How will the expanding agriculture business impact wetland graminoids?

As human population increases in the years to come so too will the agriculture business. We already know that the use of chemicals such as fertilizers and other agriculture chemicals aid to promote accelerated crop growth so that we can harvest the most food for the most people. There is less research on the effects that the runoff of these chemicals have on wetland environments that are downstream from farmland. I would like to explore how some of these agricultural chemicals, like ammonium, will affect the growth of different types of wetland graminoids. I will be looking at Poa polustris, Elymus virginicus and carex vulpinoidea