Herbage mass and persistence of pasture legumes and grasses at two potentially different saline and waterlogging sites in northern New South Wales

Abstract

Two adjacent sites (a naturalised pasture and a previously cropped area) with differing potentials for salinity/sodicity and waterlogging near Tamworth, New South Wales were sown with temperate perennial grasses and legumes, temperate annual legumes and tropical perennial grasses to assess their herbage mass and persistence from 2003 to 2006. Plots were either grazed or mown seasonally. Days to flower in the establishment year and seedling regeneration were assessed each year for the annual legumes. In May 2003, salinity levels at soil depths >0.6 m were as high as 8 and 12 dS/m at the naturalised pasture and previously cropped sites, respectively, but generally were >5 and >3 dS/m at a soil depth of 0–0.10 m for these sites in 2004–05. With below average rainfall, no waterlogging was observed at the previously cropped site and only short-term waterlogging of a few days duration occurred at the naturalised pasture site. Under these conditions Puccinellia ciliata cv. Menemen did not establish or perform well, but Thinopyrum ponticum (cvv. Dundas and Tyrrell) was productive and persistent compared with Phalaris aquatica. At both sites, Digitaria eriantha cv. Premier and Chloris gayana cv. Katambora were the best tropical grasses, while the performance of Bothriochloa bladhii subsp. glabra cv. Swann was good at the previously cropped site and Panicum coloratum subsp. makarikariense cv. Bambatsi was best at the naturalised pasture site. At both sites, Medicago sativa had the highest herbage mass and persistence, with cv. Aquarius being superior to cv. Salado after 3 years. Compared with M. sativa, the herbage mass and persistence of Trifolium fragiferum was low. Of the annual legumes, M. polymorpha cv. Scimitar and Melilotus sulcatus had the highest herbage mass.