixteen prospective cohorts from 12 countries (7 from the United States, 7 from Europe, 1 from Australia, 1 from Taiwan) performed new harmonised individual-level analysis for the prospective associations according to a standardised plan. In total, 63,682 participants with a broad range of baseline ages and BMIs and 15,180 incident cases of T2D over the average of 9 years of follow-up were evaluated. Study-specific results were pooled using inverse-variance-weighted meta-analysis. Prespecified interactions by age, sex, BMI, and race/ethnicity were explored in each cohort and were meta-analysed. Potential heterogeneity by cohort-specific characteristics (regions, lipid compartments used for fatty acid assays) was assessed with metaregression. After adjustment for potential confounders, including measures of adiposity (BMI, waist circumference) and lipogenesis (levels of palmitate, triglycerides), higher levels of 15:0, 17:0, and t16:1n-7 were associated with lower incidence of T2D. In the most adjusted model, the hazard ratio (95% CI) for incident T2D per cohort-specific 10th to 90th percentile range of 15:0 was 0.80 (0.73-0.87); of 17:0, 0.65 (0.59-0.72); of t16:1n7, 0.82 (0.70-0.96); and of their sum, 0.71 (0.63-0.79). In exploratory analyses, similar associations for 15:0, 17:0, and the sum of all three fatty acids were present in both genders but stronger in women than in men (pinteraction < 0.001). Whereas studying associations with biomarkers has several advantages, as limitations, the biomarkers do not distinguish between different food sources of dairy fat (e.g., cheese, yogurt, milk), and residual confounding by unmeasured or imprecisely measured confounders may exist.

CONCLUSIONS: In a large meta-analysis that pooled the findings from 16 prospective cohort studies, higher levels of 15:0, 17:0, and t16:1n-7 were associated with a lower risk of T2D.

Comparison of ecosystem services provided by grasslands with different utilization patterns in China’s Inner Mongolia Autonomous Region
Du, Bingzhen ; Zhen, Lin ; Hu, Yunfeng ; Yan, Huimin ; Groot, Rudolf de; Leemans, Rik - \ 2018
Journal of Geographical Sciences 28 (2018)10. - ISSN 1009-637X - p. 1399 - 1414.
ecosystem services - grasslands utilization pattern - household livelihoods - natural resource management - soil - vegetation

Although several previous studies in Inner Mongolia examined the effects of ecological conservation on the delivery of ecosystem services, they were often limited in scope (few ecosystem services were assessed) and often suffered from confounding by spatial variation. In this study, we examined the impact of conservation measures (changes in grassland utilization patterns) on the provision of selected ecosystem services in three types of grasslands (meadow steppe in Hulun Buir, typical steppe in Xilin Gol, and semi-desert steppe in Ordos) in Inner Mongolia. We examined five utilization patterns: no use (natural grasslands), light use, moderate use, intensive use, and recovery sites (degraded sites protected from further use). Through household surveys and vegetation and soil surveys, we measured the differences in ecosystem services among the different grassland utilization patterns. We also identified spatial factors that confounded the quantification of ecosystem services in different types of grasslands. We found that light use generally provided high levels of ecosystem services in meadow steppe and typical steppe, with the main differences in the supporting ecosystem services. Surprisingly, we found no consistently positive impacts of strict conservation activities across the sites, since the results varied spatially and with respect to differences in the land-use patterns. Our study suggests that appropriate grassland utilization patterns can enhance the supply of ecosystem services and reduce negative effects on both household livelihoods and the environment.

Designing Vulnerable Zones of Nitrogen and Phosphorus Transfers to Control Water Pollution in China
Bai, Zhaohai ; Lu, Jie ; Zhao, Hao ; Velthof, Gerard L. ; Oenema, Oene ; Chadwick, Dave ; Williams, John R. ; Jin, Shuqin ; Liu, Hongbin ; Wang, Mengru ; Strokal, Maryna ; Kroeze, Carolien ; Hu, Chunsheng ; Ma, Lin - \ 2018
Environmental Science and Technology 52 (2018)16. - ISSN 0013-936X - p. 8987 - 8988.
