top of page
Bo Yi Successfully Defended His Doctoral Dissertation! Congratulations!

His research focuses on improving our understanding and quantification of soil organic carbon decomposition, as well as reducing uncertainties in carbon modeling.

Mar 25, 2024

IMG_9903 (1).JPG
Congratulations, Bo, on winning the ISU GPSS (Graduate and Professional Student Senate) Research Award—one of the five winners on campus!

He also served on the GPSS Conference Committee and delivered a talk about his research.

Feb 23, 2024

Dr. Lu delivered a webinar at Iowa Learning Farms, titled "Tile-Drainage Decision Tool Helps Manage Agricultural Land and Reduce Nitrogen Pollution."

Watch the Webinar Here

Jan 17, 2024

Congratulations to Ignacio for successfully defending his M.S. thesis and transitioning to a position as an environmental journalist!


Jan 11, 2024

Bo, Shuchao, Ignacio, and Crystal Presented our research work at the 2023 AGU meeting in San Francisco, CA

More details can be found Here

Dec 11, 2023

Fern leaf
Congratulations to Shuchao on receiving the ISU Finch Fund!

This fund will partially support him to quantify the impacts of grassland re-establishment on soil carbon sequestration and GHG reduction.

Nov 29, 2023

N footprint_edited.png
Our Riverine N footprint paper has been published in the Environmental Research Letters!

Water quality is severely degraded in landscapes intensively cultivated for crop production. It has been a long-standing research and practical question: how do we pursue more crop production or economic revenue without sacrificing water quality? Here we propose a riverine N footprint (RNF) concept to quantify how N loads change along with per unit crop production gain. Using data synthesis and a well-calibrated hydro-ecological model, we find that the RNF within the Mississippi-Atchafalaya River Basin peaked at 1.95 g N kg-1 grain during the 1990s, and then shifted from an increasing to a decreasing trend, reaching 0.65 g N kg-1 grain in the 2010s. This implies decoupled responses of crop production and N loads to key agricultural activities approximately after 2000, but this pattern varies considerably among sub-basins.

Paper Link

Oct 30, 2023

Fern leaf
Congratulations to our very own Bo Yi, Ignacio Calderon, and Shuchao Ye on being awarded the EEOB GSO travel fund.

This award will partially support them to attend the 2023 AGU Fall Meeting in San Francisco!

Oct 3, 2023

Fern leaf
Warm welcome to Linchao Li, a postdoctoral researcher who joined us recently!


Aug 24, 2023

Our first catchment-level water quality prediction work has been published in Water Research!

By integrating long-term water quality monitoring data at the delivery scale (the scale before streams) and field-level farming practice information from partnering farmers, this study has improved a spatially distributed process-based land ecosystem model and applied this model in four tile-drained catchments (drainage area ranging from 2-5 km2) in central Iowa. This work conducts model simulation at a 30m by 30m resolution, and examines water discharge and nitrate loading from surface runoff, tile flow, and sub-surface lateral flow. It lays a solid foundation for a decision-support modeling tool on nutrient reduction and water management.

Paper link

Aug 16, 2023

Congratulations to Bo and our fellow co-authors. The paper Bo led has received the "Sino-Eco 2023 Best student Paper Award" at the ESA meeting in Portland, OR

Bo Yi, et al. "Resolving the influence of lignin on soil organic matter decomposition with mechanistic models and continental‐scale data." Global Change Biology (2023).

Aug 10, 2023

Image by Steve Johnson
We currently have an opening for a postdoctoral position, emphasizing the integration of deep learning and process-based hydro-ecological modeling in managed systems.

The selected candidate will collaborate with an interdisciplinary research team to predict rural flood occurrences and nutrient loss from land to aquatic systems. Please contact us at for any questions.

July 20, 2023

We are pleased to announce the publication of a companion paper that highlights how NEON soil lab incubation results significantly contribute to advancing our understanding of lignin decomposition mechanisms and modeling.

