Production and Resource Use of Winter Feed Crops in New Zealand

In the South Island of New Zealand (NZ), dairy cow numbers have increased from 1.4 to 2.1 million since 2005 (Statistics, New Zealand, 2014). This has led to a strong demand for winter feed crops in place of pasture, and also for supplementing pasture during lactation. Yields of 19–35 t DM/ha are reported for fodder beet (Beta vulgaris L.) in NZ (Chakwizira et al., 2014) compared with 14–25 t DM/ha for forage kale (Brassica oleracea L.) (Chakwizira et al., 2009) and 18–25 t DM/ha for maize (Zea mays L.). Fodder beet has only recently been widely adopted for its ease of feeding and provision a high energy feed (Matthew et al., 2011). Choice of crop is based on yield potential, feed value and suitability for winter feed management. Nitrogen fertiliser and irrigation practices affect the productivity, profitability, and dynamics of resource use during crop growth; and losses of N during winter in situ feeding. Optimized systems with high water and N use efficiency are sought to reduce potential adverse environmental effects. The objectives were to compare efficiency of water and N use of fodder beet, kale and maize and assess their value to growers

Sowing Date Affects Dry Matter Yield of Fodder Beet (\u3ci\u3eBeta vulgaris\u3c/i\u3e L.) Crops and Farm Profitability

Fodder beet (Beta vulgaris L.) is a high yielding and high energy supplementary ruminant feed. Including the crop in a pasture system means loss in production and additional costs during crop establishment, but economic benefits may be recovered with increased seasonal productivity and feed quality. In this study, the Agricultural Production Systems sIMulator was used to estimate herbage production of a typical dairy farm in the Canterbury region of New Zealand based on using a ryegrass (Lolium perenne L.)-clover (Trifolium repens L.) pasture (“Pasture only”) or pasture in combination with fodder beet as winter feed (“Pasture+Fodder beet (FB)”). Mean yields of pasture were used to estimate the potential pasture yield lost from spraying out paddocks 1 month before establishing fodder beet. Fodder beet (‘Rivage’) yields from a 2014 sowing date trial: 19 September (Sep-FB), 17 October (Oct-FB), 17 November (Nov-FB), and 15 December (Dec-FB) were used. Dry matter (DM) yield was determined on 15 June 2015. Yield was 27 t DM/ha for both Sep-FB and Oct-FB and was reduced by 23 and 32% in Nov-FB and Dec-FB, respectively. The total annual yield for “Pasture only” was 16.7 t DM/ha compared with adjusted yield of 29.5, 30.2, 25.7 and 24.9 t DM/ha for “Pasture+Sep-FB”, “Pasture+Oct-FB”, “Pasture+Nov-FB” and “Pasture+Dec-FB”, respectively. Production cost was NZ$0.08/kg DM each for “Pasture+Sep-FB” and “Pasture+Oct-FB”, which was lower than NZ$0.09/kg DM for “Pasture only”. Production costs increased to NZ$0.11/kg DM for “Pasture+Nov-FB” and NZ$0.12/kg DM for “Pasture+Dec-FB”, but revenue from sale of surplus feed partially offset these costs. Our results show that sowing in October was the most profitable option. Yield gains from sowing fodder beet in September are unlikely because of low temperatures limiting crop growth. Delaying sowing can increase production costs and yield penalty, but potential returns are greater, compared with “Pasture only”

Options for Improved Biomass Production in Feeding Systems for Dairying in High Rainfall Environments in New Zealand

New Zealand dairy production has expanded into marginal climates and soil types on the premise of excellent profitability and efficient utilisation of forage. Annual pasture production in the cool West Coast of the South Island (rainfall 2042-2933 mm) is15,000 kg. Increased farm production and feeding of high quality biomass, from imported feed or supplementary feed crops grown on- farm, are needed to improve milk solid output. Small plot trials with spring and early summer-sown brassicas, cereals and maize were the focus for development of systems to maximise and manage the seasonal feed supply. The effect of sowing time, fertiliser timing and rate of N and K fertiliser application were studied to quantify the risks of crop failure in the high rainfall and low radiation environment. The aim was to increase forage supply/ha in a predominantly grass-based system and reduce associated risks to environmental sustainability

Irrigation Management Strategies for Fodder Beet (\u3ci\u3eBeta vulgaris\u3c/i\u3e L.) Crops

The production of fodder beet (Beta vulgaris L.) in New Zealand is concentrated in the South Island, and often requires irrigation to achieve high yields. Development of efficient irrigation management strategies requires information on the effect of timing and rate of irrigation on crop growth. A field study was conducted on a moderately deep soil at Chertsey, Canterbury, New Zealand, to evaluate crop growth responses to five irrigation managements: Rain-fed (control), weekly replacement of full evapotranspiration (FullET-weekly), and 50% of evapotranspiration replaced weekly (HalfET-weekly), fortnightly (HalfET-2weekly) or 3-weekly (HalfET-3weekly). Irrigation to replace ET was adjusted to account for rainfall received between irrigation events. The crop was sown on 11 October 2015. Dry matter (DM) and green leaf area index (LAI) were quantified at 4-weekly intervals from 21 December 2015 until 16 May 2016. Water use efficiency (WUE) was calculated from weekly time domain reflectometry and neutron probe measurements of volumetric soil water content (to 0.8 m depth) and crop biomass. Final yield was lowest for Rain-fed (17.1 t DM/ha) and highest for FullET-weekly (28.9 t DM/ha) treatments. The remaining treatments did not differ in yield, producing 22.4±1.6 t DM/ha, but differed significantly from the Rain-fed and FullET-weekly treatments. Yield differences were associated with the rate of leaf area expansion and duration of critical LAI values (≥ 3.0 m2/m2), which were greater for FullET-weekly than for other treatments. Rain-fed and FullET-weekly treatments resulted in the highest and lowest WUE (81 versus 47 kg DM/ha/mm). The remaining treatments did not differ in WUE, averaging 67±3.6 kg DM/ha/mm. Our results show yield benefits from irrigation, with the best outcome from FullET-weekly given the soil type and weather conditions. However, under water restriction conditions, the HalfET-3weekly management is recommended over more frequent partial ET replacements because it would reduce irrigation costs without penalising yield