Microscopic Origins of Shear Jamming for 2D Frictional Grains
Wang, Dong ; Ren, Jie ; Dijksman, Joshua A. ; Zheng, Hu ; Behringer, Robert P. - \ 2018
Physical Review Letters 120 (2018)20. - ISSN 0031-9007

Shear jamming (SJ) occurs for frictional granular materials with packing fractions φ in φS<φ<φJ0, when the material is subject to shear strain γ starting from a force-free state. Here, φJμ is the isotropic jamming point for particles with a friction coefficient μ. SJ states have mechanically stable anisotropic force networks, e.g., force chains. Here, we investigate the origins of SJ by considering small-scale structures - trimers and branches - whose response to shear leads to SJ. Trimers are any three grains where the two outer grains contact a center one. Branches occur where three or more quasilinear force chain segments intersect. Certain trimers respond to shear by compressing and bending; bending is a nonlinear symmetry-breaking process that can push particles in the dilation direction faster than the affine dilation. We identify these structures in physical experiments on systems of two-dimensional frictional discs, and verify their role in SJ. Trimer bending and branch creation both increase Z above Ziso≃3 needed for jamming 2D frictional grains, and grow the strong force network, leading to SJ.

The functional oligomeric state of tegument protein GP41 is essential for baculovirus budded virion and occlusion-derived virion assembly
Li, Yimeng ; Shen, Shu ; Hu, Liangbo ; Deng, Fei ; Vlak, Just M. ; Hu, Zhihong ; Wang, Hualin ; Wang, Manli - \ 2018
Journal of Virology 92 (2018)12. - ISSN 0022-538X
Baculovirus - Function - GP41 - Leucine zipper - Oligomerization - Tegument protein - Virion assembly
gp41, one of the baculovirus core genes, encodes the only recognized tegument (O-glycosylated) protein of the occlusion-derived virion (ODV) phenotype so far. A previous study using a temperature-sensitive Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) mutant showed that GP41 plays a crucial role in budded virion (BV) formation. However, the precise function of GP41 in the baculovirus replication cycle remains unclear. In this study, AcMNPV GP41 was found to accumulate around the ring zone (RZ) region within the infected nucleus and finally assembled into both BVs and ODVs. Deletion of gp41 from the AcMNPV genome showed that BVs were no longer formed and ODVs were no longer assembled, suggesting the essential role of this gene in baculovirus virion morphogenesis. In infected cells, besides the 42-kDa monomers, dimers and trimers were detected under nonreducing conditions, whereas only trimeric GP41 forms were selectively incorporated into BVs or ODVs. Mutations of all five cysteines in GP41 individually had minor effects on GP41 oligomer formation, albeit certain mutations impaired infectious BV production, suggesting flexibility in the intermolecular disulfide bonding. Single mutations of key leucines within two predicted leucine zipper-like motifs did not interfere with GP41 oligomerization or BV and ODV formation, but double leucine mutations completely blocked oligomerization of GP41 and progeny BV production. In the latter case, the usual subcellular localization, especially RZ accumulation, of GP41 was abolished. The above findings clearly point out a close correlation between GP41 oligomerization and function and therefore highlight the oligomeric state as the functional form of GP41 in the baculovirus replication cycle.
Regulation of myostatin expression is associated with growth and muscle development in commercial broiler and DMC muscle
Dou, Tengfei ; Li, Zhengtian ; Wang, Kun ; Liu, Lixian ; Rong, Hua ; Xu, Zhiqiang ; Huang, Ying ; Gu, Dahai ; Chen, Xiaobo ; Hu, Wenyuan ; Zhang, Jiarong ; Zhao, Sumei ; Jois, Markandeya ; Li, Qihua ; Ge, Changrong ; Pas, Marinus F.W. te; Jia, Junjing - \ 2018
Molecular Biology Reports 45 (2018)4. - ISSN 0301-4851 - p. 511 - 522.
