Xin Zhang

Xin Zhang
University of Maryland Center for Environmental Science | UMCES · Appalachian Laboratory

PhD

About

59
Publications
36,639
Reads
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2,889
Citations
Additional affiliations
November 2012 - November 2014
Princeton University
Position
  • PostDoc Position
November 2012 - November 2014
Woodrow Wilson International Center for Scholars
Position
  • PostDoc Position
August 2007 - November 2012
Yale University
Position
  • PhD Student

Publications

Publications (59)
Article
A global analysis finds that nitrogen fertilizers could be used more efficiently if their international distribution across croplands was altered [mdash] a measure that would also decrease nitrogen pollution.
Article
Full-text available
Improvements in nitrogen use efficiency in crop production are critical for addressing the triple challenges of food security, environmental degradation and climate change. Such improvements are conditional not only on technological innovation, but also on socio-economic factors that are at present poorly understood. Here we examine historical patt...
Article
Full-text available
Technologies and management practices (TMPs) that reduce the application of nitrogen (N) fertilizer while maintaining crop yields can improve N use efficiency (NUE) and are important tools for meeting the dual challenges of increasing food production and reducing N pollution. However, because farmers operate to maximize their profits, incentives to...
Article
Full-text available
Quantification of regional greenhouse gas (GHG) fluxes is essential for establishing mitigation strategies and evaluating their effectiveness. Here, we used multiple top-down approaches and multiple trace gas observations at a tall tower to estimate GHG regional fluxes and evaluate the GHG fluxes derived from bottom-up approaches. We first applied...
Article
Full-text available
Abandoned oil and gas wells provide a potential pathway for subsurface migration and emissions of methane and other fluids to the atmosphere. Little is known about methane fluxes from the millions of abandoned wells that exist in the United States. Here, we report direct measurements of methane fluxes from abandoned oil and gas wells in Pennsylvani...
Article
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The expansion of plantations, such as oil palm, in Indonesia has caused large-scale deforestation. Loss of tropical forest, in particular peatland forest, is a major ecological and environmental threat as well as a source of atmospheric carbon emissions. Understanding the spatio-temporal dynamics of plantation expansion may illuminate pathways to r...
Article
Full-text available
Global use of reactive nitrogen (N) has increased over the past century to meet growing food and biofuel demand, while contributing to substantial environmental impacts. Addressing continued N management challenges requires anticipating pathways of future N use. Several studies in the scientific literature have projected future N inputs for crop pr...
Article
Improving manure management can reduce nitrous oxide (N2O) emissions, but its impacts on indirect N2O emissions and other greenhouse gases need to be assessed. Structural changes that address livestock demands and spatial planning are needed.
Article
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Protecting tropical peat swamp forests in Southeast Asia is critical for addressing global sustainability challenges such as climate change and biodiversity loss. However, more than half of these forests have been lost since 1990 due to the rapid expansion of drainage-based agriculture and forestry. Within the oil palm sector, regional smallholder...
Article
Full-text available
We are delighted to publish the names of the 613 peer reviewers who submitted 904 reviews in 2021. We express our deep appreciation for your thoughtful comments and suggestions on manuscripts submitted to Earth's Future.
Article
Since the 1950's, global fertilizer usage has increased by more than 800% resulting in detrimental impacts to the environment. The projected increase in crop production due to increasing demands for food, feed, biofuel, and other uses, may further increase fertilizer usage. Studies have examined achieving agricultural intensification in environment...
Article
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Dietary shifts from staples toward meats, fruits, and vegetables increase environmental impacts. Excessive red meat intake and micro-nutrient deficiencies also raise health concerns. Previous research examined environmental and health consequences of alternative diets but overlooked impacts on air pollution and land use change. Here we examine impl...
Article
Estimating realistic potential yields by crop type and region is challenging; such yields depend on both biophysical characteristics (e.g., soil characteristics, climate, etc.), and the crop management practices available in any site or region (e.g., mechanization, irrigation, crop cultivars). A broad body of literature has assessed potential yield...
Chapter
Static program analysis uses sensitivity to balance between precision and scalability. However, finer sensitivity does not necessarily lead to more precise results but may reduce scalability. Recently, a number of approaches have been proposed to finely tune the sensitivity of different program parts. However, these approaches are usually designed...
Article
Full-text available
Agriculture is fundamental to all three pillars of sustainability, environment, society, and economy. However, the definition of sustainable agriculture and the capacities to measure it remain elusive. Independent and transparent measurements of national sustainability are needed to gauge progress, encourage accountability, and inform policy. Here,...
Article
Fertilizer overuse by smallholder farmers is widespread in China, leading to significant financial losses and threatening the environment. Understanding what mechanism behind this is critical for agricultural and environmental sustainability. By using a fixed effect panel model of over 20,000 rural households in China from 1995 to 2016, we found th...
