Nutrient Uptake of Swine Effluent-Fertilized Bermudagrass During Primary Spring and Summer Growth

Abstract

ABSTRACT Production of bermudagrass [Cynodon dactylon (L.) Pers.] hay to manage manure nutrients may differ from production of hay intended for livestock consumption. The objective of this study was to determine the relationships between maturity and yield, nutrient concentration, and nutrient uptake in bermudagrass fertilized with swine effluent. Primary spring and summer growth of ‘Coastal’ hybrid and common bermudagrass was harvested every 7 d to 63 d maturity. Effluent applied to Brooksville silty clay loam (fine, smectitic, thermic Aquic Hapludert) during each harvest period contained 140 kg nitrogen (N), 240 kg potassium (K), and 25 kg phosphorus (P) ha− 1 (mean of 2 years). Coastal and common bermudagrass had similar trends for yield, nutrient concentration, and nutrient uptake. Dry-matter production followed a linear trend in the spring (maximum of 1.11kg m− 2 after 63 d) and a quadratic trend in the summer (maximum of 0.96 kg m− 2 after 56 d). Herbage N concentration declined from 33 to 17 g kg− 1 during the spring and summer harvest period, while P concentration declined from 3.8 to 2.4 g kg− 1. Maximum K concentration (26 g kg− 1) occurred at 28 d of growth. Nitrogen, P, and K uptake exhibited a quadratic response to increasing maturity during the spring and summer harvest periods, but maximum uptake was greater in the spring than in the summer. These results suggest that the spring harvest period is the best time to maximize nutrient uptake by delaying bermudagrass harvest to more mature stages.