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0000-0002-0423-2517
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University of New England
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Publisher: Elsevier BV
Date: 03-1996
Publisher: Wiley
Date: 03-1994
Publisher: CSIRO Publishing
Date: 1992
DOI: 10.1071/AR9920123
Abstract: Two crops of sorghum were grown in successive summer seasons at 3 sites on alkaline, black earth soils near Tamworth, New South Wales following either soyabeans, mungbeans, cowpeas, pigeonpeas, sunflowers or sorghum. Tillage practices were cultivation using a chisel plough and scarifier, and no-tillage using atrazine and glyphosate for weed control. Variation in grain yield (1.0-8.4 t/ha) was largely associated with variation in Dec.-Feb. rainfall (128-475 mm). An average of 15 kg grain/ha was produced for each mm water above the threshold value of 83 mm. At the high (Site A) and low (Site C) N-fertility sites, the rotation effect on sorghum yields was significant for one year, but did not carry over to a second sorghum crop. Cowpeas were the best rotation crop, followed by sunflowers mungbeans and soyabeans. At the low N-fertility site, sorghum following cowpeas outyielded sorghum after sorghum by 47% in the unfertilized plots and by an aExperiments to examine the effects of tillage practice and crop sequence on the production of sorghum grain in northern New South Wales are described. Two crops of sorghum were grown in successive seasons at three sites on alkaline, black earth soils near Tamworth following either soybean, mungbean, cowpea, pigeonpea, sunflower or sorghum. Tillage practices were cultivation using a chisel plough and scarifier, and no-tillage using atrazine and glyphosate for weed control. Variation in grain yield (1.0 to 8.4 t/ha) was largely associated with variation in December-February rainfall (128 to 475 mm). We calculated that an average of 15 kg/ha of grain was produced for each mm water above the threshold value of 83 rnm. At the high (Site A) and low (Site C) N-fertility sites, the rotation effect on sorghum yields was significant for one year, but did not carry over to a second sorghum crop. Cowpea was the best rotation crop, followed by sunflower, mungbean and soybean. At the low N-fertility site, sorghum following cowpea outyielded sorghum after sorghum by 47% in the unfertilized plots and by an average of 27% over all N treatments. It is likely that the increased yields of sorghum in the rotation plots resulted from higher levels of plant available N from both N2 fixation activity (legumes only) and reduced amounts of N removed with the harvested grain (particularly cowpea and sunflower). At the non-responsive, moderate-fertility Site B, water, rather than N, was limiting. Responses to no-tillage were apparent only in the very dry 1984/85 season (December to February rainfall, 42% below average). In the other three seasons, the cultivated crops outyielded the no-tilled crops or the differences between the two practices were not significant.
Publisher: Elsevier
Date: 1990
Publisher: Springer Science and Business Media LLC
Date: 06-1974
DOI: 10.1007/BF00010508
Publisher: CSIRO Publishing
Date: 1998
DOI: 10.1071/A97068
Abstract: Functions quantifying relationships between N2 fixation by legumes and other factors would be useful to farmers in the management of legumes and nitrogen in their production systems. The 2 most critical factors regulating N2 fixation are legume yield and soil nitrate and both should be included as independent variables in the functions. Data from 9 experiments in northern New South Wales on soil nitrate at sowing, yields of shoot and grain dry matter (DM) and N of chickpea, and δ15N of shoots of chickpea and non N2-fixing reference crops (wheat, barley, and uninoculated chickpea) were used to determine the percentage of chickpea N derived from N2 fixation (P fix), total N2 fixed, and N balance (fixed N2 minus grain N). Data were then subjected to simple and multivariate regression analyses with Pfix and total N2 fixed as the dependent variables and soil nitrate, shoot N, and grain yield as the independent variables. Simple regression coefficients (r2) for Pfix were 0·26 with shoot N as the independent variable, 0·59 with soil nitrate, and 0·62 with grain yield. Coefficient values were increased in the 2-factor (multiple) regressions to 0·74 (P ·001) for soil nitrate plus shoot N, and 0·82 (P 0·001) for soil nitrate plus grain yield. For total N2 fixed, the regression coefficient was lower at 0·68 (P 0·001), using soil nitrate plus grain yield. We tested the functions against an independent data set with best prediction of Pfix involving the nitrate and grain yield equation (r2 = 0·83 P 0·001). Total N2 fixed was not well predicted. We concluded that further development of such functions is warranted to refine both accuracy and precision for chickpea and to extend the approach to other species.
