Zhao F.,Chinese Academy of Agricultural Sciences |
Zhao F.,Shanxi Academy of Agricultural Sciences |
Zhang W.,Chinese Academy of Agricultural Sciences |
Hoffmann A.A.,University of Melbourne |
Ma C.-S.,Chinese Academy of Agricultural Sciences
Journal of Animal Ecology | Year: 2014
Summary: An asymmetric increase in night-time temperatures (NTs) on hot days is one of the main features of global climate change. But the biological effects of an increased night-time temperature combined with high daytime temperature are unclear. We used six thermal regimens to simulate NTs on hot days and investigated the effects of night warming on life-history traits of the English grain aphid Sitobion avenae. Experimental temperatures fluctuated in continuous diurnal cycles, increasing from 27°C to a maximum 35°C and then declining to 27°C gradually before further dropping to different minima (13, 16, 19, 21, 23 or 25°C) representing NTs. When compared to expectations based on constant temperatures, night warming raised the optimum temperature for development by 3°C, in contrast to results from experiments where temperature variability was altered symmetrically or in a parallel manner. Night warming also reduced aphid survival under heat from 75% to 37% and depressed adult performance by up to 50%. Overall, night warming exacerbated the detrimental effects of hot days on the intrinsic rate of population increase, which was predicted to drop by 30% when night-time minimum temperatures exceeded 20°C. Our novel findings on development challenge the 'Kaufmann effect', suggesting this is inapplicable to night warming likely to be encountered in nature. Although many average temperature models predict increasing pest outbreaks, our results suggest that outbreaks of some species might decrease due to the effects of night warming on population dynamics. Night warming often occurs in hot days under climate change. Here the authors investigate life-history traits of aphids at six night-time temperatures combined with a high daytime temperature regimen. Night warming raises optimum temperature for development which challenges the 'Kaufmann effect' and reduces nymphal survival unexpectedly. © 2013 The Authors.
Li L.,Copenhagen University |
Li L.,Shanxi Academy of Agricultural Sciences |
Holm P.E.,Copenhagen University |
Marcussen H.,Copenhagen University |
Bruun Hansen H.C.,Copenhagen University
Environmental Pollution | Year: 2014
We studied the bonding and release kinetics of Cd, Cu and Pb from different soils in the older metropolitan area of Copenhagen. Total Cd, Cu and Pb concentrations were elevated 5-27 times in the urban soils compared to an agricultural reference soil, with Cd and Pb in mainly mobilisable pools and Cu in strongly bound pools. The soils were subjected to accelerated leaching studies in Ca(NO3)2 or HNO3 solutions resulting in release up to 78, 18 and 15% of total Cd, Cu and Pb soil concentrations over a period of 15 weeks. The relative initial Cd and Pb release rates increased 10 fold when pH decreased 2 and 3 units, respectively, while increases in Cu release rates were only seen at pH below 4. The total leachable Cu and Pb pools were higher in urban soils compared the agricultural reference soil but not for Cd. © 2014 Elsevier Ltd. All rights reserved.
Zhang L.,Shanxi University |
Liu R.,Cornell University |
Niu W.,Shanxi Academy of Agricultural Sciences
PLoS ONE | Year: 2014
The phytochemical content, antioxidant activity and antiproliferative properties of three diverse varieties of proso millet are reported. The free phenolic content ranged from 27.48 (Gumi 20) to 151.14 (Mi2504-6) mg gallic acid equiv/100 g DW. The bound phenolic content ranged from 55.95 (Gumi20) to 305.81 (Mi2504-6) mg gallic acid equiv/100 g DW. The percentage contribution of bound phenolic to the total phenolic content of genotype samples analyzed ranged between 62.08% and 67.05%. Ferulic acid and chlorogenic acid are the predominant phenolic acid found in bound fraction. Caffeic acid and p-coumaric acid were also detected. Syringic acid was detected only in the free fraction. The antioxidant activity was assessed using the hydrophilic peroxyl radical scavenging capacity (PSC) assay. The PSC antioxidant activity of the free fraction ranged from 57.68 (Mi2504-6) to 147.32 (Gumi20) μmol of vitamin C equiv/100 g DW. The PSC antioxidant activity of the bound fraction ranged from 95.38 (Mizao 52) to 136.48 (Gumi 20) μmol of vitamin C equiv/100 g DW. The cellular antioxidant activity (CAA) of the extract was assessed using the HepG2 model. CAA value ranged from 2.51 to 6.10 μmol equiv quercetin/100 g DW. Antiproliferative activities were also studied in vitro against MDA human breast cancer and HepG2 human liver cancer cells. Results exhibited a differential and possible selective antiproliferative property of the proso millet. These results may be used to direct the consumption of proso millet with improved health properties. © 2014 Zhang et al.
Shanxi Academy of Agricultural Sciences | Date: 2013-04-15
Cui Z.,China Agricultural University |
Yue S.,China Agricultural University |
Wang G.,China Agricultural University |
Meng Q.,China Agricultural University |
And 6 more authors.
Global Change Biology | Year: 2013
Although the goal of doubling food demand while simultaneously reducing agricultural environmental damage has become widely accepted, the dominant agricultural paradigm still considers high yields and reduced greenhouse gas (GHG) intensity to be in conflict with one another. Here, we achieved an increase in maize yield of 70% in on-farm experiments by closing the yield gap and evaluated the trade-off between grain yield, nitrogen (N) fertilizer use, and GHG emissions. Based on two groups of N application experiments in six locations for 16 on-farm site-years, an integrated soil-crop system (HY) approach achieved 93% of the yield potential and averaged 14.8 Mg ha-1 maize grain yield at 15.5% moisture. This is 70% higher than current crop (CC) management. More importantly, the optimal N rate for the HY system was 250 kg N ha-1, which is only 38% more N fertilizer input than that applied in the CC system. Both the N2O emission intensity and GHG intensity increased exponentially as the N application rate increased, and the response curve for the CC system was always higher than that for the HY system. Although the N application rate increased by 38%, N2O emission intensity and the GHG intensity of the HY system were reduced by 12% and 19%, respectively. These on-farm observations indicate that closing the yield gap alongside efficient N management should therefore be prominent among a portfolio of strategies to meet food demand while reducing GHG intensity at the same time. © 2013 John Wiley & Sons Ltd.