Perennial pastures for recharge control in temperate drought-prone environments. Part 1: productivity, persistence and herbage quality of key species

Abstract

Perennial-based pasture swards potentially offer land managers the capacity for recharge control in temperate cropping zone environments to satisfy the dual role of fostering increased agricultural productivity and reduced deep drainage. This study evaluated the productivity, persistence and herbage quality of lucerne (Medicago sativa L.), phalaris (Phalaris aquatica L.), chicory (Cichorium intybus L.), perennial veldt grass (Ehrhata calcycina Sm.), grazing brome (Bromus stamineus E. Desv.), plantain (Plantago lanceolata L.), Rhodes grass (Chloris gayana Kunth), tall fescue (Festuca arundinacea syn. Lolium arundinaceum Schreb. syn. Schedonorus phoenix (Scop.) Holub.) and cocksfoot (Dactylis glomerata L.) in two contrasting environments in the cropping zone of southern New South Wales (NSW), Australia. The performance of two cultivars with contrasting levels of summer activity of each of the latter two species was also assessed. Lucerne was the most productive species evaluated, producing 54–85% more herbage than phalaris, the next most productive species. Lucerne was also the most persistent species with a higher basal frequency than all other species during the experimental period and, averaged across samplings, had the highest crude protein (22.3%) in the leaf and stem of any species. Chicory herbage had the highest dry matter digestibility (76.7%) and ash content (15.1%) and lowest neutral (35.4%) and acid detergent fibre contents (21.8%) compared with the other species. The more summer-dormant cultivars of cocksfoot (cv. Kasbah) and tall fescue (cv. Fraydo) were both found to be more persistent than their semi-summer-active counterparts (cvv. Currie and Demeter, respectively), demonstrating the importance of summer dormancy for the persistence of both species in these environments. Tall fescue cv. Fraydo was equally persistent yet produced only 42–51% of the cumulative biomass of phalaris over 5 years, indicating that tall fescue is not a viable species in these drought-prone environments, nor were plantain and grazing brome due to their inferior productivity and persistence. The study highlighted the lack of viable perennial pasture options currently available in cropping zone environments of southern NSW other than lucerne, phalaris and the summer-dormant cultivar of cocksfoot, Kasbah. Chicory and perennial veldt grass, with further breeding and selection under Australian environmental conditions, could have the potential to be viable perennial pasture options for the cropping zone of southern NSW.