Publisher: Springer Science and Business Media LLC
Date: 1993
DOI: 10.1007/BF00027186
Publisher: CSIRO Publishing
Date: 1998
DOI: 10.1071/A97067
Abstract: Rotational effects of chickpea, an important N2-fixing pulse legume of the northern grains region, on subsequent wheat require quantification of the contribution of the legume to soil N and the N status of the wheat, and of suppression of soil and stubble-borne pathogens, such as crown rot (Fusarium graminearum Schwabe Group 1). Results from selected treatments of 10 experiments in northern New South Wales in which chickpea and wheat in one season were followed by wheat in following seasons indicated generally higher dry matter (DM) and grain yields of wheat after chickpea than after wheat. Responses to chickpea were -0·8 to 3·3 t/ha (shoot DM) and -3 to 39 kg N/ha (shoot N). Responses in wheat grain yields were -0·1 to 1·7 t/ha (mean 0·85 t/ha) grain N responses were -2 to 33 kg/ha (mean 19 kg/ha). Grain protein responses were small (0·6%) and variable. Although these productivity responses could be explained largely in terms of additional nitrate-N following chickpea, we measured reduced incidences of crown rot in wheat after chickpea (range 1-36%, mean of 12%), compared with wheat after wheat (range 5-52%, mean 30%). Modelling the incidence of crown rot indicated highly significant interactions between prior crop and total water (pre-plant soil water plus in-crop rainfall). When wheat followed chickpea, incidence of the disease declined sharply with increasing water. When wheat followed wheat, there was a marginal decline in disease incidence with increasing water. Our results support the strategy of using legumes in rotation with wheat in the northern grains region for enhanced soil-N supply and disease-break effects.
Publisher: Elsevier BV
Date: 04-2015
Publisher: Springer Science and Business Media LLC
Date: 04-2014
Publisher: CSIRO Publishing
Date: 2018
DOI: 10.1071/SR18108
Abstract: To contribute to national greenhouse gas emissions (GHG) reduction targets, grain growers need strategies that minimise emissions associated with grain production. We used life cycle assessments (LCAs) with field-measured production inputs, grain yields and proteins, legume nitrogen (N2) fixation, and soil nitrous oxide (N2O) and methane (CH4) emissions, to explore mitigation strategies in 3-year crop sequences in subtropical Australia. The sequences were: canola plus 80 kg/ha fertiliser nitrogen (80N)–wheat 85N–barley 65N (CaNWtNBaN), chickpea 0N–wheat 85N–barley 5N (CpWtNBa), chickpea 0N–wheat 5N–chickpea 5N (CpWtCp), and chickpea 0N–sorghum 45N (CpSgN). We also assessed the impacts of split fertiliser N application and urea coated with DMPP, a nitrification inhibitor, on the LCA for the CaNWtNBaN sequence. Total pre-farm plus on-farm GHG emissions varied between 915 CO2-e/ha (CpSgN) and 1890 CO2-e/ha (CaNWtNBaN). Cumulative N2O emitted over the 3-year study varied between 0.479 kg N2O-N/ha (CpWtCp) and 1.400 kg N2O-N/ha (CaNWtNBaN), which constituted 24–44% of total GHG emissions. Fertiliser production accounted for 20% (CpSgN) to 30% (CaNWtNBaN) of total emissions. An extra 4.7 kg CO2-e/ha was emitted for each additional kg N/ha of applied N fertiliser. Three-year CH4 emissions ranged from −1.04 to −0.98 kg CH4-C/ha. Split N and DMPP strategies could reduce total GHG emissions of CaNWtNBaN by 17 and 28% respectively. Results of the study indicate considerable scope for reducing the carbon footprint of subtropical, dryland grains cropping in Australia.