Commercial broiler chicken - Daweishan mini chicken - Growth rate - mRNA expression - Muscle weight - Myostatin
Myostatin is a negative regulator of skeletal muscle growth. Muscle tissue is the largest tissue in the body and influences body growth. Commercial Avian broiler chickens are selected for high growth rate and muscularity. Daweishan mini chickens are a slow growing small-sized chicken breed. We investigated the relations between muscle (breast and leg) myostatin mRNA expression and body and muscle growth. Twenty chickens per breed were slaughtered at 0, 30, 60, 90, 120, and 150 days of age. Body and muscle weights were higher at all times in Avian chickens. Breast muscle myostatin expression was higher in Avian chickens than in Daweishan mini chickens at day 30. Myostatin expression peaked at day 60 in Daweishan mini chickens and expression remained higher in breast muscle. Daweishan mini chickens myostatin expression correlated positively with carcass weight, breast and leg muscle weight from day 0 to 60, and correlated negatively with body weight from day 90 to 150, while myostatin expression in Avian chickens was negatively correlated with carcass and muscle weight from day 90 to 150. The results suggest that myostatin expression is related to regulation of body growth and muscle development, with two different regulatory mechanisms that switch between days 30 and 60.
Effect of dietary Ca to P ratio and particle size of limestone on growth performance and digesta pH in different intestinal segments in broilers
Hu, Yixin ; Bikker, P. ; Duijster, M. ; Baal, J. van; Hendriks, W.H. ; Krimpen, M.M. van - \ 2018
The group I alphabaculovirus-specific protein, AC5, is a novel component of the occlusion body but is not associated with ODVS or the PIF complex
Wang, Xi ; Chen, Cheng ; Zhang, Nan ; Li, Jiang ; Deng, Fei ; Wang, Hualin ; Vlak, Just M. ; Hu, Zhihong ; Wang, Manli - \ 2018
Journal of General Virology 99 (2018)4. - ISSN 0022-1317 - p. 585 - 595.
Ac5 - Baculovirus - Function - Group I alphabaculovirus - Occlusion body - PIF complex
Autographa californica nucleopolyhedrovirus (AcMNPV) orf5 (ac5) is a group I alphabaculovirus-specific gene of unknown function, although the protein (AC5) was previously reported to be associated with the per os infectivity factor (PIF) complex. The purpose of this study was to study the dynamics of AC5 during AcMNPV infection and to verify whether it is indeed a component of the PIF complex. Transcription and expression analyses suggested that ac5 is a late viral gene. An ac5-deleted recombinant AcMNPV was generated by homologous recombination. A one-step growth curve assay indicated that ac5 was not required for budded virus (BV) production in Sf9 cells. Scanning electron microscopy and transmission electron microscopy demonstrated that the deletion of ac5 did not affect occlusion body (OB) morphology, and nor did it affect the insertion of occlusion-derived virus (ODV) into OBs. Partially denaturing SDS-PAGE and a co-immunoprecipitation assay clearly showed that AC5 was not a component of the PIF complex, while the deletion of ac5 did not affect the formation and presence of the PIF complex. Further analyses showed, however, that AC5 was an OB-specific protein, but it was not detected as a component of BVs or ODVs. Bioassay experiments showed that the oral infectivity of ac5-deleted AcMNPV to third instar Spodoptera exigua larvae was not significantly different from that of the ac5-repaired virus. In conclusion, AC5 is an intrinsic protein of OBs, instead of being a component of the PIF complex, and is not essential for either BV or ODV infection. AC5 is awaiting the assignment of another hitherto unknown function.
RAF2 is a RuBisCO assembly factor in Arabidopsis thaliana
Fristedt, Rikard ; Hu, Chen ; Wheatley, Nicole ; Roy, Laura M. ; Wachter, Rebekka M. ; Savage, Linda ; Harbinson, Jeremy ; Kramer, David M. ; Merchant, Sabeeha S. ; Yeates, Todd ; Croce, Roberta - \ 2018
The Plant Journal 94 (2018)1. - ISSN 0960-7412 - p. 146 - 156.
