Net nitrogen balances for cool-season grain legume crops and contributions to wheat nitrogen uptake: a review

2001 ◽  
Vol 41 (3) ◽  
pp. 347 ◽  
Author(s):  
J. Evans ◽  
A. M. McNeill ◽  
M. J. Unkovich ◽  
N. A. Fettell ◽  
D. P. Heenan

The removal of nitrogen (N) in grain cereal and canola crops in Australia exceeds 0.3 million t N/year and is increasing with improvements in average crop yields. Although N fertiliser applications to cereals are also rising, N2-fixing legumes still play a pivotal role through inputs of biologically fixed N in crop and pasture systems. This review collates Australian data on the effects of grain legume N2 fixation, the net N balance of legume cropping, summarises trends in the soil N balance in grain legume–cereal rotations, and evaluates the direct contribution of grain legume stubble and root N to wheat production in southern Australia. The net effect of grain legume N2 fixation on the soil N balance, i.e. the difference between fixed N and N harvested in legume grain (Nadd) ranges widely, viz. lupin –29–247 kg N/ha (mean 80), pea –46–181 kg N/ha (mean 40), chickpea –67–102 kg N/ha (mean 6), and faba bean 8–271 kg N/ha (mean 113). Nadd is found to be related to the amount (Nfix) and proportion (Pfix) of crop N derived from N2 fixation, but not to legume grain yield (GY). When Nfix exceeded 30 (lupin), 39 (pea) and 49 (chickpea) kg N/ha the N balance was frequently positive, averaging 0.60 kg N/kg of N fixed. Since Nfix increased with shoot dry matter (SDM) (21 kg N fixed/t SDM; pea and lupin) and Pfix (pea, lupin and chickpea), increases in SDM and Pfix usually increased the legume’s effect on soil N balance. Additive effects of SDM, Pfix and GY explained most (R2 = 0.87) of the variation in Nadd. Using crop-specific models based on these parameters the average effects of grain legumes on soil N balance across Australia were estimated to be 88 (lupin), 44 (pea) and 18 (chickpea) kg N/ha. Values of Nadd for the combined legumes were 47 kg N/ha in south-eastern Australia and 90 kg N/ha in south-western Australia. The average net N input from lupin crops was estimated to increase from 61 to 79 kg N/ha as annual rainfall rose from 445 to 627 mm across 3 shires in the south-east. The comparative average input from pea was 37 to 47 kg N/ha with least input in the higher rainfall shires. When the effects of legumes on soil N balance in south-eastern Australia were compared with average amounts of N removed in wheat grain, pea–wheat (1:1) sequences were considered less sustainable for N than lupin–wheat (1:1) sequences, while in south-western Australia the latter were considered sustainable. Nitrogen mineralised from lupin residues was estimated to contribute 40% of the N in the average grain yield of a following wheat crop, and that from pea residues, 15–30%; respectively, about 25 and 15 kg N/ha. Therefore, it was concluded that the majority of wheat N must be obtained from pre-existing soil sources. As the amounts above represented only 25–35% of the total N added to soil by grain legumes, the residual amount of N in legume residues is likely to be important in sustaining those pre-existing soil sources of N.

Zootaxa ◽  
2007 ◽  
Vol 1645 (1) ◽  
pp. 57-61 ◽  
Author(s):  
LAURENCE A. MOUND ◽  
ALICE WELLS

Callococcithrips gen.n. is erected for the species Rhynchothrips fuscipennis Moulton that lives only among the protective waxy secretions of an eriococcid on Kunzea in south-eastern Australia. Larvae and adults of this thrips move rapidly amongst the sticky wax strands, and their maxillary stylets are unusually long and convoluted. Circumstantial evidence suggests that the thrips is predatory on immature stages of the eriococcid. Also transferred to this genus is Liothrips atratus Moulton, based on a single female from Western Australia.