Publisher: Springer Science and Business Media LLC
Date: 06-10-2021
Publisher: Elsevier BV
Date: 1988
Publisher: CSIRO Publishing
Date: 1987
DOI: 10.1071/AR9870061
Abstract: Three closely related strains of Rhizobium japonicum, equally effective in N2 fixation, were used to inoculate each of three successive crops of soybeans [Glycine rnax (L.) Merr. cv. Bragg] grown on the same block of land. The soil was a vertisol previously free of R. japonicum, and inoculant was applied at different rates by spraying a suspension of peat culture into the seed bed at time of sowing the seed. The populations of rhizobia that developed in rhizosphere and soil were counted at intervals during crop growth and in the fallow period between crops. There was usually a substantial decline in recovery of inoculant strains immediately after sowing. In soil initially devoid of R. japonicum, populations in the rhizospheres of young seedlings were related to rates of inoculation, but differences disappeared as the plants aged. Shortly after harvest, the soil contained large populations of rhizobia which increased up to 200 times during the fallow period between crops, probably due to release of bacteria from disintegrating nodules. The size of these populations was maintained up to the time of sowing the following crop. Although strains used for second- and third-year crops were dominated by already established rhizobia in rhizosphere colonization and nodule formation, the magnitude of the domination could be reduced by increased rates of inoculation. In soil already containing R. japonicum, the proportion of nodules formed by inoculant strains was greater than the relative number of inoculant rhizobia in the soil or the rhizosphere this was ascribed to an advantage of specific placement of the inocula in that zone of the soil where infection foci first formed. The results are explicable in numerical terms and are discussed in relation to an inoculation strategy for maximum nodulation by applied inoculant in competition with rhizobia already established in soil.
Publisher: Oxford University Press (OUP)
Date: 1989
DOI: 10.1093/JXB/40.5.535
Publisher: Elsevier BV
Date: 04-1995
Publisher: Informa UK Limited
Date: 25-03-2002
Publisher: CSIRO Publishing
Date: 1991
DOI: 10.1071/EA9910679
Abstract: The relationships between the relative abundance of ureide-N in xylem sap and nodulation characteristics of navy beans (Phaseolus vulgaris) were examined in a sandy field site that enabled good nodule recovery. Three management treatments of N fertiliser, inoculation and no inoculation were used in the irrigated trial. Five cultivars were sown, and they were s led 48 and 83 days later. Plant roots were scored visually for nodule size, colour, abundance and mass. Xylem sap was extracted from shoots under mild vacuum and assayed for ureide, nitrate and amino-N contents. Main treatment effects on nodulation were detected in the first but not the second s ling. Cultivar differences were found in the second s ling only. The relative abundance of ureide-N in xylem sap, measured as 100 x 4 x ureides/(4 x ureides + nitrate + amino-N), was low ( %) in the first s ling, with no differences between cultivars. Fertiliser N depressed the ureide levels. At the second s ling, relative ureide-N ranged from 30 to 40% but there were no differences between management treatments or cultivars. Correlations between relative ureide-N and nodulation characteristics (abundance, size, colour, mass) were significant for each s ling (48 days, r = 0.29-0.33 83 days, r = 0.72-0.76). The results indicate that it is possible to use a ureide assay as an alternative to nodule scoring where nodule recovery is impracticable in field studies of P. vulgaris.
Publisher: CSIRO Publishing
Date: 1988
DOI: 10.1071/AR9881029
Abstract: The effect of the narrow-leafed lupin (Lupinus angustifolius L.) on growth and production of subsequent cereal crops was studied at three sites on the acidic, N-infertile soils of the Pilliga Scrub region of northern New South Wales.Beneficial effects of lupins on dry matter production were evident in either one (Kamala, Florida A) or two subsequent crops of wheat (Florida B). In the absence of fertilizer N, wheat following lupins outyielded wheat following wheat by an average of 57%. At Florida B, the second wheat crop following lupins outyielded the wheat only plots by 35%. The response to lupins was established early in vegetative growth and was essentially maintained. Effects of lupins on grain yields, evident at all sites in the first crop, were maintained at the two Florida sites for a second crop. Increases in the absence of fertilizer-N were between 0.29 and 1.22 t ha-1 (55 and 145%) (crop 1) and as great as 0.39 t ha-1 (38%) in year 2. Barley responded similarly with increases of 127 and 47% in years 1 and 2, respectively. Amounts of fertilizer required to raise the yields of wheat following wheat to those of wheat following lupins ranged between 40 and 80 kg ha-1. Effects of lupins on protein concentration of cereal grains were inconsistent largest effects were achieved through N fertilization. Both the incidence and severity of root diseases at Florida A were reduced in the rotation plots the effect persisted into the third wheat crop following lupins. Disease control was not a factor in the lupin effect at Kamala. Nitrogen budgets for the unfertilized wheat-wheat and lupinwheat sequences at Kamala and Florida A indicated that lupin cropping (i) resulted in potential net gains of soil N of 128 (Kamala) and 29 kg ha-1 (Florida A), and (ii) increased N yields of the following wheat crops by 37 (Kamala) and 20 kg ha-1 (Florida A).
