Good Fertility in Tall Fescue Pasture
Cristie Preston, Ph.D.
Agriculture has always been an integral part of Dr. Cristie Preston’s life. She grew up in southwest Virginia and had interest in crop and animal agriculture since an early age. Once she began college, she initially chose to study animal science but switched to soil science. Dr. Preston attributes her decision partly to an influential professor who told her, “You can’t understand animals until you understand what they eat.” She received a Bachelor of Science degree in animal science and a Master of Science degree in crop and soil environmental science from Virginia Tech. Dr. Preston holds a Ph.D. in agronomy, focusing on soil fertility from Kansas State University. While completing her advanced degrees, Dr. Preston conducted more than six years of field and lab research. Dr. Preston has experience in laboratory research measuring volatility loss from urea-based fertilizers. Her field research has focused on phosphorus availability and the interactions with tillage and placement. She also has extensive experience in working with large data sets and analysis. Her main priority is helping growers to identify yield-limiting factors and fix those issues as cost efficiently as possible.
When it comes to many tall fescue pastures in the Midwest, the presence of broomsedge – a native perennial and invasive species in pasture – can be a sign of low phosphorus. Whether those levels are actually low or merely unavailable due to a low soil pH, tall fescue yield and quality can be negatively affected by high amounts of broomsedge.
A recent article in Crop, Forage, and Turfgrass Management looked at the additions of phosphorus, lime, and their combination to tall fescue pastures to discourage broomsedge growth. A single phosphorus application of 50 pounds per acre was applied in the first year. Broomsedge presence was assessed every year for three years.
Phosphorus application decreased broomsedge stand percentage and increased tall fescue percentage. Similarly, lime application had the same impact. Applying both lime and phosphorus produced the best outcome – minimizing broomsedge and maximizing tall fescue percentage.