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Streams are regionally important sources of CH4 to the atmosphere, but the temporal variability in and control on CH4 concentrations and emissions are not well understood. Especially, lack of long-term data hampers our ability to predict CH4 emissions from streams. Here, we present a seven-year data set of biweekly CH4 concentration and underlying potential drivers from two adjacent small German streams with contrasting riparian area characteristics. Over the seven-year study period, mean CH4 concentration and emissionswere 0.20 and 0.07 μmol L–1 and 2.01 and 0.84 mmol m–2 d–1 for the two streams, respectively. Our findings suggest that the combination of seasonality and topography ultimately shaped the considerable temporal variations of CH4. CH4 oxidation and production in the streams were probably of minor importance. Instead, fluctuations in CH4 concentrations likely reflected temporal pattern of CH4 input from soils of the riparian zone with larger CH4 variations in the stream with more riparian lands. Structural equation modeling revealed DOC and nitrate as important predictors of CH4 concentration. However, we did not identify predictors of the considerable short-term variability, nor the explicit pathways of CH4 delivery to streams. The discrepancy of the CH4 flux between streams was likely triggered by different connectivity to riparian soils with higher CH4 emissions in the hydrologically more connected stream. Inter-annual comparison showed that changing hydrologic conditions, rather than warming, may impact future CH4 emissions from temperate streams. We predict higher CH4 emissions occur in wetter years in streams with close connectivity to riparian soils.
Peifang Leng; Norbert Kamjunke; Fadong Li; Matthias Koschorreck. Temporal Patterns of Methane Emissions From Two Streams With Different Riparian Connectivity. Journal of Geophysical Research: Biogeosciences 2021, 126, 1 .
AMA StylePeifang Leng, Norbert Kamjunke, Fadong Li, Matthias Koschorreck. Temporal Patterns of Methane Emissions From Two Streams With Different Riparian Connectivity. Journal of Geophysical Research: Biogeosciences. 2021; 126 (8):1.
Chicago/Turabian StylePeifang Leng; Norbert Kamjunke; Fadong Li; Matthias Koschorreck. 2021. "Temporal Patterns of Methane Emissions From Two Streams With Different Riparian Connectivity." Journal of Geophysical Research: Biogeosciences 126, no. 8: 1.
Agriculture is an important N2O emissions source. Water cycle and nitrogen cycles have important effects on N2O in farmland ecosystems. The changes in the groundwater table can lead to changes in farmland the water and nitrogen cycle processes. However, how this such changes will affect N2O emissions from farmland remains unclear. In this study, a two-year volume lysimeter experiment (2019–2020), including four controlled groundwater tables (i.e., 40, 70, 110, and 150 cm), was performed to monitor the variations in the NO3− and N2O concentrations in shallow groundwater as well as the direct N2O emissions due to surface soil and groundwater evaporation. Our results showed that N2O emissions during fertilization accounted for 80%–90% of the total N2O emissions throughout the maize growing period. Direct N2O emissions increase with the increase in the groundwater table. The total N2O emissions in 2020 were 96.44, 9.75, 6.46, and 6.22 kg ha−1 y−1 at a groundwater table of 40, 70, 110, and 150 cm, respectively. The high water-filled pore space (WFPS) value resulting from the elevated groundwater table increased the groundwater–atmosphere connectivity, leading to significantly increased N2O emissions after fertilization. Increased precipitation (454.90 mm in 2020 vs. 180.30 mm in 2019) accelerated the hydrological processes in agroecology, reducing the retention time of N2O (6 weeks in 2020 vs. 7.5 weeks in 2019) and NO3− (6.75 weeks in 2020 vs. 7.25 weeks in 2019) in shallow groundwater. Studying the influence of shallow groundwater tables on direct N2O emissions will provide insights into the interaction between the water and nitrogen cycles in agroecosystems. The results of this study suggest that direct N2O emissions can be effectively reduced by controlling the groundwater table in agricultural fields in the North China Plain.
Zhao Li; Qiuying Zhang; Yunfeng Qiao; Peifang Leng; Qian Zhang; Kun Du; Chao Tian; Xiaoyan Li; Gang Chen; Fadong Li. Influence of the shallow groundwater table on the groundwater N2O and direct N2O emissions in summer maize field in the North China Plain. Science of The Total Environment 2021, 799, 149495 .
AMA StyleZhao Li, Qiuying Zhang, Yunfeng Qiao, Peifang Leng, Qian Zhang, Kun Du, Chao Tian, Xiaoyan Li, Gang Chen, Fadong Li. Influence of the shallow groundwater table on the groundwater N2O and direct N2O emissions in summer maize field in the North China Plain. Science of The Total Environment. 2021; 799 ():149495.
Chicago/Turabian StyleZhao Li; Qiuying Zhang; Yunfeng Qiao; Peifang Leng; Qian Zhang; Kun Du; Chao Tian; Xiaoyan Li; Gang Chen; Fadong Li. 2021. "Influence of the shallow groundwater table on the groundwater N2O and direct N2O emissions in summer maize field in the North China Plain." Science of The Total Environment 799, no. : 149495.
Soil water content (SWC) is an important factor restricting crop growth and yield in cropland ecosystems. The observation and simulation of soil moisture contribute greatly to improving water-use efficiency and crop yield. This study was conducted at the Shandong Yucheng Agro-ecosystem National Observation and Research Station in the North China Plain. The study period was across the winter wheat (Triticum aestivum L.) growth stages from 2017 to 2019. A cosmic-ray neutron probe was used to monitor the continuous daily SWC. Furthermore, the crop leaf area index (LAI), yield, and aboveground biomass of winter wheat were determined. The root zone quality model 2 (RZWQM2) was used to simulate and validate the SWC, crop LAI, yield, and aboveground biomass. The results showed that the simulation errors of SWC were minute across the wheat growth stages and mature stages in 2017–2019. The root mean square error (RMSE) and relative root mean square error (RRMSE) of the SWC simulation at the jointing stage of winter wheat were 0.0296 and 0.1605 in 2017–2018, and 0.0265 and 0.1480 in 2018–2019, respectively. During the rain-affected days, the RMSE (0.0253) and RRMSE (0.0980) for 2017–2018 were significantly lower than those of 2018–2019 (0.0301 and 0.1458, respectively), indicating that rain events decreased the model accuracy in the dry years compared to the wet years. The simulated LAIs were significantly higher than the measured values. The simulated yield value of winter wheat was 5.61% lower and 3.92% higher than the measured yield in 2017–2018 and in 2018–2019, respectively. The simulated value of aboveground biomass was significantly (45.48%) lower than the measured value in 2017–2018. This study showed that, compared with the dry and cold wheat growth period of 2018–2019, the higher precipitation and temperature in 2017–2018 led to a poorer simulation of SWC and crop-growth components. This study indicated that annual abnormal rainfall and temperature had a significant influence on the simulation of SWC and wheat growth, especially under intensive climate-change stress conditions.