Publisher: Springer Science and Business Media LLC
Date: 2001
Publisher: Springer Science and Business Media LLC
Date: 11-07-2008
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/AR00186
Abstract: The growth and yield of fababean (Vicia faba) in temperate environments has been well described however, information is lacking on the response of the crop to the higher temperature and radiation conditions of subtropical regions. Our aim in this study was to quantify fababean canopy development, radiation interception, radiation use efficiency, biomass partitioning, and nitrogen (N) accumulation and partitioning in a subtropical winter environment and to investigate if parameters describing these processes were consistent between temperate and subtropical regions. Two of the most important factors effecting growth patterns and yield in the field are crop density and water supply. Thus, 2 field experiments were conducted at Lawes, south-eastern Queensland, over 2 seasons, the first concentrating on the effect of plant density and the second on varying water deficit, both using the widely adapted cv. Fiord. Main-stem nodes appeared at the rate of one node every 54 degree-days (base temperature 0˚C), with no effect of plant density. With the addition of each main-stem node, plants produced a constant 5.22 leaves per node until the start of grain-filling, at which time assimilate became limiting. High plant density decreased both the number of leaves produced and the size of in idual leaves on later formed branches. Radiation use efficiency values of 1.03–1.29 g/MJ were determined for plants grown under well-watered conditions, with a lower value (0.83 g/MJ) for a partly irrigated crop. The measured radiation extinction coefficient was 0.73 for leaf area index values ranging from 0.4 to 7.5, pooled across experiments and treatments. Leaf and stem were partitioned in equal proportions until pod set, and the root : shoot ratio was c. 0.8 at the beginning of pod set. The rate of increase in harvest index (HI) during pod filling was 0.012/day, except under fully irrigated conditions in 1999, when HI was much reduced, possibly due to pod shedding. Parameters such as the extinction coefficient, partitioning between leaf and stem, and rate of main-stem node appearance appeared to be quite conservative in response to density and water deficit, and were within the range of published values from temperate and Mediterranean environments. This is an encouraging outcome and suggests that it should be possible to simulate growth and yield of fababean across the erse climate zones in which the crop is grown in Australia by using a single simulation model.
Publisher: CSIRO Publishing
Date: 1999
DOI: 10.1071/EA99108
Abstract: Summary. Levels of nitrogen fixation by navy and culinary beans (Phaseolus vulgaris L.) in Australia are low and contribute little to the N economies of the crops. As a consequence, they must be grown in highly fertile soils or fertilised with N to obtain economic yields. Eliminating the need for fertiliser nitrogen would save growers A$1 million annually. Following a 10-year program in which almost 1500 genotypes of P. vulgaris were screened for superior nodulation and nitrogen fixation, we conducted experiments at the Southedge Research Station, Mareeba, during 1995–97 to identify elite genotype(s), which could either be released as cultivar(s) or used as donor parent(s) in a breeding program. Selection criteria were plant biomass, nitrogen fixation activity assessed using the ureide method and grain yield. The best-performing genotypes were ICA20667 and ICA21573. They produced about 20% more shoot biomass than the commercial check cultivars, Spearfelt, Gallaroy and Rainbird, and had Pfix (percentage of plant nitrogen derived from nitrogen fixation) values that were consistently about 30% higher. However, both genotypes responded strongly to fertiliser nitrogen ( % increase in shoot nitrogen and % increase in grain yield at rate of 150 kg nitrogen/ha), suggesting that their nitrogen fixation capacity was inadequate. This study reinforced current recommendations that commercial crops of P. vulgaris be fertilised with nitrogen and indicated a low likelihood of release of high nitrogen-fixing cultivars to growers in the immediate future.