Abscisic acid - Atg5 g51110 - Chloroplast - RAF2 - RuBisCO - RuBisCO aggregation - RuBisCO assembly factor - SDIRIP1
Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) catalyzes the reaction between gaseous carbon dioxide (CO2) and ribulose-1,5-bisphosphate. Although it is one of the most studied enzymes, the assembly mechanisms of the large hexadecameric RuBisCO is still emerging. In bacteria and in the C4 plant Zea mays, a protein with distant homology to pterin-4α-carbinolamine dehydratase (PCD) has recently been shown to be involved in RuBisCO assembly. However, studies of the homologous PCD-like protein (RAF2, RuBisCO assembly factor 2) in the C3 plant Arabidopsis thaliana (A. thaliana) have so far focused on its role in hormone and stress signaling. We investigated whether A. thalianaRAF2 is also involved in RuBisCO assembly. We localized RAF2 to the soluble chloroplast stroma and demonstrated that raf2 A. thaliana mutant plants display a severe pale green phenotype with reduced levels of stromal RuBisCO. We concluded that the RAF2 protein is probably involved in RuBisCO assembly in the C3 plant A. thaliana.
Modes of selenium occurrence and LCD modeling of selenite desorption/adsorption in soils around the selenium-rich core, Ziyang County, China
Zhang, Yu ; Wu, Siyuan ; Zheng, Hong ; Weng, Liping ; Hu, Yajie ; Ma, Hongwen - \ 2018
Environmental Science and Pollution Research 25 (2018)15. - ISSN 0944-1344 - p. 14521 - 14531.
Desorption/adsorption - High-Se soils - LCD modeling - Modes of selenium occurrence - Selenium-rich core - Ziyang County
Studying the modes of selenium occurrence in high-Se soils and its behaviors can improve understanding and evaluating its cycling, flux, and balance in geo-ecosystems and its influence on health. In this paper, using a modified sequential chemical extraction technique, seven operationally defined selenium fractions and Se valence distribution were determined about five soils in which paddy was planted (W1, W2, W3, W4, W5) and five soils in which maize was planted (H1, H2, H3, H4, H5) around the selenium-rich core, Ziyang County, Shaanxi Province, China. The results show that selenium fractions in the soils mainly include sulfide/selenide and base-soluble Se, and ligand-exchangeable Se is also high for five soils in which paddy was planted. For water-soluble Se, Se (IV) is main Se valence and almost no Se (VI) was determined about five soils in which paddy was planted, while almost 1:1 of Se (IV) and Se (VI) coexist about five soils in which maize was planted. For exchangeable Se, similar results were found. For the first time, two typical high-Se soils (W1 soil and H1 soil) were chosen to measure the pH-dependent solid-solution distribution of selenite in the pH range 3–9, and the results were explained using LCD (ligand and charge distribution) adsorption modeling. The desorbed selenite concentrations from the two soils are in general underestimated by the model due to a comparable binding affinity of phosphate and selenite on goethite and much lower amount of total selenite than total reactively adsorbed phosphate. The pH dependency of adsorption of selenite added to the soil can be successfully described with the LCD model for W1 soil. Whereas considering the influence of Al-oxides, by lowering selenite adsorption affinity constant K of Se adsorption on goethite by 16 times, the LCD model can describe the adsorption much better. The results can help to understand selenium cycling, flux, and balance in typical high-Se soils.