Kun Du; Yunfeng Qiao; Qiuying Zhang; Fadong Li; Qi Li; Shanbao Liu; Chao Tian. Modeling Soil Water Content and Crop-Growth Metrics in a Wheat Field in the North China Plain Using RZWQM2. Agronomy 2021, 11, 1245 .
AMA StyleKun Du, Yunfeng Qiao, Qiuying Zhang, Fadong Li, Qi Li, Shanbao Liu, Chao Tian. Modeling Soil Water Content and Crop-Growth Metrics in a Wheat Field in the North China Plain Using RZWQM2. Agronomy. 2021; 11 (6):1245.
Chicago/Turabian StyleKun Du; Yunfeng Qiao; Qiuying Zhang; Fadong Li; Qi Li; Shanbao Liu; Chao Tian. 2021. "Modeling Soil Water Content and Crop-Growth Metrics in a Wheat Field in the North China Plain Using RZWQM2." Agronomy 11, no. 6: 1245.
Water is the key limiting factor in socioeconomic and ecological development, but it is adversely affected by climate change. The novel virtual water (VW) concept and water, energy, food, biodiversity, and human health (WEFBH) nexus approach are powerful tools to assess the sustainability of a region through the lens of climate change. Climate change-related challenges and water are complex and intertwined. This paper analyzed the significant WEFBH sectors using the multicriteria decision-making (MCDM) and analytic hierarchy process (AHP) model. The AHP model demonstrated quantitative relationships among WEFBH nexus sustainability indicators in the Greater Horn of Africa countries. Besides, the net VW imports and water footprints of major staple crops were assessed. The composite WEFBH nexus indices varied from 0.10 to 0.14. The water footprint of crops is increasing period by period. The results also revealed that most countries in the study area are facing WEFBH domains unsustainability due to weak planning or improper management strategies. The strong policy constancy among the WEFBH sector is vital for dissociating the high-water consumption from crop production, energy, environmental, and human health system. Thus, this study enhances insights into the interdependencies, interconnectedness, and interactions of sectors thereby strengthening the coordination, complementarities, and synergies among them. To attain sustainable development, we urgently call all public and private entities to value the amount of VW used in their daily activities and design better policies on the complex WEFBH nexus and future climate change.
Hubert Hirwa; Qiuying Zhang; Yunfeng Qiao; Yu Peng; Peifang Leng; Chao Tian; Sayidjakhon Khasanov; Fadong Li; Alphonse Kayiranga; Fabien Muhirwa; Auguste Itangishaka; Gabriel Habiyaremye; Jean Ngamije. Insights on Water and Climate Change in the Greater Horn of Africa: Connecting Virtual Water and Water-Energy-Food-Biodiversity-Health Nexus. Sustainability 2021, 13, 6483 .
AMA StyleHubert Hirwa, Qiuying Zhang, Yunfeng Qiao, Yu Peng, Peifang Leng, Chao Tian, Sayidjakhon Khasanov, Fadong Li, Alphonse Kayiranga, Fabien Muhirwa, Auguste Itangishaka, Gabriel Habiyaremye, Jean Ngamije. Insights on Water and Climate Change in the Greater Horn of Africa: Connecting Virtual Water and Water-Energy-Food-Biodiversity-Health Nexus. Sustainability. 2021; 13 (11):6483.
Chicago/Turabian StyleHubert Hirwa; Qiuying Zhang; Yunfeng Qiao; Yu Peng; Peifang Leng; Chao Tian; Sayidjakhon Khasanov; Fadong Li; Alphonse Kayiranga; Fabien Muhirwa; Auguste Itangishaka; Gabriel Habiyaremye; Jean Ngamije. 2021. "Insights on Water and Climate Change in the Greater Horn of Africa: Connecting Virtual Water and Water-Energy-Food-Biodiversity-Health Nexus." Sustainability 13, no. 11: 6483.
Given the impact of COVID-19 and the desert locust plague, the Ethiopian food security issue has once again received widespread attention. Its food crisis requires comprehensive and systematic research to achieve the United Nations Sustainable Development Goal of zero hunger. This review discusses the current situation and the causes of food security in Ethiopia. We focus on the challenges in the food security assessment field. The article lists seven typical causes of food insecurity and three roots of food security in Ethiopia. Long-term food security assessment and a comprehensive understanding and manageability for food security causes are considered as the main existing research challenges. Climate-resilient management, water management, and long-term ecosystem network monitoring and data mining are suggested as potential roadmap for future research.
Yu Peng; Hubert Hirwa; Qiuying Zhang; Guoqin Wang; Fadong Li. Dryland Food Security in Ethiopia: Current Status, Opportunities, and a Roadmap for the Future. Sustainability 2021, 13, 6503 .
AMA StyleYu Peng, Hubert Hirwa, Qiuying Zhang, Guoqin Wang, Fadong Li. Dryland Food Security in Ethiopia: Current Status, Opportunities, and a Roadmap for the Future. Sustainability. 2021; 13 (11):6503.
Chicago/Turabian StyleYu Peng; Hubert Hirwa; Qiuying Zhang; Guoqin Wang; Fadong Li. 2021. "Dryland Food Security in Ethiopia: Current Status, Opportunities, and a Roadmap for the Future." Sustainability 13, no. 11: 6503.