Publisher: CSIRO Publishing
Date: 1975
DOI: 10.1071/EA9750780
Abstract: S les of preinoculated legume seed were obtained from commercial outlets in southeastern Australia and compared with seed inoculated in the laboratory at currently recommended rates for the numbers of rhizobia associated with the seed and performance when grown in the field and in soil in a glasshouse. There were more than 100 times as many rhizobia on laboratory-inoculated seed as on preinoculated seed. There were no detectable rhizobia on three of the 48 s les of preinoculated seed examined, 22 other s les carried very low numbers, and all but one fell below standards derived from Australian lnoculant Research and Control Service requirements. When grown in soil containing naturally-occurring or added rhizobia, laboratory-inoculated seed was generally superior to preinoculated seed in percentage recovery of inoculant strains from nodules. The differences became greater as the size of soil populations of rhizobia increased. Where naturally-occurring rhizobia were few in number or absent nodulation was satisfactory provided that the seed carried viable rhizobia at time of sowing. The numbers of rhizobia associated with laboratory preparations of inoculated seed represented the potential standards that should be the commercial objective. The consistently lower numbers on preinoculated seed indicated that some stage (or stages) of the preinoculation process itself has a letha effect on the inoculant.
Publisher: CSIRO Publishing
Date: 1975
DOI: 10.1071/EA9750264
Abstract: The nodulation and growth of Lablab purpureus was studied at three sites on the far north coast of New South Wales. These sites were chosen to provide low, medium and high competition by naturalised rhizobia for the seed-borne inocula. The effect of seedbed preparation was studied at the low competition site. Maximum yield occurred with clean cultivation although response to inoculation was best in a rough seedbed or when sod sown. Additional lime improved legume growth when it was dependent on symbiotic nitrogen but had no effect with a clean seedbed. Effective strains CB1091 and CB1406 established poorly at the high and low competition sites respectively. Strain CB1024 established well at all sites and with the three different methods of seedbed preparation.
Publisher: Springer Science and Business Media LLC
Date: 05-1988
DOI: 10.1007/BF02370109
Publisher: Springer Science and Business Media LLC
Date: 17-10-2014
Publisher: Elsevier BV
Date: 02-2019
Publisher: Springer Science and Business Media LLC
Date: 05-1988
DOI: 10.1007/BF02370107
Publisher: Elsevier BV
Date: 03-2019
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/CP13397
Abstract: Chickpea (Cicer arietinum L.) is considered an effective rotation crop in Australia’s northern grains region however, concerns exist that grain yields of commercial crops are reduced because of nitrogen (N) deficiency related to inadequate nodulation and N2 fixation. As part of a program to address these issues, we report on the monitoring of 22 commercial fields around Moree, northern NSW, during 2005–07 that were designated for chickpea, and an associated farmer survey (81 respondents). Our objectives were to determine whether the monitored crops were limited by N and to develop recommendations that would optimise productivity for farmers growing chickpeas. In 2005, only soil water and nitrate data were collected from the six fields designated for chickpea. In 2006 and 2007, almost complete datasets were assembled from the 16 chickpea fields or crops, including soil water and nitrate at sowing, row spacing, plant density, plant height, stubble cover, weed density and composition, shoot biomass, grain yield, nodulation and N2 fixation (%N derived from the atmosphere (%Ndfa) and total crop N fixed). The associated survey provided insights into farmer knowledge of, and practices related to, inoculation. Field monitoring indicated moderate–high levels of soil nitrate at sowing (averages 114, 126 and 110 kg N ha–1 to 1.2 m depth for 2005, 2006 and 2007, respectively) and generally low plant nodulation (0.11–1.16 g fresh wt plant–1) and N2 fixation (0–62%Ndfa and 0–87 kg N ha–1). Grain yield varied between 0.53 and 2.91 t ha–1 across the 14 monitored crops, with averages of 1.89 t ha–1 in 2006 and 1.02 t ha–1 in 2007. Although total crop N and grain yields were highly correlated with total (i.e. soil + fixed) N supply, there was no evidence that the monitored chickpea crops were N-limited. Rather, we conclude that soil N and biologically fixed N were complementary in supplying N to the crops, the grain yields of which were primarily determined by the supply of plant-available water (PAW) and water-use efficiency (WUE). Simple and multivariate regression analyses showed that stubble cover during the fallow (positively correlated with sowing PAW) and sowing date (positively correlated with crop WUE) were significant determinants of grain yield. We conclude that farmers could improve inoculation practice by ensuring the time between seed inoculation and sowing is always h.
