Nutrient Management, Cycling, & Distribution
My research program responds to needs and interests of Kansas agricultural and environmental communities through the study of chemical, biological, and management factors affecting nutrient availability and loss in agroecosystems. Research focuses on nutrient management, cycling, and distribution within soil profiles and across landscapes. My interests include the investigation of nutrient availability in agricultural and industrial by-products and their impacts on agricultural sustainability and nutrient loss.
I enjoy research studies at multiple scales, such as lab, small plot, field, and watershed-scale projects. I am also interested in incorporating new technologies, such as computer simulation models, GIS and GPS, or precision agriculture into research projects.
Cover Crop Effects on Phosphorus Loss
We are investigating the effects of cover crops and P fertilizer management on P loss in surface runoff at the Kansas Agricultural Watershed Field Laboratory. We have found that cover crops decrease sediment loss by 70% in no-till corn soybean production. Although sediment loss is decreased, total P loss is unaffected because of increased dissolved P loss. The dissolved and total P loss can be decreased by subsurface placement of P fertilizer. More results are at the project website (www.ksu.edu/kaw).
Sulfur, Nitrogen and Genetic Effects on Winter Wheat Yield and Asparagine Content
Initial results show that sulfur fertilizer application can increase yield and decrease asparagine concentrations in winter wheat. We found that S also improves N response and decreases the negative effects of high N fertilization on asparagine.
Manganese Response in Glyphosate Resistant Soybean
For this project we investigated the hypothesis that glyphosate-resistant soybean is more responsive to Mn applications than near-isoline conventional soybean. Data are discussed in a thesis by Jami Loecker and final results are published in the Agronomy Journal, 102:606-611.
Phosphorus Loss From Stream Sediments and Stream Banks
Although best management practices are generally focused on controlling phosphorus (P) losses at field scales, many physical and chemical processes influence the eventual P loading to down-stream water bodies. For this study, we are investigating the P sorption and desorption of stream sediments in comparison with field soils as a means of identifying potential P sources to stream water during storm events and base flow. Our investigation includes the effects of soil, sediment, management, and stream geomorphology on P loading to surface waters in two Kansas watersheds.
Cheney Lake Conservation Effects Assessment Project (CEAP)
Water quality effects of strategically implementing specific conservation practices in targeted locations will be studied from October 2006 through September 2009 in the Cheney Lake Watershed located in South-central Kansas. Over the past 10 years, conservation practices have been implemented in the watershed on a voluntary basis, which may or may not place practices in areas of greatest need. This interdisciplinary project will use a combination of data sources from field monitoring, computer modeling, producer interviews, and historical data coupled with statistical, spatial, economic, and social analysis to answer the following 3 basic questions:
- How does the timing, location, and suite of conservation practices affect water quality at the watershed scale?
- How do social and economic factors affect conservation practice implementation?
- What is the optimal placement and suite of conservation practices for the given watershed?
- Modeling crop rotation and tillage effects on field-scale water quality with the SWAT to model.
- Modeling temporal and spatial effects of no-till conversion on water quality improvement at the watershed scale with SWAT.
- Use of GIS to estimate field-scale erosion and prioritize BMP placement.
- Trend analysis of historical water quality data.
Estimating Nitrogen Availability From Manure
Estimates of N availability from manure applications are complicated by manure variability, ammonia volitilization during application, and varibility in N mineralization among other factors. The objective of this project is to evaluate the use of crop canopy sensors, such as the GreenSeeker, to adjust in-season N applications in fields that receive pre-plant N in the form of animal manure.
Heartland Phosphorus Index Conservation Innovation Grant
Increasing Nitrogen Use Efficiency in Winter Wheat
Land Application of Biochar
Biochar Effects On Nutrient Availability in Soils: Biochar is a potentially valuable co-product of the thermo-chemical conversion of biomass to biofuel. The biochar can potentially improve soil structure, nutrient availability, and C sequestration when applied to land. However, much is still unknown about the chemical and physical biochar characteristics that influence nutrient availability. The objective of this line of study is to determine the effect of biochar application to soils on nutrient availability and C mineralization in relationship to intrinsic biochar properties.