1996 ◽  
Vol 36 (6) ◽  
pp. 701 ◽  
Author(s):  
CP Horn ◽  
RC Dalal ◽  
CJ Birch ◽  
JA Doughton

Following long-term studies at Warra, on the western Darling Downs, chckpea (Cicer anetinum) was selected as a useful grain legume cash crop with potential for improvement of its nitrogen (N) fixing ability through management. This 2-year study examined the effect of sowing time and tillage practice on dry matter yield, grain yield (Horn et al. 1996), N accumulation, N2 fixation, and the subsequent soil N balance. Generally, greater N accumulation resulted from sowing in late autumn-early winter (89-117 kg N/ha) than sowing in late winter (76-90 kg N/ha). The amount of N2 fixed was low in both years (15-32 kg N/ha), and was not significantly affected by sowing time or tillage. The potential for N2 fixation was reduced in both years due to high initial soil nitrate levels and low total biomass of chickpea because of low rainfall. Nitrogen accumulation by grain was higher under zero tillage (ZT) than conventional tillage (CT) for all sowing times, and this affected the level of grain N export. The consequence of low N2 fixation and high N export in chickpea grain was a net loss of total soil N, (2-48 kg N/ha under CT and 22-59 kg N/ha under ZT). Management practices to ensure larger biomass production and lower soil nitrate-N levels may result in increased N2 fixation by chickpea and thus a positive soil N balance.


2009 ◽  
Vol 49 (10) ◽  
pp. 759 ◽  
Author(s):  
Andrew D. Moore

Dual-purpose cereals are employed in the high-rainfall zone of southern Australia to provide additional winter forage. Recently there has been interest in applying this technology in the drier environments of South and Western Australia. It would therefore be useful to gain an understanding of the trade-offs and risks associated with grazing wheat crops in different locations. In this study the APSIM (Agricultural Production Systems Simulator) crop and soil simulation models were linked to the GRAZPLAN pasture and livestock models and used to examine the benefits and costs of grazing cereal crops at 21 locations spanning seven of the regions participating in the Grain & Graze research, development and extension program. A self-contained part of a mixed farm (an annual pasture–wheat rotation plus permanent pastures) supporting a breeding ewe enterprise was simulated. At each location the consequences were examined of: (i) replacing a spring wheat cultivar with a dual-purpose cultivar (cv. Wedgetail or Tennant) in 1 year of the rotation; and (ii) either grazing that crop in winter, or leaving it ungrazed. The frequency of early sowing opportunities enabling the use of a dual-purpose cultivar was high. When left ungrazed the dual-purpose cultivars yielded less grain on average (by 0.1–0.9 t/ha) than spring cultivars in Western Australia and the Eyre Peninsula but more (by 0.25–0.8 t/ha) in south-eastern Australia. Stocking rate and hence animal production per ha could be increased proportionately more when a dual-purpose cultivar was used for grazing; because of the adjustments to stocking rates, grazing of the wheat had little effect on lamb sale weights. Across locations, the relative reduction in wheat yield caused by grazing the wheats was proportional to the grazing pressure upon them. Any economic advantage of moving to a dual-purpose system is likely to arise mainly from the benefit to livestock production in Western Australia, but primarily from grain production in south-eastern Australia (including the Mallee region). Between years, the relationship between increased livestock production and decreased grain yield from grazing crops shifts widely; it may therefore be possible to identify flexible grazing rules that optimise this trade-off.


1993 ◽  
Vol 7 (6) ◽  
pp. 1473 ◽  
Author(s):  
RV Southcott

Larval Leptus (Acarina : Erythraeidae) ectoparasitic on higher insects (Neuroptera. Coleoptera. Lepidoptera. Hymenoptera) are comprehensively reviewed (Diptera were considered previously) . The new species (all from Australia) comprise: L. spinalatus (from Neuroptera); L. belicolus. L. cerambycius. L. faini. L. halli. L. heleus. L. jenseni. L. orthrius. L. tarranus. L. titinius. L. truncatus. L. utheri (all from Coleoptera); L. agrotis, L. georgeae (from Lepidoptera); and L. monteithi (from Hymenoptera). A key is given to the larvae of Leptus from Australia and New Guinea . L. agrotis is an ectoparasite of Agrotis infusa (Boisduval), the bogong moth, whose larvae are an important pasture pest in south-eastern Australia; as well as the larva, the deutonymph and adult are described. Leptus boggohoranus Haitlinger is recorded from a further New Guinea species of Coleoptera. L. charon Southcott, originally described from an Australian dipteran, is recorded as ectoparasitic on an Australian larval lepidopteran (Anthela sp., Anthelidae), as well as from adult Lepidoptera and Coleoptera. Leptus trucidatus (Hull, 1923), comb. nov., is proposed for Achorolophus trucidatus Hull, 1923, an adult from Western Australia.