River ecosystems are under increasing stress in the background of global change and ever-growing anthropogenic impacts in Central Asia. However, available water quality data in this region are insufficient for a reliable assessment of the current status, which come as no surprise that the limited knowledge of regulating processes for further prediction of solute variations hinders the development of sustainable management strategies. Here, we analyzed a dataset of various water quality variables from two sampling campaigns in 2019 in the catchments of two major rivers in Central Asia—the Amu Darya and Syr Darya Rivers. Our results suggested high spatial heterogeneity of salinity and major ion components along the longitudinal directions in both river catchments, pointing to an increasing influence of human activities toward downstream areas. We linked the modeling outputs from the global nutrient model (IMAGE-GNM) to riverine nutrients to elucidate the effect of different natural and anthropogenic sources in dictating the longitudinal variations of the riverine nutrient concentrations (N and P). Diffuse nutrient loadings dominated the export flux into the rivers, whereas leaching and surface runoff constituted the major fractions for N and P, respectively. Discharge of agricultural irrigation water into the rivers was the major cause of the increases in nutrients and salinity. Given that the conditions in Central Asia are highly susceptible to climate change, our findings call for more efforts to establish holistic management of water quality.
Peifang Leng; Qiuying Zhang; Fadong Li; Rashid Kulmatov; Guoqin Wang; Yunfeng Qiao; Jianqi Wang; Yu Peng; Chao Tian; Nong Zhu; Hubert Hirwa; Sayidjakhon Khasanov. Agricultural impacts drive longitudinal variations of riverine water quality of the Aral Sea basin (Amu Darya and Syr Darya Rivers), Central Asia. Environmental Pollution 2021, 284, 117405 .
AMA StylePeifang Leng, Qiuying Zhang, Fadong Li, Rashid Kulmatov, Guoqin Wang, Yunfeng Qiao, Jianqi Wang, Yu Peng, Chao Tian, Nong Zhu, Hubert Hirwa, Sayidjakhon Khasanov. Agricultural impacts drive longitudinal variations of riverine water quality of the Aral Sea basin (Amu Darya and Syr Darya Rivers), Central Asia. Environmental Pollution. 2021; 284 ():117405.
Chicago/Turabian StylePeifang Leng; Qiuying Zhang; Fadong Li; Rashid Kulmatov; Guoqin Wang; Yunfeng Qiao; Jianqi Wang; Yu Peng; Chao Tian; Nong Zhu; Hubert Hirwa; Sayidjakhon Khasanov. 2021. "Agricultural impacts drive longitudinal variations of riverine water quality of the Aral Sea basin (Amu Darya and Syr Darya Rivers), Central Asia." Environmental Pollution 284, no. : 117405.
Choosing an appropriate wavelength range, extracting optimal wavelength variables, and selecting suitable statistical analysis methods are of great importance for improving the prediction accuracy of soil nitrogen (N) with near-infrared (NIR) spectroscopy. In this study, the prediction performances of two different wavelength ranges, a short wavelength range (SWR) of 900–1,700 nm and a full wavelength range (FWR) of 900–2,500 nm, are evaluated for the measurement of soil N content. Spectral scanning is performed on wet and dry-sieve soil samples to assess the effect of moisture on the prediction performance of soil N. Two calibration methods, a commonly used linear partial least squares regression (PLSR) and a nonlinear back propagation neural network (BPNN), are used. To understand if it is possible to reduce the number of wavelength variables without decreasing prediction accuracy, we introduce a successive projection algorithm (SPA) to extract wavelength variables that are minimally redundant. The results show that models developed within FWR outperform those developed within SWR, regardless of wet or dry soil conditions, which can be attributed to the presence of more spectral information related to soil N in FWR. Compared with PLSR, BPNN is a better choice for predicting soil N, because BPNN models provide higher accuracy. The best prediction performance is achieved by BPNN method in FWR using a SPA with Rp2 = 0.93, RMSEP = 0.0297% and RPD = 4.00 of wet soil samples, and Rp2 = 0.99, RMSEP = 0.0132% and RPD = 8.76 of dry soil samples. Additionally, we demonstrate that using the SPA algorithm significantly reduces the number of wavelength variables while maintaining high prediction accuracy. The characteristic wavelengths selected by the SPA algorithm follow the principle of material spectral absorption. It is worth noting that dry soil conditions lead to superior performance over wet soil conditions for the measurement of soil N, which can be attributed to the removal effect of moisture content from the wavelength region and the utilization of important absorption features. However, even under wet soil conditions, the simplified calibration models based on selected SPA variables obtain excellent quantitative prediction using the BPNN method in the SWR range, with Rp2 = 0.91, RMSEP = 0.0305%, and RPD = 3.47. It is important to expand large-scale detection applications for the measurement of soil N.
Qinqin Wang; Hao Zhang; Fadong Li; Congke Gu; Yunfeng Qiao; Siyuan Huang. Assessment of calibration methods for nitrogen estimation in wet and dry soil samples with different wavelength ranges using near-infrared spectroscopy. Computers and Electronics in Agriculture 2021, 186, 106181 .
AMA StyleQinqin Wang, Hao Zhang, Fadong Li, Congke Gu, Yunfeng Qiao, Siyuan Huang. Assessment of calibration methods for nitrogen estimation in wet and dry soil samples with different wavelength ranges using near-infrared spectroscopy. Computers and Electronics in Agriculture. 2021; 186 ():106181.
Chicago/Turabian StyleQinqin Wang; Hao Zhang; Fadong Li; Congke Gu; Yunfeng Qiao; Siyuan Huang. 2021. "Assessment of calibration methods for nitrogen estimation in wet and dry soil samples with different wavelength ranges using near-infrared spectroscopy." Computers and Electronics in Agriculture 186, no. : 106181.
