Can Lotus pedunculatus over-sowing in low-fertility tussock country increase farm resilience?

The range of legumes to boost farm productivity in low-fertility hill country are limited. Lotus pedunculatus (Lotus) provides an option when soil pH is below 5 but is intolerant to severe and regular grazing. However, itcan be used at sites that are only grazed occasionally during spring summer and autumn. Oversowing of Lotus pedunculatus has been used to improve 17% of the total area of Avenel Station, Millers Flat. Measurements of pasture growth and animal production were collected over three years post-sowing, indicating a doubling of pasture production from the native form while providing liveweight gains of 0.135 and 0.75 kg/d in lambs and yearling cattle respectively. Systems modelling was used to re-examine the current farm-system configuration to test the possible outcomes from implementing further enterprises that may capture the increased late spring and summer production effectively. Reducing ewe numbers and concentrating on improving lamb survival were the most cost-effective and environmentally effective options. Buying in further finishing lambs to use the summer surplus also improved profitability. Increasing cow numbers was similarly profitable. Increasing ewe numbers also required an increase in winter feed supply and was the least profitable way to capture the benefits. Testing using climatic extreme scenarios demonstrated that the oversowing of Lotus on the higher, wetter tussock country increased the resilience of the farm by providing a buffer during dry summers.

Dry matter yield of six perennial legume species in response to lime over 3 years at Glenmore Station, Mackenzie Basin

The production and persistence of legumes which may improve South Island high-country pasture in the Mackenzie Basin were studied. The initial soil test results confirmed toxic levels of aluminium (9 mg/kg, 0-150 mm soil depth) that has prevented the development of large areas of land traditionally grazed by merino sheep and beef cattle. A 3-year field experiment was direct-drilled in December 2012 with five rates (0, 0.5, 1, 2, and 4 t/ha) of surface applied lime and six legumes (lucerne, ‘Russell’ lupin, Caucasian clover, white clover, balansa, and Lotus pedunculatus) in three replicates. In Year 1, balansa clover and Russell lupin were the highest yielding legumes (7 t DM/ha), regardless of lime application rates. In Year 2 ‘Russell’ lupin was the highest (10.4 t DM/ha). Caucasian clover produced 4.6 t DM/ha and white clover and lucerne around 4.0 t DM/ha. Balansa clover (1.4 t DM/ha) and Lotus pedunculatus (2.5 t DM/ha) were the lowest yielding and they did not recover or persist after the initial grazing by merino sheep. These results confirmed that ‘Russell’ lupin and Caucasian clover thrived without the application of lime in this acidic soil with high Al levels.

Red clover - a legume showing tolerance to clover root weevil

Clover root weevil (CRW) has now spread through the northern North Island, and south into Taranaki and Hawke's Bay r egions. Sever e infestations can decimate white clover in pasture. In 1998, 2000 and 2002, trials were estab lished on a Warkworth Northland dairy farm to test a range of legume species for resistance or tolerance to CRW damage. Trial lines were regularly assessed for relative vigour and levels of CRW damage. No plant resistance w as identified among white clover, red clover, lucerne, Lotus corniculatus, Lotus pedunculatus or Caucasian clover seed lines. A few lines were adapted to the site and showed tolerance to CRW. Red clover suf fered the least damage and tolerant selections were made from a creeping red clover and nine white clover lines. Two further trials confirmed that red clover showed the least damage. Further cycles of selection are required to develop the potential tolerance shown in field tests. Red clover or a well-adapted white clover offers potential to cope with the CRW stress. Keywords: clover root weevil, clover selections, legume tolerance, Sitona lepidus

Legume groundcovers have mixed effects on growth and yield ofMacadamia integrifolia

The effects of Lotus pedunculatus (cv. Grasslands Maku) and Arachis pintoi (cv. Amarillo) groundcovers on growth and yield of 1-, 4- and 14-year-old macadamia orchards were investigated over 5 years near Lismore in northern New South Wales. Bare control plots were used at all sites, along with an unmown groundcover in the oldest orchard. Vegetative growth was assessed in terms of shoot extension, trunk diameter and canopy volume. The groundcovers had the greatest effect on vegetative growth of the trees when they were established into an existing sward, followed by the 4-year-old trees, and then the 14-year-old trees. Yields were collected from the 4- and 14-year-old trees and were generally similar under bare soil or groundcovers, with smaller or similar canopy volumes. Nut quality was not consistently affected by the groundcovers, whereas nut-drop was delayed. Acceptable yields can be obtained in macadamias with groundcovers, with potential benefits in terms of soil structure, fertility and stability. Mown and unmown plots have similar productivity.

