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Lab Support

Thank you to the following for making this research possible:

Visting Scholar:

Dr. Ku Wang

Dr. Ku WangCurrently, Dr. Wang is working on soil health mapping and precision optimization for nitrogen fertilization using on-the-go sensors and aerial/satellite imageries. His research is focused on mixed geographically weighted regression (MGWR), the purpose of the research is aimed to construct accurate MGWR models for estimating soil properties. Dr. Wang has been a visiting scholar at the University of Connecticut from September 2010 to March 2011. He earned his Ph.D. in Soil Science and his MA in Soil and Water Conservation from the Chinese Academy of Soils and his BA in Soil and Plant Nutrition from Nanjing Agricultural University.

Contact Dr. Wang via email at

Dr. Wang’s CV (pdf).

Graduate Students:

Katherine Naasko

Katherine NaaskoKatherine was born and raised in the Great Lakes state and has always been aware of the importance of environmental conservation and sustainability. Her interests led her to receive a Bachelor’s degree in chemistry, with two minors focusing on environmental sustainability, technology & policy at Michigan State University. While finishing her last year of school, Katherine worked in the MSU Soil and Plant Nutrient laboratory where she was exposed to the fascinating world of soil and crop science. Here at WSU, she begins her Ph.D. in Soil Science under Dr. Haiying Tao in the spring of 2018, where she will be exposed to invaluable resources and connections as a teaching and research assistant. One project Katherine is working on focuses on using a byproduct from paper mills called black liquor as a soil amendment, specifically its unique characteristics that when mixed with lime applications, it aids in movement a nd utility of limes in soils. Another project she is working on is in partnership with the NCRS, in which we are focusing on implementing widespread soil health by integrating different soil sampling and testing methods to create applicable, helpful guidelines to farmers, researchers and analysists. Katherine is looking forward to making advancements in soil health and fertility in the PNW.

Contact Katherine via email at

Melissa Porter

Marissa is a Soil Science Master’s student at Washington State University. She completed her undergraduate studies at Marist College, receiving a Bachelor of Science in Environmental Science. Growing up in New England, she developed an environmental consciousness at a young age and since then has been passionate about and committed to mitigating our anthropogenic impacts on the world. Her diverse research experience as an undergrad gave her a broad perspective of the environmental challenges the world faces today. This knowledge put agriculture as the central connected system between humans and the natural world and led to her choosing to pursue graduate studies in soil science. Her research thus far at Washington state is studying the nitrogen use efficiency of canola, a relatively new crop in the region. Her project will help improve the fertility knowledge of canola, helping to integrate it as a rotational crop in the winter-wheat summer fallow cropping system.

Contact Marissa by email at

Rachel Smith

Rachel Breslauer in a canola field.Rachel is a second-year master’s student in soils advised by Dr. Tao. She is studying how varied landscape positions and soil properties at depth affect nitrogen uptake and use in winter wheat. She has enjoyed collaborating with farmers, researchers, and extension personnel during her time at WSU.

Rachel likes to spend her free time backpacking, painting, cooking, and making soap.

Contact Rachel by email at

Research Associate:

Wanling Li

Wanling LIWanling is an Associate Researcher in the Soil Fertility Laboratory in the Department of Crop and Soil Science at Washington State University in Pullman.

Wanling is currently leading a project investigating how soil acidification affects crop roots development. Wanling manages the soil fertility laboratory. She helps graduate students on lab procedure preparations and participates on-farm research work during busy sampling seasons.

Wanling enjoys the outdoors, photograph, playing the violin, cooking, and exercising in her free time. Seeing Northern lights is one of her dreams.

Contact Wanling via email at

Field Technician:

Zach Smith

Zach Smith in fieldZach began working in soil science his sophomore year at WSU at the Conservation Farm and Agroecology lab under Dr. Dave Huggins. He worked as a lab and field hand for 2 and a half years before graduating with a degree in Integrated Plant Science from WSU Pullman and is transitioning over to Dr. Tao’s lab as a field technician.

Contact Zach via email at

Haiying Tao Biography

Haiying Tao – PI – is an assistant professor of Soil Fertility and Residue Management in the Department of Crop and Soil Sciences at WSU. Prior to joining WSU, Haiying was an associate research scientist at the University of Connecticut, working on 4R stewardship for nitrogen and best nutrient management practices for corn/soybean in different soil and climate conditions. She received her Ph.D. in Soil Science from the University of Connecticut, MS in Agronomy from China Agricultural University, and BS in Agronomy and BS minor in Agricultural Economics from China Agricultural University. Her current research focuses on soil nutrient and residue management practices that are friendly for yield, economics, and the environment. Her extension education activities will be needs-driven by the agricultural production community in the state of Washington and neighboring states. Specific areas of research and extension include nitrogen optimization, residue management, soil acidification, soil health, precision agriculture, land application of manure, nutrient management planning.

Haiying’s Curriculum Vitae (pdf)