We find that, in part of soil samples, lignin decomposition has a "lagged peak", which can be predicted by low soil pH, high extractable Mn, and fungal community compositionOur findings reconcile two competing hypotheses (C substrate limitation and co-metabolism) previously thought to influence lignin decomposition and suggest the need to precisely represent the role of lignin and consider soil metal and fungal characteristics to accurately estimate decomposition in Earth-system modeling.

Paper Link

July 13, 2023

Congratulations to Bo Yi on Successfully Passing the Preliminary Exam and Becoming a PhD Candidate!

Apr 27, 2023

Congratulations to our project team! The lab incubation results of NEON soil samples are truly amazing! 

We find that cumulative lignin decomposition varies 18-fold among soils and is strongly correlated with bulk litter decomposition, but not SOC decomposition. Lignin decomposition increases with some metals and fungal taxa, whereas SOC decomposition decreases with metals and is weakly related with fungi. Decoupling of lignin and SOC decomposition and their contrasting biogeochemical drivers indicate that lignin is not necessarily a bottleneck for SOC decomposition and can explain variable contributions of lignin to SOC among ecosystems.

Paper Link

Apr 19, 2023

Celebrate Peiyu's Farewell as He Embarks on His Postdoctoral Journey at Cornell!

Apr 18, 2023

Fern leaf
Crystal has been invited as a Keynote Speaker for the 11th ISU Environmental Science Graduate Research Symposium.

Apr 17, 2023

Crystal has co-authored a paper that reconstructs a 1-km database detailing the four-century land transformation history of the United States.

The results show widespread expansion of cropland and urban land associated with rapid loss of natural vegetation. The geospatial and long-term historical LULC data from this study provide critical information for assessing the LULC impacts on regional climate, hydrology, and biogeochemical cycles as well as achieving sustainable use of land in the nation. 

Paper Link

March 3, 2023

Find our presentations at the 2022 AGU Fall meeting held in Chicago.

More details


Dec 15, 2022

Fern leaf
We have a postdoc position opening in Coupled hydrological and biogeochemical modeling (supported by two NSF-funded projects).


Nov 1, 2022

Fern leaf
Welcome to our new graduate student, Shuchao Ye! He will work on a USDA-supported project to quantify soil carbon dynamics in the US CRP lands.


Aug 16, 2022

Image by Jacob Rice
Congratulation to Peiyu who successfully defended his Ph.D. dissertation! Hooray!


July 7, 2022

Fern leaf
Recent Awards

Congratulations to our very own Jien Zhang for receiving the 2022 ISU Postdoctoral Research Excellence Award; Peiyu Cao for receiving the 2022 ISU Graduate College Research Excellence Award (REX); and Bo Yi for receiving the honorable mention of EEOB Graduate Student Teaching Award!

July 1, 2022

Our paper published in Nature Food quantified GHG mitigation potentials under the wide adoption of herbicide-resistant crops and emerging weed resistance.

Editor's Summary: Between 1998-2016, the tillage intensity across the U.S. corn-soybean cropping systems has shifted from a decreasing to an increasing trend. The decreasing tillage intensity is correlated to the wide adoption of herbicide-tolerant crops, whereas the tillage reintensification is found to be related to the emergence of herbicide-resistant weed species after 2008. The growing tillage intensity resulted in increased GHG emissions and undermined the GHG mitigation achievements from other activities or other sectors.

Paper Link

April 21, 2022

Check out our new paper on nitrogen loading predictions that is published in Earth's Future.

This study separates the roles of future heavy precipitation, non-heavy precipitation, and no-precipitation days in affecting N leaching loss and predicts the changes in N loading to the Gulf of Mexico. N loading is projected to increase by 30% under two climate scenarios (RCP4.5 and RCP8.5) by the end of the 21st century, half of which is likely driven by heavy precipitation. Our results indicate that more effective nutrient reduction efforts will be needed to reach the reduction goals of N loading and hypoxia extent in the Gulf of Mexico.