Arid areas are widespread globally and support a third of the world's population's livelihoods. The increasing population, urbanization, land-use changes, and the climate significantly affect coupled natural and human systems and threaten environments and socio-ecological land systems. The degradation of drylands poses a severe and widespread threat to the lives of millions of people, especially in developing countries and in the global environment. This review assesses published literature on dryland socio-ecological systems to reveal current research trends and changes in research themes over time and introduces basic theories and advances in dryland socio-ecological system frameworks, resilience measurement, and regime shifts. Developing a more general but adaptable framework and a more practical strategy for long-term coordination and partnership and attaining specific insights into ecological services should receive more attention and be strengthened in future studies on drylands sustainability.
Peng Yu; Zhang Qiuying; Chen Yuanzhan; Xu Ning; Qiao Yunfeng; Tian Chao; Hubert Hirwa; Salif Diop; Aliou Guisse; Li Fadong. Resilience, Adaptability, and Regime Shifts Thinking: A Perspective of Dryland Socio-Ecology System. Journal of Resources and Ecology 2021, 12, 376 -383.
AMA StylePeng Yu, Zhang Qiuying, Chen Yuanzhan, Xu Ning, Qiao Yunfeng, Tian Chao, Hubert Hirwa, Salif Diop, Aliou Guisse, Li Fadong. Resilience, Adaptability, and Regime Shifts Thinking: A Perspective of Dryland Socio-Ecology System. Journal of Resources and Ecology. 2021; 12 (3):376-383.
Chicago/Turabian StylePeng Yu; Zhang Qiuying; Chen Yuanzhan; Xu Ning; Qiao Yunfeng; Tian Chao; Hubert Hirwa; Salif Diop; Aliou Guisse; Li Fadong. 2021. "Resilience, Adaptability, and Regime Shifts Thinking: A Perspective of Dryland Socio-Ecology System." Journal of Resources and Ecology 12, no. 3: 376-383.
Mulched drip irrigation using saline water has the potential to alleviate pressure on crop production from limited freshwater resources in arid and semi-arid regions. To explore the potential of saline water irrigation, it is necessary to investigate how salt stress caused by saline water irrigation affects soil physico-chemical properties and the physiology and growth of crops. The effects of salt stress caused by saline water irrigation are complex and, to date, they are not well understood. We aimed to analyse the distribution and dynamics of these properties to assess their effects on cotton growth, yield, and water productivity during a two-year field experiment using saline water irrigation with various salinity levels (1, 3, 6, 9, and 12 g L−1). Cotton yield, water productivity, and their related components were significantly affected by the different salinity levels. (1) Irrigation water-derived salt accumulated in the soil, especially in the surface soil layer (0–20 cm), but not in the 60–80 cm layer. It was possible to rank cotton main root length based on salinity level as follows: 3 > 1 > 6 > 9 > 12 g L−1. (2) During the growth stage, plants in the 3 g L−1 salinity treatment had transpiration rates 10–30% higher, net photosynthetic rates 20–40% higher, and yields 25–55% higher than those in the other treatments. (3) The 3 g L−1 salinity treatment provided the optimal watering conditions for cotton, and plants in this treatment displayed no salt stress symptoms in terms of their physiology or growth. Therefore, this salinity level is suitable for the mulched drip irrigation of cotton using saline water. Our research provides guidance for further exploitation and utilisation of brackish and saline water resources and sustainable development of irrigated agriculture in semi-arid and arid areas.
Futian Ren; Guang Yang; Wanjing Li; Xinlin He; Yongli Gao; Lijun Tian; Fadong Li; Zelin Wang; Saihua Liu. Yield-compatible salinity level for growing cotton (Gossypium hirsutum L.) under mulched drip irrigation using saline water. Agricultural Water Management 2021, 250, 106859 .
AMA StyleFutian Ren, Guang Yang, Wanjing Li, Xinlin He, Yongli Gao, Lijun Tian, Fadong Li, Zelin Wang, Saihua Liu. Yield-compatible salinity level for growing cotton (Gossypium hirsutum L.) under mulched drip irrigation using saline water. Agricultural Water Management. 2021; 250 ():106859.
Chicago/Turabian StyleFutian Ren; Guang Yang; Wanjing Li; Xinlin He; Yongli Gao; Lijun Tian; Fadong Li; Zelin Wang; Saihua Liu. 2021. "Yield-compatible salinity level for growing cotton (Gossypium hirsutum L.) under mulched drip irrigation using saline water." Agricultural Water Management 250, no. : 106859.
The physical and chemical characteristics of soil and water sources affect desert plants’ growth, which is essential for the ecological protection in arid areas. The typical patch patterns of Haloxylon ammodendron in the oasis-desert ecotone in the southern margin of the Manas River Basin consists of bare patches (BP) and vegetation patches (VP). The water sources of H. ammodendron were studied using stable isotope technology, and the soil physical and chemical properties were monitored and analyzed. The results showed that the soil moisture presented a reversed “S” type curve, and the total salt content of the soil presented an “S” type curve. A “wet island” and “cold island” were formed in the low salt area with H. ammodendron at the center. NaCl was most abundant in the BP soil, and the milligram equivalent of Cl− was 80–90%, while CaSO4 was most abundant in the VP soil, in which the milligram equivalent of SO4 2− was 80–100%. Before the rain, H. ammodendron mainly relied on the soil water from a deeper layer (≥60 cm) to maintain its growth. However, after the rain, H. ammodendron mainly relied on shallow soil water (<60 cm) to maintain its growth.
Li Zhao; Wanjing Li; Guang Yang; Ke Yan; Xinlin He; Fadong Li; Yongli Gao; Lijun Tian. Moisture, Temperature, and Salinity of a Typical Desert Plant (Haloxylon ammodendron) in an Arid Oasis of Northwest China. Sustainability 2021, 13, 1908 .
AMA StyleLi Zhao, Wanjing Li, Guang Yang, Ke Yan, Xinlin He, Fadong Li, Yongli Gao, Lijun Tian. Moisture, Temperature, and Salinity of a Typical Desert Plant (Haloxylon ammodendron) in an Arid Oasis of Northwest China. Sustainability. 2021; 13 (4):1908.
Chicago/Turabian StyleLi Zhao; Wanjing Li; Guang Yang; Ke Yan; Xinlin He; Fadong Li; Yongli Gao; Lijun Tian. 2021. "Moisture, Temperature, and Salinity of a Typical Desert Plant (Haloxylon ammodendron) in an Arid Oasis of Northwest China." Sustainability 13, no. 4: 1908.