Detecting inconsistent responding on the youth psychopathic traits inventory-short form

The Youth Psychopathic Traits Inventory-Short Form (YPI-S) is a convenient measure for assessing psychopathy in settings with constraints on resources. However, the YPI-S does not contain a means of detecting careless or random response styles. The present study describes the development and evaluation of an inconsistent responding scale for the YPI-S using five archival samples that vary in language (English, German, Italian, Dutch) and other participant characteristics (juvenile offenders, adolescent students). Inconsistency scores resulting from the new scale effectively distinguished genuine participant responses from randomly generated cases (area under the ROC curve [AUC] = .85-.90) and from cases in which 50% of original responses were replaced with random data (AUC = .75-.82). The associations between the YPI-S and theoretically relevant correlates were reduced among participants exceeding proposed cutoff scores for profile validity compared with associations among more consistent respondents

Homo Naledi, A New species of the Genus Homo from the Dinaledi Chamber, South Africa

Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is characterized by body mass and stature similar to small-bodied human populations but a small endocranial volume similar to australopiths. Cranial morphology of H. naledi is unique, but most similar to early Homo species including Homo erectus, Homo habilis or Homo rudolfensis. While primitive, the dentition is generally small and simple in occlusal morphology. H. naledi has humanlike manipulatory adaptations of the hand and wrist. It also exhibits a humanlike foot and lower limb. These humanlike aspects are contrasted in the postcrania with a more primitive or australopith-like trunk, shoulder, pelvis and proximal femur. Representing at least 15 individuals with most skeletal elements repeated multiple times, this is the largest assemblage of a single species of hominins yet discovered in Africa

23 High Redshift Supernovae from the IfA Deep Survey: Doubling the SN Sample at z>0.7

We present photometric and spectroscopic observations of 23 high redshift supernovae spanning a range of z=0.34-1.03, 9 of which are unambiguously classified as Type Ia. These supernovae were discovered during the IfA Deep Survey, which began in September 2001 and observed a total of 2.5 square degrees to a depth of approximately m=25-26 in RIZ over 9-17 visits, typically every 1-3 weeks for nearly 5 months, with additional observations continuing until April 2002. We give a brief description of the survey motivations, observational strategy, and reduction process. This sample of 23 high-redshift supernovae includes 15 at z>0.7, doubling the published number of objects at these redshifts, and indicates that the evidence for acceleration of the universe is not due to a systematic effect proportional to redshift. In combination with the recent compilation of Tonry et al. (2003), we calculate cosmological parameter density contours which are consistent with the flat universe indicated by the CMB (Spergel et al. 2003). Adopting the constraint that Omega_total = 1.0, we obtain best-fit values of (Omega_m, Omega_Lambda)=(0.33, 0.67) using 22 SNe from this survey augmented by the literature compilation. We show that using the empty-beam model for gravitational lensing does not eliminate the need for Omega_Lambda > 0. Experience from this survey indicates great potential for similar large-scale surveys while also revealing the limitations of performing surveys for z>1 SNe from the ground.Comment: 67 pages, 12 figures, 12 tables, accepted for publication in the Astrophysical Journa

On the fate of the secondary white dwarf in double-degenerate double-detonation Type Ia supernovae

The progenitor systems and explosion mechanism of Type Ia supernovae are still unknown. Currently favoured progenitors include double-degenerate systems consisting of two carbon-oxygen white dwarfs with thin helium shells. In the double-detonation scenario, violent accretion leads to a helium detonation on the more massive primary white dwarf that turns into a carbon detonation in its core and explodes it. We investigate the fate of the secondary white dwarf, focusing on changes of the ejecta and observables of the explosion if the secondary explodes as well rather than survives. We simulate a binary system of a $1.05\,M_\odot$ and a $0.7\,M_\odot$ carbon-oxygen white dwarf with $0.03\,M_\odot$ helium shells each. We follow the system self-consistently from inspiral to ignition, through the explosion, to synthetic observables. We confirm that the primary white dwarf explodes self-consistently. The helium detonation around the secondary white dwarf, however, fails to ignite a carbon detonation. We restart the simulation igniting the carbon detonation in the secondary white dwarf by hand and compare the ejecta and observables of both explosions. We find that the outer ejecta at $v>15000\,\mathrm{km\,s^{-1}}$ are indistinguishable. Light curves and spectra are very similar until $\sim 40$d after explosion and the ejecta are much more spherical than for violent merger models. The inner ejecta differ significantly which slows down the decline rate of the bolometric light curve after maximum of the model with a secondary explosion by about 20 per cent. We expect future synthetic 3D nebular spectra to confirm or rule out either model.Comment: 12 pages, 7 figures, submitted to MNRAS, comments welcom