Enzyme activities at different stages of plant biomass decomposition in three species of fungusgrowing termites
Costa, Rafael R. da; Hu, Haofu ; Pilgaard, Bo ; Sabine, Sabine M. ; Schückel, Julia ; Pedersen, Kristine S.K. ; Kračun, Stjepan K. ; Busk, Peter K. ; Harholt, Jesper ; Sapountzis, Panagiotis ; Lange, Lene ; Aanen, Duur K. ; Poulsen, Michael - \ 2018
Applied and Environmental Microbiology 84 (2018)5. - ISSN 0099-2240
AZCL - Chromogenic substrates - HPLC - Macrotermes - Odontotermes - Peptide pattern recognition - Plant substrate - RNA-seq - Symbiosis - Termitomyces
Fungus-growing termites rely on mutualistic fungi of the genus Termitomyces and gut microbes for plant biomass degradation. Due to a certain degree of symbiont complementarity, this tripartite symbiosis has evolved as a complex bioreactor, enabling decomposition of nearly any plant polymer, likely contributing to the success of the termites as one of the main plant decomposers in the Old World. In this study, we evaluated which plant polymers are decomposed and which enzymes are active during the decomposition process in two major genera of fungus-growing termites. We found a diversity of active enzymes at different stages of decomposition and a consistent decrease in plant components during the decomposition process. Furthermore, our findings are consistent with the hypothesis that termites transport enzymes from the older mature parts of the fungus comb through young worker guts to freshly inoculated plant substrate. However, preliminary fungal RNA sequencing (RNA-seq) analyses suggest that this likely transport is supplemented with enzymes produced in situ. Our findings support that the maintenance of an external fungus comb, inoculated with an optimal mixture of plant material, fungal spores, and enzymes, is likely the key to the extraordinarily efficient plant decomposition in fungus-growing termites.
The Impact of Ecological Construction Programs on Grassland Conservation in Inner Mongolia, China
Liu, Min ; Dries, Liesbeth ; Heijman, Wim ; Huang, Jikun ; Zhu, Xueqin ; Hu, Yuanning ; Chen, Haibin - \ 2018
Land Degradation and Development 29 (2018)2. - ISSN 1085-3278 - p. 326 - 336.
Ecological Construction Programs - fixed effects model - grassland degradation - Inner Mongolia - NDVI
A series of Ecological Construction Programs have been initiated to protect the condition of grasslands in China during recent decades. However, grassland degradation is still severe, and conditions have not been restored as intended. This paper aims to empirically examine the effectiveness of these programs for protecting the grassland condition in the extensive pastoral areas of China. We focus on one major program that has been implemented widely on the grasslands, the Subsidy and Incentive System for Grassland Conservation (SISGC). The normalized difference vegetation index, measured with remote sensing technology, is used to quantify the grassland condition between 2001 and 2014. With data from 54 counties in the pastoral areas of Inner Mongolia, we estimate the impact of SISGC on the grassland condition. A fixed effects model is employed to control for livestock production, climate, time trends, and time-invariant heterogeneity between counties. The model results provide quantitative evidence that the condition of the grasslands has improved significantly because of SISGC; but that the effectiveness of SISGC was offset to some extent by other socio-economic and climate factors, such as increased producer prices and high temperature. This may explain why the actual grassland degradation has not been prevented as effectively as was expected. In addition, the impact of SISGC was stronger in counties with worse initial grassland condition. Furthermore, the effects of producer prices and climate changes were also more pronounced in these counties.
Global environmental costs of China's thirst for milk
Bai, Zhaohai ; Lee, Michael R.F. ; Ma, Lin ; Ledgard, Stewart ; Velthof, Gerard L. ; Ma, Wenqi ; Guo, Mengchu ; Zhao, Zhanqing ; Wei, Sha ; Li, Shengli ; Liu, Xia ; Havlík, Petr ; Luo, Jiafa ; Hu, Chunsheng ; Zhang, Fusuo - \ 2018
Global Change Biology 24 (2018)5. - ISSN 1354-1013 - p. 2198 - 2211.