Soil respiration (RS) from cropland in response to tillage practices contribute to global climate change. We quantified the effect of no-tillage (NT) and conventional tillage (CT) on RS and precipitation in the North China Plain (NCP). An in-situ automatic sampling and measurement method was applied during the maize (Zea mays L.) growth stages in 2018 and 2019. The continuous daily RS, soil water content and temperature were monitored during all the maize growth stages, whereas maize grain yield, aboveground biomass, and soil microbial biomass were measured after harvest. The mean RS across tillage practices on bright days was higher in 2018 (16.69 g CO2 m−2 d−1) than that in 2019 (12.99 g CO2 m−2 d−1). Compared with CT, NT increased RS on bright days by 31.44% in 2018 and 15.60% in 2019. However, mean RS on rain-affected days across tillage practices was lower in 2018 than that in 2019. NT increased mean RS after precipitation in 2018 (p < 0.05). The contribution of RS after precipitation to cumulative RS (across tillage practices) was higher in 2019 (51.90%) than that in 2018 (41.18%). Mean soil water content and temperature were higher in 2018 than that in 2019 (p < 0.05). NT increased soil water content on bright days in 2019. Furthermore, soil water content was more important in regulating RS in 2018, while soil temperature was more critical after precipitation in 2019. Crop productivity was lower in 2019 than in 2018 (p < 0.05). However, neither crop productivity nor soil microbial biomass varied with tillage practices (p > 0.05). Overall, influence of tillage practices and precipitation on RS were different according to soil water content. Therefore, it is necessary to decrease excessive irrigation to reduce RS in dry years and to conduct continuous observations on RS after precipitation in the NCP.
Kun Du; Fadong Li; Yunfeng Qiao; Peifang Leng; Zhao Li; Jianping Ge; Guang Yang. Influence of no-tillage and precipitation pulse on continuous soil respiration of summer maize affected by soil water in the North China Plain. Science of The Total Environment 2020, 766, 144384 .
AMA StyleKun Du, Fadong Li, Yunfeng Qiao, Peifang Leng, Zhao Li, Jianping Ge, Guang Yang. Influence of no-tillage and precipitation pulse on continuous soil respiration of summer maize affected by soil water in the North China Plain. Science of The Total Environment. 2020; 766 ():144384.
Chicago/Turabian StyleKun Du; Fadong Li; Yunfeng Qiao; Peifang Leng; Zhao Li; Jianping Ge; Guang Yang. 2020. "Influence of no-tillage and precipitation pulse on continuous soil respiration of summer maize affected by soil water in the North China Plain." Science of The Total Environment 766, no. : 144384.
It is important to strengthen the studies on the response of soil respiration components to tillage practices and natural precipitation in cropland. Therefore, soil heterotrophic respiration (RH) and autotrophic (RA) respiration were monitored by a root exclusion method in the North China Plain (NCP). The tillage practices included no-tillage (NT) and conventional tillage (CT), and the study periods were the summer maize growth stages in 2018 and 2019. RH, RA, soil water content and temperature were measured continuously for 113 days by an automatic sampling and analysis system. The soil RH values on bright days and rain-affected days were higher under NT in 2018 (14.22 and 15.06 g CO2 m−2 d−1, respectively) than in 2019 (8.25 and 13.30 g CO2 m−2 d−1, respectively). However, the RA values on bright days and rain-affected days were lower under NT in 2018 (4.74 and 4.97 g CO2 m−2 d−1, respectively) than in 2019 (5.67 and 6.93 g CO2 m−2 d−1, respectively). Moreover, NT decreased RH but increased RA compared to CT in 2019. Compared to bright days, the largest increase in both RH and RA after rain pulses was under CT in 2019 (6.75 and 1.80 g CO2 m−2 d−1, respectively). Soil water content and soil temperature were higher in 2018 than in 2019. Moreover, NT increased soil water content and decreased soil temperature on bright days compared to CT in 2019. Furthermore, soil temperature accounted for more variations in RH on bright days and rain-affected days, but soil water content had a greater influence on RA on bright days. However, after precipitation, higher soil water content decreased RA under NT in 2018, while soil water content was positively related to RA under CT in 2019. This study determined the differential response of RH and RA to tillage practices and natural precipitation pulses, and we confirmed that excessively dry soil increases soil carbon loss after rain events in the NCP.
Kun Du; Fadong Li; Peifang Leng; Zhao Li; Chao Tian; Yunfeng Qiao; Zhaoxin Li. Differential Influence of No-Tillage and Precipitation Pulses on Soil Heterotrophic and Autotrophic Respiration of Summer Maize in the North China Plain. Agronomy 2020, 10, 2004 .
AMA StyleKun Du, Fadong Li, Peifang Leng, Zhao Li, Chao Tian, Yunfeng Qiao, Zhaoxin Li. Differential Influence of No-Tillage and Precipitation Pulses on Soil Heterotrophic and Autotrophic Respiration of Summer Maize in the North China Plain. Agronomy. 2020; 10 (12):2004.
Chicago/Turabian StyleKun Du; Fadong Li; Peifang Leng; Zhao Li; Chao Tian; Yunfeng Qiao; Zhaoxin Li. 2020. "Differential Influence of No-Tillage and Precipitation Pulses on Soil Heterotrophic and Autotrophic Respiration of Summer Maize in the North China Plain." Agronomy 10, no. 12: 2004.