Paper Link

April 8, 2022

Figure 4.tiff
Our N2O work is highlighted by Nature Climate Change: Hot Spots for Nitrogen 

"They find that emissions have increased threefold since the beginning of the twentieth century, with agricultural soils driving most of the emissions with a 12-fold increase. Much of this is linked to land-use change and agricultural management practices, with hotspots of emissions in the US Corn and Rice belts, where nitrogen fertilizer is heavily used. "

April 6, 2022

Crystal, Bo, and Jien contributed to the Iowa Carbon Assessment Report. The entire team was selected as a recipient of the 2022 CALS Dean's Citation Award.

Schulte Moore L, Jordahl J, editors. 2022. Carbon Science for Carbon Markets: Emerging Opportunities in Iowa. CROP 3175. Iowa State University Extension and Outreach, Ames, Iowa.

March 1, 2022

Find our historical N2O modeling research on ISU news

As the United States has re-joined the Paris Agreement on climate change with ambitious goals for mitigating greenhouse gas (GHG) emissions, it is of critical importance to understand and quantify how soil N2O emissions, one important biogenic GHG source, varied over space and time, and who dominated contributed to the historical increase in N2O emissions. In this work, the source partitioning and estimations of crop-specific N2O emissions imply a large mitigation potential in croplands and identify dominant contributing crops for future GHG mitigation efforts.

Paper Link

February 15, 2022

Small Green Plants
A big welcome to Ignacio Calderon (MS student) and Yan Zhang (visiting student) who joined us recently!


January 15, 2022

Small Green Plants
Peiyu receives the 2021 Finch fund to support his work on manure management data development.

Finch fund supports undergraduate and graduate students who are doing botanical studies and plant-related research. Peiyu will develop geospatial maps to characterize the rate and timing of manure nitrogen and phosphorous applications in the US croplands.

October 20, 2021

Our work on the half-century history of the US crop nitrogen budget is published in Global Boiogeochemical Cycles! Well done!
we synthesize multiple databases to examine the N budget of eight major crops in the United States at the county scale during 1970–2019. Our analyses show that national crop N use efficiency (NUE) increased from 0.55 kg N kg−1 N in the 1970s to 0.65 kg N kg−1 N in the 2010s. We find that crop N surplus began to decline in the early 2010s and approached the levels in the early 1970s—an encouraging trajectory that reflected reduce agricultural N pollution to the environment.

Paper Link

October 20, 2021

Our new paper published in Agricultural and Forest Meteorology reveals the relationship between crop nitrogen surplus and climate stresses.

We synthesized the county-level crop N budget and climate stress data during 1981-2016. We find that the U.S. corn N surplus dynamics are strongly regulated by climatic stresses. A 51% increase in U.S. corn N surplus was associated with extremely hot conditions. N surplus increases of 47% (dry) and 20% (wet) were related to extreme water stress. The Midwest and the Northern Great Plains are hotspots of climate-driven N surplus.

Paper Link

September 24, 2021

Small Green Plants
Congratulations to Jien who received the 2021 ISU Postdoc Seed Grant. 

This grant will fund him to conduct data mining and data-informed model improvement in water quality predictions. An exciting project!

July 19, 2021

Small Green Plants

May 4, 2021

Congratulations to Peiyu! He received the ISU Brown Graduate Fellowship, one of fourteen recipients on campus!

February 15, 2021

Screen Shot 2021-01-19 at 12.12.44 PM.png
Congratulations to Avani! She successfully defended her thesis via a virtual meeting! Proud of you, Avani!

Her work examined the responses of grassland ecosystems to long-term nitrogen additions through meta-data analysis and data-model intercomparison.

Her thesis can be found here.

January19, 2021

Our research in The Conversation!

November 02, 2020

New study examining heavy rainfall impacts on nitrogen loading is published on Communications Earth & Environment

September 18, 2020

Dr. Lu profiled on the Midwest Big Data Hub

August 24, 2020

NH3 emission.jpg
Our study on fertilizer-induced NH3 emission is now posted as a discussion paper in Atmospheric Chemistry and Physics

February 19, 2020

Dr. Lu received the NSF CAREER award to expand our research in nutrient loading predictions under climate extremes! Way to go!