Cattle feed - Greenhouse gas - Land use, nitrogen losses - Milk trade - Shared socio-economic pathways scenarios
China has an ever-increasing thirst for milk, with a predicted 3.2-fold increase in demand by 2050 compared to the production level in 2010. What are the environmental implications of meeting this demand, and what is the preferred pathway? We addressed these questions by using a nexus approach, to examine the interdependencies of increasing milk consumption in China by 2050 and its global impacts, under different scenarios of domestic milk production and importation. Meeting China's milk demand in a business as usual scenario will increase global dairy-related (China and the leading milk exporting regions) greenhouse gas (GHG) emissions by 35% (from 565 to 764 Tg CO 2eq ) and land use for dairy feed production by 32% (from 84 to 111 million ha) compared to 2010, while reactive nitrogen losses from the dairy sector will increase by 48% (from 3.6 to 5.4 Tg nitrogen). Producing all additional milk in China with current technology will greatly increase animal feed import; from 1.9 to 8.5 Tg for concentrates and from 1.0 to 6.2 Tg for forage (alfalfa). In addition, it will increase domestic dairy related GHG emissions by 2.2 times compared to 2010 levels. Importing the extra milk will transfer the environmental burden from China to milk exporting countries; current dairy exporting countries may be unable to produce all additional milk due to physical limitations or environmental preferences/legislation. For example, the farmland area for cattle-feed production in New Zealand would have to increase by more than 57% (1.3 million ha) and that in Europe by more than 39% (15 million ha), while GHG emissions and nitrogen losses would increase roughly proportionally with the increase of farmland in both regions. We propose that a more sustainable dairy future will rely on high milk demanding regions (such as China) improving their domestic milk and feed production efficiencies up to the level of leading milk producing countries. This will decrease the global dairy related GHG emissions and land use by 12% (90 Tg CO 2eq reduction) and 30% (34 million ha land reduction) compared to the business as usual scenario, respectively. However, this still represents an increase in total GHG emissions of 19% whereas land use will decrease by 8% when compared with 2010 levels, respectively.
An overview of microplastic and nanoplastic pollution in agroecosystems
Ng, Ee Ling ; Huerta Lwanga, Esperanza ; Eldridge, Simon M. ; Johnston, Priscilla ; Hu, Hang Wei ; Geissen, Violette ; Chen, Deli - \ 2018
Science of the Total Environment 627 (2018). - ISSN 0048-9697 - p. 1377 - 1388.
Ecotoxicology - Plant response - Plastic degradation - Soil food web - Soils
Microplastics and nanoplastics are emerging pollutants of global importance. They are small enough to be ingested by a wide range of organisms and at nano-scale, they may cross some biological barriers. However, our understanding of their ecological impact on the terrestrial environment is limited. Plastic particle loading in agroecosystems could be high due to inputs of some recycled organic waste and plastic film mulching, so it is vital that we develop a greater understanding of any potentially harmful or adverse impacts of these pollutants to agroecosystems. In this article, we discuss the sources of plastic particles in agroecosystems, the mechanisms, constraints and dynamic behaviour of plastic during aging on land, and explore the responses of soil organisms and plants at different levels of biological organisation to plastic particles of micro and nano-scale. Based on limited evidence at this point and understanding that the lack of evidence of ecological impact from microplastic and nanoplastic in agroecosystems does not equate to the evidence of absence, we propose considerations for addressing the gaps in knowledge so that we can adequately safeguard world food supply.
Developing a water and nitrogen management model for greenhouse vegetable production in China : Sensitivity analysis and evaluation
Liang, Hao ; Hu, Kelin ; Batchelor, William D. ; Qin, Wei ; Li, Baoguo - \ 2018
Ecological Modelling 367 (2018). - ISSN 0304-3800 - p. 24 - 33.