2012 ◽  
Vol 25 (1) ◽  
pp. 49 ◽  
Author(s):  
Robert Gibson ◽  
Barry J. Conn ◽  
Jeremy J. Bruhl

A phenetic study of morphological characters of the Drosera peltata complex (Droseraceae) supports the recognition of the following taxa: D. peltata from wetlands of south-eastern Australia; D. auriculata from south-eastern Australia and New Zealand; the morphologically variable D. hookeri from south-eastern Australia and northern New Zealand; the widespread D. lunata from southern and South-East Asia, as well as northern and north-eastern Australia; and the new species D. yilgarnensis R.P.Gibson & B.J.Conn is here described, from around granite outcrops of south-western Australia. D. bicolor from south-western Australia is recognised as a distinct species outside of the D. peltata complex. D. insolita, considered until recently as a distinct species, is reduced to synonymy of D. lunata. Phenotypic plasticity, vegetative similarity and fleetingly produced diagnostic floral and seed characters within the complex pose significant challenges in understanding the taxonomy of these taxa.


1995 ◽  
Vol 46 (7) ◽  
pp. 1381 ◽  
Author(s):  
H Gomez-Macpherson ◽  
RA Richards

The main environmental constraints to the yield of dryland wheat in south-eastern Australia are: a low and erratic rainfall throughout the growing season, the chance of frost at flowering time, and high temperatures during the grain-filling period. The aims of this work were threefold. Firstly, to determine which sowing period minimizes these constraints and results in the highest yields. Secondly, what is the optimum flowering time for a given sowing date so that maximum yield is achieved. The third aim was to determine whether any crop characteristic was associated with high yield or may limit yield in the different sowings. The experiments were conducted at three sites in New South Wales that were representative of dry (Condobolin) and cooler and wetter (Moombooldool, Wagga Wagga) sites in the south-eastern wheatbelt. In this study several sets of isogenic material, involving a total of 23 genotypes, that were similar in all respects except for flowering time, were sown early (mid-April and early May), normal (mid to late May) and late (June to mid July). Characteristics of the highest-yielding lines in each experiment are presented. The average flowering time of the highest yielding lines in all sowings had a range of only 12 days at the driest site, but a range of over 20 days at the coolest and wettest site. The optimum anthesis date (day of year, y) was related to sowing date (day of year, doy) at the cooler sites such that: y = 245+0.32 doy (r2 = 0.86) and at Condobolin, y = 253+0.19 doy (r2 = 0.91). Optimum anthesis date expressed in thermal time (�C days) after sowing (y) was related to sowing time (doy) as follows: y = 2709 -8-3 doy (r2 = 0.84). It is suggested that these relationships are likely to be quite robust and should hold true for similar thermal environments in eastern Australia. There was little variation in grain yield between the earliest sowing in mid-April (108 doy) and sowings throughout May (up to 147 doy). Grain yield declined 1.3% per day that sowing was delayed after late May. Aboveground biomass was substantially higher in early sown crops. However, this did not translate into higher yields. From the evidence presented it is argued that the principal reason that greater yields were not obtained in the early sowings, particularly in the April sowing, was the greater competition for assimilates between the growing spike and the elongating stem. It is suggested that a way of overcoming this competition is to genetically shorten the stems of winter wheats. This should capitalize on the considerable advantages in terms of water use efficiency that early sowing offers and result in greater yields. Barley yellow dwarf virus, although present at the cooler, wettest site in one year, was more frequent in the later sowings than in the early sowing and was not likely to have contributed to the lower than expected yields in the early sowings.


