Persistence of Alfalfa Sod‐Seeded into Bermudagrass Pastures on Coastal Plain Soils

Abstract

Alfalfa (Medicago sativa L.) production and persistence in the Lower South of the USA are dependent on climate, soil, and competition from warm‐season perennial grasses such as bermudagrass [Cynodon dactylon (L.) Pers.]. A 3‐year study was conducted at Texas A&M AgriLife Research, Overton, to evaluate ‘Alfagraze’ alfalfa persistence on a Darco loamy fine sand (loamy, siliceous thermic Grossarenic Paleudult) when sod‐seeded at three row spacings (10, 20, and 30 inches) into a well‐established ‘Coastal’ bermudagrass pasture. Alfagraze was rotationally stocked with animal residence time from 5 to 13 d and deferment periods ranging from 18 to 27 d. In Year 1, during the first three grazing periods (1 April to 31 May), alfalfa was the dominant species (P < 0.05). Thereafter, from 30 June to 3 October, bermudagrass was dominant (P < 0.05). At the initiation of harvest in Year 2 (1 April), alfalfa dry matter (DM) was 1353, 783, and 690 lb/acre, respectively, at 10‐, 20‐, and 30‐inch drill‐row spacing prior to bermudagrass growth. At the end of Year 2 (3 October), alfalfa DM was 33, 10, and 0.90 lb/acre, respectively, at 10‐, 20‐, and 30‐inch spacings while bermudagrass DM was 1424, 1557, and 1080 lb/acre. At the beginning of Year 3, the percent stands of alfalfa were 14, 11, and 5%, respectively, for 10‐, 20‐, and 30‐inch spaced alfalfa plantings, while the respective percent stands of bermudagrass were 86, 89, and 95%. Under the climatic and sandy Coastal Plains soils of this vegetation region, Alfagraze was not persistent under grazing at any row spacing for more than 3 years when sod‐seeded into a well‐established Coastal bermudagrass pasture.