Auto-calibration - Greenhouse vegetable - Sensitivity analysis - Water and nitrogen management - WHCNS-Veg model
Excessive water and fertilizer inputs have led to a series of environmental problems in vegetable production areas in China. Identifying the fates of water and nutrients is crucial to develop best management strategies in intensive vegetable production systems. The objectives of this study were to (i) develop a scientific water and nitrogen (N) management tool for intensive greenhouse vegetable production in China, and (ii) evaluate the model performance in the simulating the fate of water and N, and vegetable growth under different water and N management practices in China. A vegetable growth component was added to the field soil-crop system model WHCNS (soil Water Heat Carbon Nitrogen Simulator), named WHCNS_Veg. Parameters for the model were estimated and a sensitivity analysis was conducted by coupling the model with the model-independent parameter estimation program (PEST). Data used to test the model came from two years of cucumber and tomato experiments with various water and N combinations in Shandong province, China. The results of sensitivity analysis showed that the soil hydraulic parameters and vegetable genetic parameters had a relatively higher sensitivity compared with those of N transformation parameters. The saturated soil water content had the highest sensitivity among soil hydraulic parameters, and the total available accumulated temperature, crop coefficient and maximum root depth had higher sensitivity for both vegetable crops. Among the N transformation parameters, the parameters related to nitrification had the highest sensitivity. The automatic optimization algorithm performed well in adjusting soil hydraulic parameters, vegetable genetic parameters and N transformation parameters. The normalized root mean square error for soil water content, soil nitrate concentration, marketable fresh yield and vegetable N uptake were 5.7%, 28.0%, 2.7% and 8.3%, respectively, and indices of agreement were 0.727, 0.730, 0.997 and 0.832, respectively. The results indicated that the WHCNS_Veg model has great potential to simulate and analyze water and N fates, and vegetable growth for the intensive greenhouse vegetable production in China.
Triclosan-induced transcriptional and biochemical alterations in the freshwater green algae Chlamydomonas reinhardtii
Pan, Chang Gui ; Peng, Feng-Jiao ; Shi, Wen Jun ; Hu, Li Xin ; Wei, Xiao Dong ; Ying, Guang Guo - \ 2018
Ecotoxicology and Environmental Safety 148 (2018). - ISSN 0147-6513 - p. 393 - 401.
Biochemical alteration - Chlamydomonas reinhardtii - Gene expression - Growth - Toxicity - Triclosan

Triclosan (TCS) is an antibacterial and antifungal agent widely used in personal care products (PCPs). We investigated the effects of TCS (20 μg/L, 100 μg/L and 500 μg/L) on Chlamydomonas reinhardtii by measuring the algal growth, chlorophyll content, lipid peroxidation, and transcription of the antioxidant-related genes (superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), glutathione S-transferase (GST), plastid terminal oxidase 2 (PTOX) and thioredoxin (TRX)) as well as biochemical alterations. The results showed significant dose-related effects of TCS on the algal species in terms of growth and chlorophyll content. Malondialdehyde (MDA) increased with increasing TCS concentrations and showed significant difference between the treatment of 405.3 μg/L TCS and control group. Transcription analysis revealed that the expression of SOD mRNA was most sensitive to TCS among the selected genes. In addition, Fourier-transform infrared spectroscopy showed time- and concentration-specific biochemical responses in C. reinhardtii when exposed to TCS. The biochemical alterations associated with different doses of TCS were mainly attributed to structural changes associated with lipid, protein, nucleic acid and carbohydrate. The findings from this study reveal that TCS in the aquatic environment may affect algal growth, chlorophyll synthesis, oxidative stress responses and cause biochemical alterations. This study provided important information to achieve a better understanding of the toxic mechanism of triclosan on algae Chlamydomonas reinhardtii.

More money, better performance? The effects of student loans and need-based grants in China's higher education
Huang, Wei ; Li, Fan ; Liao, Xiaowei ; Hu, Pingping - \ 2018
China Economic Review 51 (2018). - ISSN 1043-951X - p. 208 - 227.
China - Financial aid - Higher education - Need-based grants - Student achievement - Student loans

The goal of this study is to examine the effect of student loans and need-based grants on financially disadvantaged student academic performance in China's higher education. We used a large sampled data from 101 universities to conduct our study. By employing different matching methods, we found that receiving a student loan did not improve student academic performance, but slightly increased students' likelihood of doing a part-time job. Likewise, receiving a need-based grant had no significant effect on student academic performance. We argue that current financial aid programs do not yield any measurable improvement on student performance. Reform and more rigorous evaluations are needed to design an effective financial aid program to promote the development of higher education in China.

Temperature: crucial factor in feather processing
Goerner-Hu, X. ; Schneider, O. ; Scott, E.L. ; Bitter, J.H. - \ 2017
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