EEOB highlight

February 14, 2020

Dr. Lu is featured as the researcher spotlight in the NACP (North American Carbon Program) January newsletter 2020

January 28, 2020

Our paper on tillage impact has been accepted by Environmental Research Letters. Wonderful Christmas gift!

Using time-series tillage maps developed from a private survey and a process-based land ecosystem model, here we examined how tillage intensity has changed across the nation and affected soil organic carbon (SOC) storage from 1998 to 2016.

Paper Link

December 23, 2019

Crop-specific NUE_Lu.jpg
Dr. Lu has an invited talk on the 100th AGU meeting, in which she presented the half-century database of county-level crop-specific nitrogen budget and nitrogen use efficiency (NUE) across the US.

December 13, 2019

Small Green Plants
Congratulations to Luke Sloterdyk! He received the Finch fund from EEOB to support his research project in Lu's lab

December 12, 2019

The kickoff meeting was held at ISU for a new NSF funded project: CNH2-S: Sustainable field-to-market supplychains enabled by blockchain networks.

August 30, 2019


August 28, 2019

Small Green Plants
A big welcome to graduate students Bo Yi, Geunhu Kim, rotation graduate student Henri Chung, and undergraduate researcher Luke Sloterdyk who joined us this semester!

August 19, 2019

Small Green Plants
New grant from NSF to support collaborative research on sustainable field-to-market supply chains enabled by blockchain networks

July 25, 2019


Our recent work demonstrating spatiotemporal patterns of crop nitrogen use efficiency across the United States

Paper Link

July 25, 2019

New study reveals the underestimated carbon source from land use and land cover change in the continental US

Paper Link

July 16, 2019


New grant from NSF to support the U.S.-China joint research on INFEWS (Innovations at the Nexus of Food-Energy-Water Systems)

July 01, 2019

Small Green Plants

Congratulations to Dr. Zhen Yu! He got a faculty position at the School of Applied Meteorology, Nanjing University of Information Science and Technology, China, and will start building up his own research team soon.

May 27, 2019

Small Green Plants
Congratulations to Dr. Zhen Yu who won the 2019 ISU Postdoctoral Scholar Research Excellence Award!

May 14, 2019

Figure 5_edited.jpg
Our paper investigating terrestrial carbon fluxes and long-lasting drought events has been accepted by Geophyical Research Letters

Paper Link

May 08, 2019

Small Green Plants
Congratulations to Zhen who won the 2019 Outstanding Doctoral Research Award from International Union of Forest Research Organizations (IUFRO)!

January 30, 2019

Zhen, Jien, Peiyu, and Crystal presented our work at the 99th AGU fall meeting held in Washington DC.

December 10, 2018

Small Green Plants
We recieved the ISU publication Subvention Grant!

November 28, 2018

With a number of scientists from multiple countries, Crystal co-authored a paper published in Global Change Biology, which quantified global soil N2O emissions

November 10, 2018

updated Fig1.png
Our paper published in Environmental Research Letters reveals increasing carbon footprint in the Western Corn Belt

November 10, 2018

Small Green Plants
Congratulations to Dr. Zhen Yu who won the 1st prize of the 2018 MCED (Modelling Complex Ecological Dynamics) Modeling Award!

August 30, 2018

Small Green Plants
Congrats to Dr. Zhen Yu for receiving an Iowa State University Postdoctoral Association Seed Grant Award!

August 06, 2018

Bear_Creek_update (1).tif
New grant from Iowa Nutrient Research Center to support our modeling study for tracking nitrate movement from agricultural land to streams

June 25, 2018

Fig 4_edited.jpg
Dr. Lu co-authored a paper published in Current Opinion in Environmental Sustainability

June 11, 2018

Our work on historical patterns of agricultural nitrogen fertilizer use in the U.S. has been published in Earth System Science Data

Paper Link

June 04, 2018

Small Green Plants
New grant from NSF Macrosystems Biology and Early NEON Science program will support collaborative research on ligin decomposition analysis and modeling

May 20, 2018

The work Dr. Lu co-authored was highlighted in EOS Research Spotlight

January 30, 2018

Small Green Plants
A big welcome to postdoc Jien Zhang who has joined our lab!