1989 ◽  
Vol 29 (1) ◽  
pp. 43 ◽  
Author(s):  
WA Cowling ◽  
PM Wood

Resistance to Phomopsis stem and pod blight, caused by Phomopsis leptostromiformis (Knhn) Bubak, in narrow-leafed lupin (Lupinus angustifolius L.) was consistently expressed at 5 sites in the southwest of Western Australia and 5 sites in south-eastern Australia in 1984. There was a high correlation (r = 0.95, P< 0.001) of mean Phomopsis stem ratings on the 8 breeding lines and 2 cultivars between the 2 regions of southern Australia. The mean frequency of seed infection by P. leptostromiformis in 6 resistant lines in Western Australia ranged from 0.1 to 1.0% compared with 1.4% in 75A65-5 (a line with intermediate resistance) and 2.0% in Yandee and Chittick (susceptible cultivars). In south-eastern Australia, mean seed infection in 6 resistant lines ranged from 0.0-0.6% compared with 2.3% in 75A65-5, 1.6% in Yandee, and 1.1% in Chittick. There was also a correlation (r = 0.73, P < 0.05) of mean seed infection levels in the 8 lines and 2 cultivars between the regions. Pod blight occurred at significantly lower frequency in resistant lines than in susceptible cultivars at 3 sites in Western Australia where pod lesions were visible. Correlations among Phomopsis stem ratings, pod blight severity, and the frequency of seed infection among lines and cultivars were significantly positive in all comparisons at individual sites and when averaged across the 2 regions of southern Australia.


2009 ◽  
Vol 22 (4) ◽  
pp. 296 ◽  
Author(s):  
A. S. Harvey ◽  
Wm J. Woelkerling ◽  
A. J. K. Millar

The genus Lithophyllum (Lithophylloideae, Corallinaceae, Rhodophyta) is represented by six species in south-eastern Australia L. chamberlainianum Woelkerling & Campbell, L. corallinae (Crouan & Crouan) Heydrich, L. cuneatum Keats, L. pustulatum (Lamouroux) Foslie, L. riosmenae, sp. nov., and L. stictaeforme (Areschoug in Agardh) Hauck. Four of these taxa are commonly found in Australia, whereas L. cuneatum was previously known only from Fiji and L. riosmenae is newly described. Morphological and anatomical accounts are provided, including keys, information on distribution, nomenclature and habitat in south-eastern Australia. South-eastern Australian species are primarily delimited on characters relating to tetrasporangial conceptacles and the presence/absence of a semi-endophytic habit. Ten species of Lithophyllum are now confirmed to occur in Australia and their diagnostic characters are detailed. Confirmed Australian species of Lithophyllum are primarily delimited on characters relating to tetrasporangial conceptacles, the presence/absence of a semi-endophytic habit and the growth-form. Biogeographic comparisons between south-eastern Australia and other Australian biogeographic regions are also made. Eight species of Lithophyllum are known to occur in southern Australia, three in tropical eastern Australia and three in subtropical western Australia. Southern and south-eastern Australia show major overlap, with five species occurring in both regions. L. pustulatum and L. stictaeformae are widely distributed, having been confirmed to occur in eastern tropical, western subtropical, warm temperate and cold temperate waters within Australia.


1998 ◽  
Vol 49 (3) ◽  
pp. 419 ◽  
Author(s):  
J. Evans ◽  
D. P. Heenan

Procedures for assessing the quantity of symbiotically fixed nitrogen (kg N/ha) in standing crops of lupin and for estimating variation of N2 fixation by lupins in different years were determined empirically and described. In standing crops, N2 fixation was estimated from crop height, plant population density, and a bioassay of soil mineral nitrogen (cereal crop N; kg N/ha). In addition it was also estimated from rainfall, sowing date, and cereal N, which consequently enabled prediction of seasonal variation in fixed N using historical rainfall data. Procedures for estimating the potential contribution of N2 fixation to soil N, and the effects of lupin and cereal N budgets on soil N balance based on differences in fixed N and grain N (grain yield×estimated grain N concentration) are also given. The collective procedures are applied to a site in south-eastern Australia and the predicted crop effects on soil N balance compared with actual field data. Perceived limitations of the procedures are discussed.


1982 ◽  
Vol 33 (5) ◽  
pp. 917 ◽  
Author(s):  
BJ Richardson

Eight polymorphic loci were detected in a survey for electrophoretically detectable protein variation, carried out using liver samples from the Australian jack mackerel, T. declivis. The distribution of gene and genotype frequencies in sample sets from different areas shows that distinct subpopulations of the species occur in Western Australia and in New Zealand and that two or more geographically overlapping but genetically distinct subpopulations occur in the waters around south-eastern Australia.


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