Prospects for management to increase grassland and forage productivity ' 2013 Proceedings of the 22 nd International Grassland Congress 523 Successful establishment of oversown chicory and plantain on uncultivatable hill country Grant B Douglas A , Katherine N Tozer B , Catherine Cameron B , Tom J Fraser C , Paul D Muir D , Ray A Moss C , Grant M Rennie B and Trevor L Knight C A AgResearch, Private Bag 11008, Palmerston North, New Zealand, B AgResearch, Private Bag 3123, Hamilton, New Zealand www.agresearch.co.nz C AgResearch, Private Bag 4749, Lincoln, New Zealand D On-Farm Research, P O Box 1142, Hastings, New Zealand Contact email: grant.douglas@agresearch.co.nz Keywords: Herbs, oversowing, sowing time, aspect, seedling establishment. Introduction All-year grazing of livestock on steep, non-arable hill country (>20 o slope angle, <1,000 m elevation) is a significant feature of New Zealand agriculture. Hill country pastures are in various states of improvement depending on factors such as extent of subdivision, fertiliser inputs, plant species introduction, and grazing management. Numerous introduced grass, legume and herb species are available to match the many micro-sites in steep hill country (Kemp et al. 1999). There has been increasing use of the perennial herbs chicory (Chicorium intybus L.) and plantain (Plantago lanceolata L.) in seed mixtures used on a range of topographies, mostly flat to undulating terrain. Advantages of these species include tolerance of drought and high summer temperatures, highly palatable foliage, enhanced mineral content, and high animal growth rates (Stewart 1996; Li and Kemp 2005). Farmers have sown these species on hill country but there is negligible information on their establishment in such landscapes. As part of a large, New Zealand-wide programme to increase pasture productivity on non-arable hill country through new germplasm introduction, chicory and plantain were included in a seed mixture broadcast-sown at a range of sites. This paper reports on the seedling establishment of these two species. Methods Sites Trials were conducted in four geographically and climatically distinct environments comprising summer wet (Ngaroma, South Waikato; 236 mm average rainfall in summer (December to February)), summer dry (Poukawa, Hawkes Bay; 113 mm), and summer moist (Woodville, southern Hawkes Bay; 177 mm) in the North Island and summer dry (Cheviot, North Canterbury; 127 mm) in the South Island. Average soil water deficits in summer range from 28 mm (Ngaroma) to 45 mm (Cheviot). Sites were selected that had slope angles averaging >20 o and moderate to high soil nutrient status, e.g. pH >5.7, Olsen P > 15 ug/g. Treatments and seed mixture At each site, there was a time of sowing treatment (other treatments not presented) comprising spring 2011 or autumn 2012, which was evaluated on north (N) and south (S) aspects. Chicory cv. Choice (0.5 kg/ha, 92% germinat- ion) and plantain cv. Tonic (0.5 kg/ha, 90%) were the only herbs in a grass/legume/herb seed mixture which was broadcast by hand at 28 kg/ha. On each aspect, treatments were arranged in four randomised complete blocks and plots (experimental units) were 10 m x 10 m. Plots were sprayed with glyphosate (3 litres a.i./ha) 7-10 days before sowing to kill resident swards, and livestock (500 sheep/ha for 3 hrs) were used to trample seed after sowing to increase seed-soil contact. Measurements and analysis Soil temperature (2 cm depth; daily) and volumetric soil water content (VSWC up to 12 cm depth; sowing and every 1-3 weeks) were measured. Seedlings were counted 6 weeks after sowing in 10 x 0.2 m 2 quadrats per plot. Data were expressed as seedlings/m 2 and the percent establishment of each herb species was calculated as percentage of viable seed/m 2 . Data were subject to analysis of variance. Results Across all sites, soil temperature within the first 6-8 weeks after sowing was generally within the range of 15-20 o C in both spring and autumn. For example, in March 2012 on the N aspect, daily temperature averaged 17.8 o at Ngaroma, 19.1 o at Poukawa, 16.4 o at Woodville, and 17.3 o at Cheviot. Temperature was 1-3 o higher on N than S aspects. VSWC exceeded 25% at both sowing times at all of the four sites and at each site, average content across plots on the S aspect was up to 10 percentage units higher than on the N aspect. Seedling density, averaged over all sites, did not vary significantly between spring and autumn for chicory (5 vs. 3/m 2 ) and plantain (6 vs. 4/m 2 ), but there were considerable differences between sites. At Ngaroma and Woodville, seedling density of both species was 4-8-fold higher after