January 25, 2018

Our work on terrestrial carbon dynamics in the midwest US is in press in Global Change Biology

January 22, 2018

Dr. Lu co-authored a paper published in Bulletin of the American Meterological Society (BAMS), which addressed the status of global N2O model intercomparison project (NMIP)

January 09, 2018

Our work on US land use history is published in Global Ecology and Biogeography

December 21, 2017

Our work on spatiotemporal patterns of historical nitrogen fertilizer uses in the US is under discussion in Earth System Science Data

December 18, 2017

Dr. Lu co-authored a paper published in Journal of Advances in Modeling Earth Systems, in which herbivore population dynamics were coupled into a global land model, DLEM.

December 17, 2017

Our work on "Earlier leaf-flushing suppressed ecosystem productivity by draining soil water in the Mongolian Plateau" is published in Agricultural and Forest Meteorology

December 12, 2017

Small Green Plants
Dr. Lu served as faculty panelist for ISU Climate Reality Club to share her understanding of climate change impact on land ecosystems

October 26, 2017

Small Green Plants
Zhen Yu won the Outstanding Young Scholars Award from the 12th International Congress of Ecology (INTECOL 2017 Beijing) held during August 20-25, 2017 in Beijing, China

August 20, 2017

Small Green Plants
Undegrad, Alina Lu, joined our lab!

August 16, 2017

Small Green Plants
Avani Khadilkar, PhD student in Bioinformatics and Compuptational Biology, joined our lab!

August 16, 2017

Small Green Plants
Dr. Lu and Zhen Yu attended the 2017 North American Carbon Program (NACP) AmeriFlux PI Meeting in Bethesda, MD, and presented our work conducted in the continental U.S.

March 27, 2017

Our geospatial database on global fertilizer use rate has been published in Earth System Science Data

March 02, 2017

Small Green Plants
DLEM code has been ported from Windows to Linux System

September 29, 2016

Small Green Plants
First grduate student, Peiyu Cao, joined the lab through Environmental Science Graduate Program!

August 16, 2016

Dr. Lu joined Yiqi Luo and others in CCIWG (Carbon Cycle Interagency Working Group)/NACP (North American Carbon Program) workshop to discuss Development of Predictive Carbon Cycle Science, College Park, Maryland

March 09, 2016

Small Green Plants
Dr. Lu joined Amy Hessl, Hanqin Tian, Jiquan Chen, Neil Pederson and others in the Climate and Ecology of the Mongol Empire writing workshop at Harvard Forest

February 05, 2016

Small Green Plants
First postdoc, Zhen Yu, arrived at Ames!

May 25, 2016

Dr. Lu's study in biogenic GHG balance published in Nature

March 09, 2016

Dr. Lu served as a panelist of Workshop on The Food-Energy-Water Nexus in Asia and its Global Implication

January 19, 2016

Small Green Plants
Dr. Lu convened the session " Closing the global nitrous oxide budget: magnitude, spatiotemporal patterns and responses", and give presentation on the 2015 AGU Fall Meeting in San Francisco, CA

December 15, 2015

Figure_SOC framework.jpg
Our SOC study has been highlighted by DOE EMSL (Environmental Molecular Sciences Laboratory) News " How to improve soil carbon models"

September 01, 2015

Small Green Plants
As China Ecological Forum's 119th lecturer since 2005, Dr. Lu offered a presentation entitled "Multi-scale Responses of Terrestrial Ecosystem to Reactive Nitrogen Enrichment in the Context of Global Changes: Toward Translational Research for a Sustainable Future" .

August 01, 2015

Small Green Plants
Dr. Lu joined the department of Ecology, Evolution, & Organismal Biology at ISU

August 01, 2015

bottom of page