The effect of herbage allowance of Lotus pedunculatus cv. Grasslands Maku on winter and spring beef heifer performance

Beef cattle production in Uruguay is limited by heifer mating age when grazing natural pastures. Lotus pedunculatus cv. Grasslands Maku is a forage species that was recently introduced to Uruguayan farming systems, with high potential to improve herbage production in acid and low fertility soils. This paper provides information about winter and spring performance of Hereford x Angus heifers grazing an improved Lotus pedunculatus cv. Grasslands Maku pasture when fed at different pasture allowances. Four pasture allowances (3, 5, 10 and 16 kg DM/100 kg animal liveweight/day) from June 30 to October 9 (P1) followed by one pasture allowance of 9 kg DM/100 kg animal liveweight/day from October 9 to November 28 (P2), were assigned to 9 months old Hereford x Angus heifers weighing 129 kg. Measurements included herbage mass, botanical composition, pasture growth rate, sward height and animal liveweight. Liveweight gains were evaluated using a repeated measurement model in time. Pasture mass decreased from 4000 kg DM/ha to 1100, 1050, 1350 and 2000 kg DM/ha for the herbage allowances of 3, 5, 10 and 16% respectively during P1. Legume content at the end of P1 was 550, 400, 700 and 700 kg DM/ha for 3, 5, 10 and 16% of total pasture mass respectively. Herbage mass increased by 328 kg DM/ha per cm sward height (P

Methanogenesis from forages fed to sheep

Methane production has been measured from lambs fed contrasting forages. This work has been driven by the need to reduce greenhouse gas emissions from agriculture and to determine energy losses to methane from contrasting diets. Young ram lambs were fed either fresh ryegrass/white clover pasture, lucerne (also pelleted lucerne), sulla, chicory, red clover, Lotus pedunculatus (lotus) and mixtures of sulla and lucerne, sulla and chicory and chicory with red clover. The effects of condensed tannin (CT) in lotus on methane production were also measured. The trials were carried out indoors with sheep held in metabolism crates to enable an accurate measurement of intake and digestibility as well as methane production. Principal findings were a two-fold range in emissions from 11.5g CH4/kg dry matter intake (DMI) with lotus to 25.7g CH4/kg DMI with pasture and a 16% reduction in methane production due to the CT in lotus. This range in emissions from good quality forages represents a loss of about 7-11% of metabolisable energy and presents a clear direction for future research to better utilise the feeding value of pastures and reduce greenhouse gas (GHG) emissions from agriculture. High quality perennial forages should be used where practical, and researchers need to identify plant parameters responsible for the variation in methane emissions. Research must focus on rapid passage of digesta through the rumen of grazing animals and will involve manipulation of the fibre content of grasses. Introduction of CT into diets is a likely target to reduce methane production. Improving the rapidly digestible constituents of forages is another opportunity, but difficult to target. Keywords: condensed tannins, forage quality, forages, greenhouse gases, methane emissions, sheep

Influence of condensed tannins on gut morphology in sheep fed Lotus pedunculatus

Feeding forages containing condensed tannins (CT) can reduce intestinal absorption of amino acids (AA) and peptides. This experiment tested the hypothesis that CT in Lotus pedunculatus altered small intestinal mucosal morphology reducing absorptive capacity of the gut. Thirteen young Romney wethers were fed ad libitum either Lotus pedunculatus (cv. Grasslands Maku, N = 7) containing 5.5% CT in the dry matter (DM) or white clover-perennial ryegrass pasture (N = 6), which did not contain CT, for 4 wk. The wethers were euthanized at the end of the feeding trial and samples were collected for histological examination from the proximal and distal duodenum, proximal, mid-, and distal jejunum and ileum, and ventral rumen. There was no effect of feeding L. pedunculatus containing 5.5% CT (P > 0.05) on rumen or gut morphological parameters in sheep. The cause of reduced AA absorption in the presence of CT is not known, but this study suggests it is not due to changes in intestinal morphology. Key words: Lotus pedunculatus, condensed tannins, gut morphology, sheep