Educational Background:

I received my BS degree in Soils from Washington State University in 1982, MS degree in Soils from Montana State University in 1986, and PhD in Agronomy from Cornell University in 1993.

Research Program: Agronomy

Current Research Projects:

Further improvements in crop productivity and revenue may come from precision agriculture strategies that rely on modern information technologies to bring data from multiple sources to influence crop management decisions. I am investigating the use of high resolution information from in-line spectroscopic sensors in the following three projects:

• Precision Nitrogen Management

Future improvements in nitrogen (N) fertility management will require an understanding of how we can best manage fertilizer resources under varying soil conditions. I am investigating how information from on-combine yield monitors and optical sensors can be applied into N management thereby improving grain quality and yield. Because of the correlation between grain protein and plant N nutrition, optical sensing provides an opportunity for growers to use grain protein maps to assess spatial variability in soil N fertility levels. This approach could lead to improved soil sampling protocols that direct sampling to areas of a field that are deficient in N. Plus, the resulting grain protein maps can also be a useful post-harvest indicator of whether the N supply was sufficient for optimum wheat yields.

• Grain Segregation by Protein Concentration

Variability in grain yield arises from differences in crop management, soil fertility, weather events, timing of harvest, and other factors. These same factors produce extreme variation in grain quality as well. Despite this variability, traditional harvesting systems tend to keep the grain from a field together in the same bin. I am investigating whether grain segregation, involving the physical separation of grain during harvest into lots of low protein and high protein, can overcome limitations of conventional harvesting systems that ignore spatial variability. I believe that growers can profit when elevators desire superior quality, soft white winter wheat to take advantage of current (or future) opportunities for blending to capture premiums or meet contract specifications.

• Assessing straw yield in dryland wheat fields

Historically, wheat straw has been thought of as waste from grain harvesting operations, but its importance as a material for livestock feed or biofuel feedstock is increasing. I am using on-combine sensors to measure levels of grain yield, protein, and crop biomass across farm fields and applying this information into mapping the quantity and quality of wheat straw. The resulting straw maps will be important for determining where surplus residue, beyond soil conservation requirements, can be removed for economic reasons.

Additional Research Interests:

Additional topics that I have recently investigated, or am investigating, include the following:

• Soil carbon and nitrogen dynamics following a conversion from alternate winter wheat-summer fallow to perennial bioenergy crops.
• Effect of planting method on establishment of spring canola.
• Performance of on-combine optical NIR sensing of grain protein concentration
• Remote sensing of foliar N content in dryland wheat fields for late season N management.
• Effect of soil variability on remote sensing of wheat N content in dryland wheat fields