Background Groundwater is typically over-saturated in CO2 with respect to atmospheric equilibrium. Irrigation with groundwater is a common agricultural practice in many countries, but little is known about the fate of dissolved inorganic carbon (DIC) in irrigation groundwater and its contribution to the CO2 emission inventory from land to the atmosphere. We performed a mesocosm experiment to study the fate of DIC entering agricultural drainage channels in the North China Plain. Specifically, we aimed to unravel the effect of flow velocity and nutrient on CO2 emissions. Results All treatments were emitting CO2. Approximately half of the DIC in the water was consumed by TOC production (1–16%), emitted to the atmosphere (14–20%), or precipitated as calcite (CaCO3) (14–20%). We found that DIC depletion was stimulated by nutrient addition, whereas more CO2 evasion occurred in the treatments without nutrients addition. On the other hand, about 50% of CO2 was emitted within the first 50 h under high flow velocity. Thus, in the short term, high nutrient levels may counteract CO2 emissions from drainage channels, whereas the final fate of the produced biomass (burial versus mineralization to CO2 or even CH4) determines the duration of the effect. Conclusion Our study reveals that both hydrology and biological processes affect CO2 emissions from groundwater irrigation channels. The estimated CO2 emission from total groundwater depletion in the North China Plain is up to 0.52 ± 0.07 Mt CO2 year−1. Thus, CO2 emissions from groundwater irrigation should be considered in regional CO2 budgets, especially given that groundwater depletion is expected to acceleration in the future.
Peifang Leng; Fadong Li; Kun Du; Zhao Li; Congke Gu; Matthias Koschorreck. Flow velocity and nutrients affect CO2 emissions from agricultural drainage channels in the North China Plain. Environmental Sciences Europe 2020, 32, 1 -13.
AMA StylePeifang Leng, Fadong Li, Kun Du, Zhao Li, Congke Gu, Matthias Koschorreck. Flow velocity and nutrients affect CO2 emissions from agricultural drainage channels in the North China Plain. Environmental Sciences Europe. 2020; 32 (1):1-13.
Chicago/Turabian StylePeifang Leng; Fadong Li; Kun Du; Zhao Li; Congke Gu; Matthias Koschorreck. 2020. "Flow velocity and nutrients affect CO2 emissions from agricultural drainage channels in the North China Plain." Environmental Sciences Europe 32, no. 1: 1-13.
Background Groundwater is typically over-saturated in CO2 with respect to atmospheric equilibrium. Irrigation with groundwater is a common agricultural practice in many countries, but little is known about the fate of dissolved inorganic carbon (DIC) in irrigation groundwater and its contribution to the CO2 emission inventory from land to the atmosphere. We performed a mesocosm experiment to study the fate of DIC entering agricultural drainage channels in the North China Plain. Specifically, we aimed to unravel the effect of flow velocity and nutrient on CO2 emissions. Results All treatments were emitting CO2. Approximately half of the DIC in the water was consumed by TOC production (1-16%), emitted to the atmosphere (14-20%), or precipitated as calcite (CaCO3) (14-20%). We found that DIC depletion was stimulated by nutrient addition, whereas more CO2 evasion occurred in the treatments without nutrients addition. On the other hand, about 50% of CO2 was emitted within the first 50h under high flow velocity. Thus, in the short term, high nutrient levels may counteract CO2 emissions from drainage channels, whereas the final fate of the produced biomass (burial versus mineralization to CO2 or even CH4) determines the duration of the effect. Conclusion Our study reveals that both hydrology and biological processes affect CO2 emissions from groundwater irrigation channels. The estimated CO2 emission from total groundwater depletion in the North China Plain is up to 0.52 ± 0.07 Mt CO2 y−1. Thus, CO2 emissions from groundwater irrigation should be considered in regional CO2 budgets, especially given that groundwater depletion is expected to acceleration in the future.
Peifang Leng; Fadong Li; Kun Du; Zhao Li; Congke Gu; Matthias Koschorreck. Flow velocity and nutrients affect CO2 emissions from agricultural drainage channels in the North China Plain. 2020, 1 .
AMA StylePeifang Leng, Fadong Li, Kun Du, Zhao Li, Congke Gu, Matthias Koschorreck. Flow velocity and nutrients affect CO2 emissions from agricultural drainage channels in the North China Plain. . 2020; ():1.
Chicago/Turabian StylePeifang Leng; Fadong Li; Kun Du; Zhao Li; Congke Gu; Matthias Koschorreck. 2020. "Flow velocity and nutrients affect CO2 emissions from agricultural drainage channels in the North China Plain." , no. : 1.
The ammonium sulphate ((NH4)2SO4) in-situ leaching process is the most widely used extraction technology for weathered crust elution-deposited rare earth ores (WCED-REOs). Highly concentrated (NH4)2SO4, a representative leaching agent, is often used in the leaching process of WCED-REOs. However, this in-situ leaching process causes nitrogen pollution in the soil, surrounding surface and ground water due to the high concentrations of (NH4)2SO4 solutions used as a long term leaching agent. To date, the mechanism behind the variations in ammonia nitrogen (AN) in deep soil profiles is unclear. We conducted vertical and lateral soil sampling and analyzed the collected samples for soil moisture, pH, ammonia forms, and AN contents in soil profiles deeper than 500 cm in an in-situ leaching mining area of Ganzhou, Jiangxi Province, southern China. The results show that primary chemical pollutants in the soil are derived from residual leaching agents with high acidities and concentrations of AN. Twelve years after the mining process was completed, the mean pH values of the tailings in the mining area were 3.90 and 4.87 in its lower reaches. Due to the presence of chemical residues, the AN concentration was 12–40 times higher than that of the raw ore soil before it was mined. The percentages of different ammonium forms in the rare earth tailing soil were 65%, 30%, and 5% for the water-soluble, exchangeable, and fixed ammonium forms, respectively. The results of this study support effective prevention and remediation treatment of environmental problems caused by AN pollution of the soil in WCED-REOs.
Qiuying Zhang; Futian Ren; Fadong Li; Guoliang Chen; Guang Yang; Jianqi Wang; Kun Du; Shanbao Liu; Zhao Li. Ammonia nitrogen sources and pollution along soil profiles in an in-situ leaching rare earth ore. Environmental Pollution 2020, 267, 115449 .
AMA StyleQiuying Zhang, Futian Ren, Fadong Li, Guoliang Chen, Guang Yang, Jianqi Wang, Kun Du, Shanbao Liu, Zhao Li. Ammonia nitrogen sources and pollution along soil profiles in an in-situ leaching rare earth ore. Environmental Pollution. 2020; 267 ():115449.
