Introduction, production, and persistence of five grass species in dry hill country

摘要

Grass species were rotary-hoe-drilled into hieracium-dominated fescue tussock. Late autumn and early spring herbage accumulation and composition were determined after three summer grazing treatments (0,6, and 10 weeks freedom from grazing), and two pre-winter grazing managements. Subplots compared species production and persistence at two superphosphate (P) and three nitrogen (N) fertiliser levels. Over the 7 years, sown grasses only occasionally made significant contribution to the sward. #x2018;Grasslands Apanui#x2019; cocksfoot (Dactylis glomerataL.) was the best introduced species, reaching dominance in 66 of subplots receiving P and N in the third year. Ryegrass (Lolium perenneL.) and tall fescue (Festuca arundinaceaSchieb.) made some contribution to sward production, and there were only occasional plants of prairie grass (Bromus willdenowiiKunth) and tall oat grass (Arrenatherum elatius(L.) Beauv. ex J.amp;C. Presl). The principal response was to fertiliser, with alsike clover (Trifolium hybridumL.) responding to P in the early years, and resident fescue tussock (Festuca novae-zealandiae)(Hack.) Ckn, sweet vernal (Anthoxanthum odoratumL.), and browntop (Agrostis copillarisL.) to N in later years. Summer spelling increased March herbage mass but decreased late-autumn growth. Pre-winter lax grazing only slightly increased spring growth.