Nutrient Uptake by Warm-Season Perennial Grasses in a Swine Effluent Spray Field

Authors: McLaughlin, Michael; Fairbrother, Timothy; Rowe, Dennis

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/3/2003
Publication Date: 2/1/2004
Citation: McLaughlin, M.R., Fairbrother, T.E., Rowe, D.E. 2004. Nutrient uptake by warm-season perennial grasses in a swine effluent spray field. Agronomy Journal. 96:484-493.

Interpretive Summary: Hay yield and nutrient content were compared among five perennial grasses. Grasses were grown in Mississippi for four years in a swine effluent spray field, which had high levels of soil phosphorus. The grasses were bermudagrass (Common and Coastal), eastern gamagrass, Indiangrass, johnsongrass, and switchgrass. Yield and nutrient content were generally higher in bermudagrass than in the other grasses. Hay yield and nutrient content by common bermudagrass were generally equal to or higher than that of Coastal hybrid bermudagrass. The native well-adapted species, Indiangrass, eastern gamagrass and switchgrass, performed generally as well as or better than johnsongrass, which was the predominant grass in the spray field. With the exception of Indiangrass, which did not produce as much hay as johnsongrass, these native species could be used in the current nutrient management system as alternatives to johnsongrass. All six grasses used nitrogen and phosphorus in amounts that were favorable for minimizing build up of these nutrients in spray field soil. None of the native species, however, yielded as well as bermudagrass. Common bermudagrass offers increased hay production and higher nutrient content than the other grasses tested. Farm managers wishing to establish or improve perennial grass hay systems in southern spray fields should consider common bermudagrass.

Technical Abstract: Haying warm-season forage grasses is a common nutrient management practice on swine lagoon effluent spray fields in the southeastern US. Five warm-season perennial forage grasses, including `Common' and `Coastal' bermudagrass [Cynodon dactylon (L.) Pers.], `PKM-24' eastern gamagrass (Tripsacum dactyloides L.), `Lometa' Indiangrass [Sorghastrum nutans (L.) Nash], johnsongrass [Sorghum halepense (L.) Pers.], and `Alamo' switchgrass (Panicum virgatum L.), were compared for relative dry matter (DM) production and nutrient uptake in a Brooksville silty clay (fine, montmorillonitic, thermic Aquic Chromuderts). Experimental plots were located in an effluent spray field on a swine (Sus scrofa domesticus) farm. Data were collected on DM production and nutrient concentration in 2000-2002. Both bermudagrass varieties produced more forage than the other four grasses in all three years of the study. Common produced from 4.6 to 15.0 Mg DM ha-1 yr-1 and was not significantly different from Coastal (5.2 to 13.7 Mg DM ha-1 yr-1). By comparison, the highest annual DM yields of eastern gamagrass, Indiangrass, johnsongrass, and switchgrass were 9.5, 5.5, 9.7 and 9.1 Mg ha-1 yr-1, respectively. The highest annual uptake of N and P by common and Coastal bermudagrasses, eastern gammagrass, Indiangrass, johnsongrass, and switchgrass 314, 298, 181, 106, 188, and 167 kg N ha-1 yr-1 and 44, 35, 21, 14, 23 and 19 kg P ha-1 yr-1, respectively. The bermudagrass varieties also had higher uptakes of other macronutrients (Ca, K, and Mg) and micronutrients (Cu, Fe, Mn, and Zn).