Chicago/Turabian StyleQiuying Zhang; Futian Ren; Fadong Li; Guoliang Chen; Guang Yang; Jianqi Wang; Kun Du; Shanbao Liu; Zhao Li. 2020. "Ammonia nitrogen sources and pollution along soil profiles in an in-situ leaching rare earth ore." Environmental Pollution 267, no. : 115449.
Background Groundwater is typically over-saturated with respect to CO2. Irrigation with groundwater is a common agricultural practice in many countries, but little is known about the fate of dissolved inorganic carbon (DIC) in irrigation groundwater and its contribution to the CO2 emission inventory from land to the atmosphere. We performed a mesocosm experiment to study the fate of DIC entering agricultural drainage channels in the North China Plain. Specifically, we aimed to unravel the effect of flow velocity and nutrient on CO2 emissions. Results All treatments were emitting CO2. Approximately half of the DIC in the water was consumed by TOC production (1–16%), emitted to the atmosphere (14–20%), or precipitated as calcite (CaCO3) (14–20%). We found that DIC depletion was stimulated by nutrient addition, whereas more CO2 evasion occurred in the treatments without nutrients addition. On the other hand, about 50% of CO2 was emitted within the first 50 h under high flow velocity. Thus, in the short term, high nutrient levels may counteract CO2 emissions from drainage channels, whereas the final fate of the produced biomass (burial versus mineralization to CO2 or even CH4) determines the duration of the effect. Conclusion Our study reveals that both hydrology and biological processes affect CO2 emissions from groundwater irrigation channels. The estimated CO2 emission from total groundwater depletion in the North China Plain is up to 0.52 ± 0.07 Mt CO2 y− 1. Thus, CO2 emissions from groundwater irrigation should be considered in regional CO2 budgets, especially given that groundwater depletion is expected to acceleration in the future.
Peifang Leng; Fadong Li; Kun Du; Zhao Li; Congke Gu; Matthias Koschorreck. Flow velocity and nutrients affect CO2 emissions from agricultural drainage channels in the North China Plain. 2020, 1 .
AMA StylePeifang Leng, Fadong Li, Kun Du, Zhao Li, Congke Gu, Matthias Koschorreck. Flow velocity and nutrients affect CO2 emissions from agricultural drainage channels in the North China Plain. . 2020; ():1.
Chicago/Turabian StylePeifang Leng; Fadong Li; Kun Du; Zhao Li; Congke Gu; Matthias Koschorreck. 2020. "Flow velocity and nutrients affect CO2 emissions from agricultural drainage channels in the North China Plain." , no. : 1.
To understand the groundwater environmental quality and the impact of trace elements in the construction of urban agglomeration in China, this study collected 58 groundwater samples from the core area of the Chang-Zhu-Tan urban agglomeration (Changsha, Zhuzhou, Xiangtan) and quantitatively analyzed the content of 13 dissolved trace element and their spatial distribution characteristics. The health risk assessment model was further used to evaluate the human health risk caused by trace element pollution in groundwater. It was observed that Ba had the highest average concentration (0.28 mg·L−1), whereas Cd had the lowest (2.1 × 10−5 mg·L−1). Compared with China’s groundwater environmental quality standard, the exceeding rates of Se, Mn, Zn, and Ni concentrations were 37.93%, 17.24%, 1.72% and 1.72%, respectively. Ba, Cd, Co, Cr, Cu, Fe, Mo, and Pb did not exceed the corresponding standards. The 13 trace elements were distributed in a scattered pattern in space and the trace elements in both banks of the Xiang River, Zhuzhou, Weishui River and surrounding areas were relatively high. Health risk assessments showed that the carcinogenic risk values of Cd, Cr, and Pb and the health risk values of 10 non-carcinogenic elements were less than the corresponding maximum acceptable risk level. The health risks associated with non-carcinogenic substances through ingestion were higher than those associated with dermal absorption. Among the non-carcinogenic substances, Ba and Mn posed the greatest health risks. With respect to drinking water exposure, Cr had the highest carcinogenic risk, followed by Pb. Furthermore, Cd had the lowest carcinogenic risk. This study recommended that continuous monitoring of Ba, Mn, and Cr in groundwater should be practiced by assessing the risk of these elements in the Chang-Zhu-Tan urban agglomeration.
Congke Gu; Yan Zhang; Yu Peng; Peifang Leng; Nong Zhu; Yunfeng Qiao; Zhao Li; Fadong Li. Spatial Distribution and Health Risk Assessment of Dissolved Trace Elements in Groundwater in southern China. Scientific Reports 2020, 10, 1 -11.
AMA StyleCongke Gu, Yan Zhang, Yu Peng, Peifang Leng, Nong Zhu, Yunfeng Qiao, Zhao Li, Fadong Li. Spatial Distribution and Health Risk Assessment of Dissolved Trace Elements in Groundwater in southern China. Scientific Reports. 2020; 10 (1):1-11.
Chicago/Turabian StyleCongke Gu; Yan Zhang; Yu Peng; Peifang Leng; Nong Zhu; Yunfeng Qiao; Zhao Li; Fadong Li. 2020. "Spatial Distribution and Health Risk Assessment of Dissolved Trace Elements in Groundwater in southern China." Scientific Reports 10, no. 1: 1-11.
In order to enhance and restore the ecosystems of natural capital in African arid regions, the Global Dryland Ecosystem Programme (G-DEP) consultative meeting was hosted in Dakar, Senegal, from 23 to 25 September 2019. This paper details the first African meeting of the G-DEP. Consultative meeting reviewed preceding dryland ecosystems case studies, identified vulnerable arid and semi-arid regions, and proposed sustainable solutions to problems. It also identified the successes and failures of previous attempts to improve vulnerable ecosystems and ultimately formed an action plan to improve these attempts. Climate, ecosystems, and livelihoods for Sustainable Development Goals (SDGs), Great Green Wall Initiative (GGWI) for Sahara and Sahel, and China-Africa cooperation on science, technology, and innovation are three extra main sections concerned of the meeting. Separately, more specific topics as the complicated relationship between these natural processes and human activity, including pastoralism, soil restoration, and vegetation regenerate techniques, were fully discussed. Consultative meeting also identified the positive effects international collaboration can have on dryland regions, specifically in the capacity of sharing information, technology, and innovation on purpose to develop a joint proposal for long-term research programs in African arid and semi-arid areas. Moreover, meetings that review the progress made on ecosystem management for the sustainable livelihoods in Africa, identification of priority areas, and the development and implementation of ecosystem programs for proper research and collaboration in African arid and semi-arid zones, have been proposed as strategic recommendations to enhance the global partnership for sustainable development. Furthermore, as the outcomes of the workshop, there are three steps proposed to handle African dryland climate changes, several aspects suggested to solve current dilemmas of the GGWI, and a series of actions recommended for G-DEP related activities in Africa.
