‘MaxClover’ grazing experiment: I. Annual yields, botanical composition and growth rates of six dryland pastures over nine years

Abstract

Six dryland pastures were established at Lincoln University, Canterbury, New Zealand, in February 2002. Production and persistence of cocksfoot pastures established with subterranean, balansa, white or Caucasian clovers, and a perennial ryegrass-white clover control and a lucerne monoculture were monitored for nine years. Total annual dry-matter (10.0-18Á5 t DM ha À1 ) and sown legume yields from the lucerne monoculture exceeded those from the grass-based pastures in all but one year. The lowest lucerne yield (10 t ha À1 yr À1 ) occurred in Year 4, when spring snow caused ungrazed lucerne to lodge and senesce. Cocksfoot with subterranean clover was the most productive grassbased pasture. Yields were 8Á7-13Á0 t DM ha À1 annually. Subterranean clover yields were 2Á4-3Á7 t ha À1 in six of the nine years which represented 26-32% of total annual production. In all cocksfoot-based pastures, the contribution of sown pasture components decreased at a rate equivalent to 3Á3 AE 0Á05% per year (R 2 = 0Á83) and sown components accounted for 65% of total yield in Year 9. In contrast, sown components represented only 13% of total yield in the ryegrasswhite clover pastures in Year 9, and their contribution declined at 10Á1 AE 0Á9% per year (R 2 = 0Á94). By Year 9, 79% of the 6.6 t ha À1 produced from the ryegrasswhite clover pasture was from unsown species and 7% was dead material. For maximum production and persistence, dryland farmers on 450-780 mm yr À1 rainfall should grow lucerne or cocksfoot-subterranean clover pastures in preference to ryegrass and white clover. Inclusion of white clover as a secondary legume component to sub clover would offer opportunities to respond to unpredictable summer rainfall after sub clover has set seed.

Relationships between sheep liveweight production and dry matter yield for lucerne-based pastures in spring

“…This did affect the quantity of spring LWt produced (Figure 4). Cocksfoot is recognised for its competitive behaviour towards companion species (Lee & Cho 1985;Mills et al 2014). In this experiment, once established, cocksfoot suppressed both the lucerne yield on these light soils, and weed encroachment.…”

“…were selected as companion species because of their late-winter/early-spring growth and their potential to increase feed supply in the early-spring pinch period. In contrast, cocksfoot (Dactylis glomerata) was selected as it has previously been shown to be highly persistent in dryland east coast environments (Mills et al 2014) where water stress occurs in most years but varies in duration and severity. It is also commonly used in commercial mixes with lucerne.…”

Bio‐economic efficiency of creep supplementation of forage legumes or concentrate in pasture‐based lamb production system

“…The yield advantage and seasonal complementarity of alfalfa to grass‐clover pastures have been well recognized particularly in environments with dry summers (Brown, Moot, & Pollock, ; Li et al., ; Mills et al., ). In the current study, the herbage growth rates that ranged from 70 to 126 kg DM ha −1 day −1 for alfalfa during the late spring–summer period compared with 48–70 kg DM ha −1 day −1 for irrigated grass‐legume pastures reflected the potential of alfalfa to alleviate the shortage of feed and fulfil the nutritional requirements for finishing lambs in summer.…”

“…Alternatively, complementary feeding with forage legumes may fill the void of summer feed gap with more affordable costs of feeding as compared to concentrates. The capacity of alfalfa ( Medicago sativa ) to provide more consistent growth rates during summer months presents advantages over grass‐clover pastures for sustaining high lamb growth rates under controlled grazing systems (Mills, Lucas, & Moot, , ). Birdsfoot trefoil ( Lotus corniculatus ), a condensed tannin containing legume, has been identified as a potential specialist feed to increase subsequent lambing percentage and lamb growth under commercial dryland farming conditions (Macadam & Griggs, ; Ramirez‐Restrepo et al., ).…”

Pasture production, persistence of legumes and lamb growth in summer‐dry hill pastures

“…the spring of the current study. Similarly, in another dryland pasture study, subterranean clover was reported to be the superior dryland legume when compared to Caucasian clover, balansa clover and white clover sown with orchardgrass in New Zealand (Mills, Lucas, & Moot, 2015). It is probable that using mid-maturing or a combination of early and mid-maturing subterranean clover cultivars with white clover may be more productive in a dry hill site at relatively higher but erratic rainfall conditions.…”