Article
Nitrogen (N) is an essential nutrient to support life, but if poorly managed, can adversely affect the environment, ecosystems and human health. The global challenge of achieving food security with minimal ecosystem degradation and human health impacts hinges on sustainable N management, which goes beyond farm level and requires concerted efforts f...
Article
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The consideration of tariffs on China’s imports of US agricultural products has focused on economic impacts, while the environmental consequences have received less attention. Here we use a global computable general equilibrium model to evaluate long-term crop portfolio changes induced by China’s retaliatory agricultural tariffs and thereby assess...
Article
Full-text available
Input–output estimates of nitrogen on cropland are essential for improving nitrogen management and better understanding the global nitrogen cycle. Here, we compare 13 nitrogen budget datasets covering 115 countries and regions over 1961–2015. Although most datasets showed similar spatiotemporal patterns, some annual estimates varied widely among th...
Article
Full-text available
Nitrogen (N) fertilization has boosted grain production during the past century, while excess N fertilization with declining N use efficiency (NUE) has led to severe pollution in many regions. To achieve the goal of sustainable food production, Technologies and Management Practices (TMPs, e.g., optimum N application rate and methods, N‐transformati...
Article
Full-text available
Nitrogen use efficiency (NUE) is a key indicator with which to study nitrogen cycles and inform nitrogen management. However, different quantification approaches may result in substantially divergent NUE values even for the same production system or for the same experimental plot. Based on our investigation of the differences between and connection...
Article
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This paper redefined the agricultural production system and its subsystems with respect to phosphorus (P) flow to improve the assessment of the phosphorus use efficiency (PUE), which is a key indicator for P security and sustainability of water resources. It also assessed the key P inflows, outflows, and PUE in the crop-pasture subsystem, livestock...
Article
Full-text available
Human land use activities have resulted in large changes to the biogeochemical and biophysical properties of the Earth’s surface, with consequences for climate and other ecosystem services. In the future, land use activities are likely to expand and/or intensify further to meet growing demands for food, fiber, and energy. As part of the World Clima...
Article
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Based on data from previous ¹⁵N‐tracer trials, Yan et al. (Global Change Biology, 26, 191–199; 2020) accounted the sources of cereal crop nitrogen (N) from fertilizer inputs (from both current and previous seasons) and possible uptake of nonfertilizer N inputs, leaving a significant part of N source undefined. We argue that the undefined N source d...
Preprint
Full-text available
Nitrogen use efficiency (NUE) has been widely used in cropping systems to study nitrogen (N) cycles and inform N management on various spatial scales, from a single plant to the globe. Although the number of NUE studies is growing, interpretation of results is unfortunately hindered by widely differing definitions and quantification methods among s...
Article
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The increased use of legumes is viewed as a promising option to mitigate climate change, as they are a source of proteins and provide nitrogen to the soil. In this paper, we evaluate a strategy for the increased use of legumes in Europe until 2050 by integrating a large array of food and natural system processes into a consistent modeling framework...
Preprint
Full-text available
Abstract. Human land-use activities have resulted in large changes to the biogeochemical and biophysical properties of the Earth surface, with consequences for climate and other ecosystem services. In the future, land-use activities are likely to expand and/or intensify further to meet growing demands for food, fiber, and energy. As part of the Wor...
Article
Full-text available
Nutrients, such as nitrogen and phosphorus, provide vital support for human life, butoverloading nutrients to the Earth system leads to environmental concerns, such as water and airpollution on local scales and climate change on the global scale. With an urgent need to feed the world'sgrowing population and the growing concern over nutrient polluti...
Article
Humanity's transformation of the nitrogen cycle has major consequences for ecosystems, climate and human health, making it one of the key environmental issues of our time. Understanding how trends could evolve over the course of the 21st century is crucial for scientists and decision-makers from local to global scales. Scenario analysis is the prim...
Article
Full-text available
China increasingly relies on agricultural imports, driven by its rising population and income, as well as dietary shifts. International trade offers an opportunity to relieve pressures on resource depletion and pollution, such as nitrogen (N) pollution, while it poses multiple socioeconomic challenges, such as food availability. To quantify such tr...
Article
The “4R” fertilizer management principles of using the right rate, right source, right timing and right place is emergently required for enhancing crop production and improving crop Nitrogen Use Efficiency (NUE) in intensive small farming system. However, the methodology is still vague to design and implement technologies and management practices (...
Article
Full-text available
Nitrogen is a critical component of the economy, food security, and planetary health. Many of the world's sustainability targets hinge on global nitrogen solutions, which, in turn, contribute lasting benefits for (i) world hunger; (ii) soil, air, and water quality; (iii) climate change mitigation; and (iv) biodiversity conservation. Balancing the p...