Yu Peng; Bojie Fu; Linxiu Zhang; Xiubo Yu; Chao Fu; Salif Diop; Hubert Hirwa; Aliou Guisse; Fadong Li. Global Dryland Ecosystem Programme (G-DEP): Africa consultative meeting report. Journal of Arid Land 2020, 12, 538 -544.
AMA StyleYu Peng, Bojie Fu, Linxiu Zhang, Xiubo Yu, Chao Fu, Salif Diop, Hubert Hirwa, Aliou Guisse, Fadong Li. Global Dryland Ecosystem Programme (G-DEP): Africa consultative meeting report. Journal of Arid Land. 2020; 12 (3):538-544.
Chicago/Turabian StyleYu Peng; Bojie Fu; Linxiu Zhang; Xiubo Yu; Chao Fu; Salif Diop; Hubert Hirwa; Aliou Guisse; Fadong Li. 2020. "Global Dryland Ecosystem Programme (G-DEP): Africa consultative meeting report." Journal of Arid Land 12, no. 3: 538-544.
To alleviate surface water shortages during cotton (Gossypium hirsutum L.) cultivation in Xinjiang, the largest cotton producing area in China, we used brackish groundwater resources for mulched drip irrigation in a field. Soil moisture, salinity accumulation, pH, ion concentrations, water-use efficiency, and cotton yield were compared when irrigated using brackish water with five salinities (1g·L−1; 3g·L−1; 6g·L−1; 9g·L−1; and 12g·L−1). Salinity accumulation was significantly stronger in the top soil (0–20 cm depth) than in the deeper soil layer (20–100 cm depth). The soil pH increased and cotton yield decreased accompanied as the brackish water salinity increased. After brackish water mulched drip irrigation was implemented during the cotton growth period, salinity accumulation and cotton yield showed significant differences among the brackish water irrigation treatments. When the salinity was less than 6g·L−1, the accumulated salt in the soil did not seriously affect water absorption by cotton, and the cotton yield was higher than when the salinity was more than 6g·L−1. Therefore, less than 6g·L−1 was a suitable salinity for cotton irrigation with brackish water. As the irrigation salinity increased, the cations gradually changed from Ca2+ to Mg2+ and K+, the anions gradually changed from SO42- and HCO3- to Cl−, and hydro-chemical facies gradually changed from SO42-·HCO3–Ca2+·K+ to SO42-·Cl–Ca2+·K+. This study provides guidance for the scientific management of the soil environment and the used of saline water irrigation for agriculture in the Xinjiang area of Northern China and other regions with similar environments.
Guang Yang; Fadong Li; Lijun Tian; Xinlin He; Yongli Gao; Zelin Wang; Futian Ren. Soil physicochemical properties and cotton (Gossypium hirsutum L.) yield under brackish water mulched drip irrigation. Soil and Tillage Research 2020, 199, 104592 .
AMA StyleGuang Yang, Fadong Li, Lijun Tian, Xinlin He, Yongli Gao, Zelin Wang, Futian Ren. Soil physicochemical properties and cotton (Gossypium hirsutum L.) yield under brackish water mulched drip irrigation. Soil and Tillage Research. 2020; 199 ():104592.
Chicago/Turabian StyleGuang Yang; Fadong Li; Lijun Tian; Xinlin He; Yongli Gao; Zelin Wang; Futian Ren. 2020. "Soil physicochemical properties and cotton (Gossypium hirsutum L.) yield under brackish water mulched drip irrigation." Soil and Tillage Research 199, no. : 104592.
Mulch drip irrigation is widely used in the arid areas of Northwest China. Consequently, the Manas River Basin has developed into the fourth largest irrigated agricultural area in China. In this study, a groundwater model of the regional water cycle was developed to quantitatively assess the groundwater balance in response to different irrigation schemes, including traditional irrigation, conventional water-saving irrigation, and high-efficiency water-saving irrigation schemes. Our results reveal that 1) The water-saving irrigation technology has affected the water cycle process in farmlands. The higher the degree of water conservation, the lower the infiltration into groundwater, the higher the deficit of the groundwater balance, and the more significant the decline of the groundwater level. 2) The groundwater at the Manas River Basin remains in a negative equilibrium state. To achieve an equilibrium state of the groundwater at the Manas River Basin, the catchment management agencies should restrict the scale of oasis development and the utilization of groundwater.
Guang Yang; Lijun Tian; Xiaolong Li; Xinlin He; Yongli Gao; Fadong Li; Lianqing Xue; Pengfei Li. Numerical assessment of the effect of water-saving irrigation on the water cycle at the Manas River Basin oasis, China. Science of The Total Environment 2019, 707, 135587 .
AMA StyleGuang Yang, Lijun Tian, Xiaolong Li, Xinlin He, Yongli Gao, Fadong Li, Lianqing Xue, Pengfei Li. Numerical assessment of the effect of water-saving irrigation on the water cycle at the Manas River Basin oasis, China. Science of The Total Environment. 2019; 707 ():135587.
Chicago/Turabian StyleGuang Yang; Lijun Tian; Xiaolong Li; Xinlin He; Yongli Gao; Fadong Li; Lianqing Xue; Pengfei Li. 2019. "Numerical assessment of the effect of water-saving irrigation on the water cycle at the Manas River Basin oasis, China." Science of The Total Environment 707, no. : 135587.