Productivity and composition of perennial lupin pastures in response to six sowing rates, lime application and lupin type at Glenmore Station, Lake Tekapo

Abstract

This study aims to identify the sowing rate necessary to produce lupin dominant and productive pastures in the New Zealand high country under low-moderate fertility, and a regime of late spring/early summer grazing. Blue and Russell lupin were sown on 12 December 2012 at rates of 2, 4, 8, 12, 16 and 32 kg/ha with cocksfoot at 2 kg/ha, and ± 3 t/ha lime. Low lupin sowing rates (<8 kg/ha) produced an open canopy with lupin density <4 plants/m2, suitable for cocksfoot but also prone to reinvasion by resident species. The blue lupin population was ~5 plants/m2 for sowing rates ≥8 kg/ha. The Russell lupin population was <4 plants/m2 at sowing rates ≤16 kg/ha. Cocksfoot population was 1.3 and 1.9 plants/m2 with blue and Russell lupin, respectively. Dry matter (DM) yield (excluding dead material) was 4.9 t/ha for spring 2014 and 2.1 t/ha for spring 2015, a difference attributed to the low spring rainfall in 2015. Blue lupin contributed more to the total DM yield than did Russell lupin as sowing rates increased. Cocksfoot dominated the remainder of production in spring 2014 but was on a par with resident species production in spring 2015. Summer and autumn regrowth to March 2015 was limited to ~1 kg DM/ha. There was no appreciable regrowth during December 2015 - March 2016. A lupin sowing rate of 8 kg/ha was adequate. Blue lupin population was greater than Russell lupin. Keywords: Lupinus perennis L. polyphyllus, plant density