Article
Full-text available
Accurate projections of the terrestrial carbon (C) sink are critical to understanding the future global C cycle and setting CO2 emission reduction goals. Current earth system models (ESMs) and dynamic global vegetation models (DGVMs) with coupled carbon‐nitrogen cycles project that future terrestrial C sequestration will be limited by nitrogen (N)...
Article
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China needs to manage its coal-dominated power system to curb carbon emissions, as well as to address local environmental priorities such as air pollution and water stress. Here we examine three province-level scenarios for 2030 that represent various electricity demand and low-carbon infrastructure development pathways. For each scenario, we optim...
Article
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Nitrous oxide (N2O) is an important greenhouse gas and ozone depleting substance. Previous projections of agricultural N2O (the dominant anthropogenic source) show emissions changing in tandem, or at a faster rate than changes in nitrogen (N) consumption. However, recent studies suggest that the carbon dioxide (CO2) fertilization effect may increas...
Technical Report
Full-text available
Installment 11 of Creating a Sustainable Food Future shows that for people who consume high amounts of meat and dairy, shifting to diets with a greater share of plant-based foods could significantly reduce agriculture’s pressure on the environment. It introduces a protein scorecard ranking foods from lowest (plant-based foods) to highest impact (be...
Technical Report
Full-text available
Installment 11 of Creating a Sustainable Food Future shows that for people who consume high amounts of meat and dairy, shifting to diets with a greater share of plant-based foods could significantly reduce agriculture’s pressure on the environment. It introduces a protein scorecard ranking foods from lowest (plant-based foods) to highest impact (be...
Article
Full-text available
Nitrogen (N) pollution is emerging as one of the most important environmental issues of the 21st Century, contributing to air and water pollution, climate change, and stratospheric ozone depletion. With agriculture being the dominant source, we tested whether it is possible to reduce agricultural N pollution in a way that benefits the environment,...
Article
Full-text available
Quantification of regional greenhouse gas (GHG) fluxes is essential for establishing mitigation strategies and evaluating their effectiveness. Here, we used multiple top-down approaches and multiple trace gas observations at a tall tower to estimate regional-scale GHG fluxes and evaluate the GHG fluxes derived from bottom-up approaches. We first ap...
Conference Paper
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Article
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This study seeks to quantify the roles of soybean and corn plants and the cropland ecosystem in the regional N2O budget of the Upper Midwest, USA. The N2O flux was measured at three scales (plant, the soil-plant ecosystem, and region) using newly designed steady-state flow-through plant chambers, a flux-gradient micrometeorological tower, and conti...
Article
[1] Nitrous oxide (N2O) is a greenhouse gas with a large global warming potential and is a major cause of stratospheric ozone depletion. Croplands are the dominant source of N2O, but mitigation strategies have been limited by the large uncertainties in both direct and indirect emission factors (EFs) implemented in “bottom-up” emission inventories....
Article
Full-text available
The primary objective of this study was to clarify the influence of crop plants on atmospheric methane (CH4) in an agriculture-dominated landscape in the Upper Midwest of the United States. Measurements were carried out at two contrasting scales. At the plant scale, CH4 fluxes from soybean and corn plants were measured with a laser-based plant cham...
Chapter
Full-text available
Accurate measurement of carbon stocks and flux in forests is one of the most important scientific bases for successful climate and carbon policy implementation. Currently, there are several methods for estimating forest carbon stocks and flux. We review the four categories of methods for measuring forest biomass and estimating carbon which are curr...
Article
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1] The oxygen isotope of water (18 O‐H 2 O) and carbon dioxide (18 O‐CO 2) is an important signal of global change and can provide constraints on the coupled carbon‐water cycle. Here, simultaneous observations of 18 O‐H 2 O (liquid and vapor phases) and 18 O‐CO 2 were used to investigate the relation between canopy leaf water 18 O enrichment, 18 O‐...
Article
Full-text available
As the third primary greenhouse gas and the largest ozone-depleting substance, nitrous oxide (N2O) has been researched extensively to determine its global budget. However, large uncertainties still exist in estimating the strength of the sources and sinks related to agricultural activities. The estimates of N2O emission from agricultural activities...
Article
Full-text available
The oxygen isotope composition of evapotranspiration (δ F ) represents an important tracer in the study of biosphere-atmosphere interactions, hydrology, paleoclimate, and carbon cycling. Here, we demonstrate direct measurement of δ F based on the eddy-covariance and tunable diode laser spectroscopy (EC-TDL) techniques. Results are presented from la...
Article
In order to characterize the budgets of three major greenhouse gases (CO2, CH4 and N2O) from cropland, we conducted an experiment near Rosemount, Minnesota, in a landscape dominated by soybean and corn faming. The experiment was carried out at the plant, the ecosystem, and the regional scales. A steady-state flow-through chamber was used to measure...

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