About me

Hello! My name is Huong Nguyen. I am a postdoctoral associate with Dr. Matt Ryan at the Sustainable Cropping Systems Lab. I earned my Ph.D. in Sustainable Agriculture at Iowa State University with Dr. Matt Liebman.

I am working on implementing cover crops in organic cropping systems in northeastern USA.

In Vietnam, where I grew up, weeds (or wild plants) are widely used as additional animal feedstock, homeopathic remedies for common illnesses, and in traditional beauty products. Seeing how weeds are conventionally managed in the United States was shocking when I first came to graduate school. My graduate research focused on the effects of cropping system diversification on common waterhemp control in an integrated pest management context. Common waterhemp is a noxious weed species found throughout Midwestern croplands that thrives, competes with crops, produces many seeds, and maintains a persistent soil seedbank that insures recurring infestations. My primary goal was to identify sustainable practices to deplete waterhemp’s soil seedbank while not compromising crop yields and environmental quality. One cropping system in our experiment was a four-year rotation in the following sequence: corn-soybean-oat interseeded with alfalfa – alfalfa. The alfalfa that was interseeded with oat in the third year was maintained over winter to the fourth year of the rotation. The weed management and cropping system diversification strategies were ecologically driven, considering natural resource availability and potential markets for the added crops. Oat and alfalfa exude allelopathic chemicals against weed seedlings. Interseeding alfalfa with oat in the third year of the rotation reduces the soil disturbance frequency, and the alfalfa hosts beneficial insects over winter. My preliminary model suggested that the waterhemp seedbank density is declining the fastest in one of the diversified cropping systems while using 60% less herbicide than in the conventional system. Crop yields in the more diverse rotations were higher than those in the baseline system. The 4-year system’s sustainability is improved as the total amount of herbicide’s active ingredient is reduced by 80%, significantly reducing freshwater toxicity load and greenhouse gas emissions. Higher weed seedbank diversity and richness in the 4-year rotation are coincident with improved cropping system sustainability.