Terms needed:  Summer 2018, Fall 2018 - June 1-October 30

Faculty mentor name: Ruijun Qin

BES Facility: HAREC

Location (town) of internship:  Hermiston

Hourly Salary: 14       Expected hours/week: 40

Student will have interaction with minors or access to hazardous chemicals. Student will need to complete a criminal background check.

Student will be operating vehicles or farm equipment/machinery. Student will need to submit a driving background.



The Columbia Basin of Eastern Oregon is an important agricultural region supportive of many crops. Potato and onion are the primary high-value crops, while wheat and corn are fundamental rotational-crops. These crops are produced under central pivot irrigation systems, which are intensely managed to optimize crop growth through the application of fertilizer and water. Over multiple decades, the groundwater nitrate level in the region has been increasing and is detected to be above the state drinking water standard (7 mg/L), which triggered the declaration of a Groundwater Management Area (GWMA). Irrigated agriculture is believed to be one of the major contributors, but the related mechanism is not clear. 

After application, nitrogen (N) fertilizer (e.g., ammonium fertilizer or urea) can be transformed to ammonium (NH4+) and nitrate (NO3-) in soil. Both forms are referred to as available N and ready for crop uptake. The NH4+ can be adsorbed or retained by soil, while NO3- is highly mobile within the soil profile and can easily move below the crop root zone contributing to leaching risks. The NO3- leaching risk is highly related to soil types and crops. It may happen much easier in coarse-textured soils due to the low water holding capacity or in the soils with shallow-rooted crops. The root depth is generally around 1.5 ft for potato and onion while 4 ft for wheat and corn, so the high-value crops have higher leaching potential than the rotational crops. Possibly, the rotational crops may scavenge NO3- that has moved below the root zone of the high value crops, essentially creating a cleanup cycle for NO3-, but the related scientific data is limited.

Concurrently, a portion of the N fertilizer can be lost in to air through ammonia (NH3) volatilization and nitrous oxide (N2O) emissions, resulting in reduced fertilizer efficacy, environmental contamination and economic losses. The N2O losses are the main contributor for greenhouse gas emissions; even though the amount of N2O emission is thousandth to that of NH3 emissions.

Although the concept of nitrogen dynamics is well known, the quantified data is very limited for the field production in the Columbia Basin region. Therefore, there is an urgent need for researchers together with growers to evaluate N dynamics under standard grower conditions and develop best management practices for improving nitrogen use efficiency (NUE) and reducing environmental contamination, especially with NO3- leaching for the irrigated fields.

The overall objective of this study is to understand the pathway of N and to quantify crop uptake, nitrate leaching potential, nitrogen distributions in soil profile, and NH3 and N2O emissions associated with fertilization methods. The research results will help growers reduce the environmental issues from N applications and improve NUE in the Columbia Basin region.



This project will provide students experience in gricultural research through laboratory study, field trials, nutrient management, and crop management research. The student will have the chance to gain experience in the soil science and field agronomy programs with the irrigated conditions. The student intern will be expected to observe and collect data on crop growth, take soil and plant samples, measure yield and quality, and submit data/report to the PI.

Applicable majors include soil and crop science, agronomy, horticulture, agricutlrual agineering, environmental sciene, and other agriculture related majors. Applicants should be motivated, hardworking, team-player, and physically able to work in field condictions.

Starting and ending dates will be determined on an individual's needs and project needs. The student intern will be expected to spend 30-40 hours per week for the project. Depending the availability, he/she may also have a chance to work for more research projects, such as biochar application, new crops.