Publisher: CSIRO Publishing
Date: 1988
DOI: 10.1071/AR9880965
Abstract: Four commercial procedures for inoculating soybean (Glycine max [L.] Merr.) with Bradyrhizobium japonicum were compared at three sites in New South Wales. Three procedures involved applying inoculant to the seed shortly before sowing (seed inoculation) as a slurry in water or gum arabic adhesive or by sprinkling inoculant on the seed in the seed box of the planter. In the fourth, inoculant was suspended in water and sprayed directly into the seed bed alongside and beneath the seed (liquid inoculation).With seed inoculation substantial losses of viability of inocula (94%-99.95%) occurred between inoculation and sowing. Some of the loss was attributable to separation of inoculant and seed, as it passed through the machinery no such loss of viability occurred with liquid inoculation. Colonization of the rhizosphere relative to the numbers of rhizobia delivered into the seed bed was poorer with liquid inoculation than with the slurry treatments. This was attributed to the uniform distribution of rhizobia applied as liquid inoculant in the seed bed, in contrast to the concentration of rhizobia applied as slurries in the vicinity of each seed. Slurry treatments generally promoted earlier nodulation than liquid inoculation, but as the crops aged, the differences disappeared and were not reflected in seed yield or seed nitrogen. Application of inoculant to seed in the seed box, although better than an uninoculated control, was consistently inferior to the other inoculation procedures.Given favourable environmental conditions both at sowing and afterwards, slurry inoculation and liquid inoculation were equally likely to initiate a successful symbiosis. Slurry inoculation may be superior when there is limited soil moisture after sowing, whereas liquid inoculation may be better when seed is sown into relatively dry soil with good moisture beneath.
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/SR16336
Abstract: Effective management of fertiliser nitrogen (N) inputs by farmers will generally have beneficial productivity, economic and environmental consequences. The reality is that farmers may be unsure of plant-available N levels in cropping soils at sowing and make decisions about how much fertiliser N to apply with limited information about existing soil N supply. NBudget is a Microsoft (Armonk, NY, USA) Excel-based decision support tool developed primarily to assist farmers and/or advisors in Australia’s northern grains region manage N. NBudget estimates plant-available (nitrate) N at sowing it also estimates sowing soil water, grain yields, fertiliser N requirements for cereals and oilseed crops and N2 fixation by legumes. NBudget does not rely on soil testing for nitrate-N, organic carbon or soil water content. Rather, the tool relies on precrop (fallow) rainfall data plus basic descriptions of soil texture and fertility, tillage practice and information about paddock use in the previous 2 years. Use is made of rule-of-thumb values and stand-alone or linked algorithms describing, among other things, rates of mineralisation of background soil organic N and fresh residue N. Winter and summer versions of NBudget cover the 10 major crops of the region: bread wheat, durum, barley, canola, chickpea and faba bean in the winter crop version sorghum, sunflower, soybean and mung bean in the summer crop version. Validating the winter crop version of NBudget estimates of sowing soil nitrate-N against three independent datasets (n=65) indicated generally close agreement between measured and predicted values (y=0.91x+16.8 r2=0.78). A limitation of the tool is that it does not account for losses of N from waterlogged or flooded soils. Although NBudget also predicts grain yields and fertiliser N requirements for the coming season, potential users may simply factor predicted soil N supply into their fertiliser decisions, rather than rely on the output of the tool. Decisions about fertiliser N inputs are often complex and are based on several criteria, including attitudes to risk, history of fertiliser use and costs. The usefulness and likely longevity of NBudget would be enhanced by transforming the current Excel-based tool, currently available on request from the author, to a stand-alone app or web-based tool.
Publisher: Springer Science and Business Media LLC
Date: 16-10-2015
Publisher: Oxford University Press (OUP)
Date: 06-1990
DOI: 10.1104/PP.93.2.495
Publisher: Oxford University Press (OUP)
Date: 1988
DOI: 10.1093/JXB/39.1.12
Publisher: CSIRO Publishing
Date: 1987
DOI: 10.1071/AR9881017
Abstract: Experiments were commenced in 1978 to evaluate the impact of the narrow-leafed lupin (Lupinus angustifolius L.) on production of subsequent wheat crops in the N-infertile, acidic soils of the Pilliga Scrub region of northern New South Wales. There were four sites. Production of lupin dry matter (shoots, roots) ranged from 5.0 (Florida A) to 11.4 t ha-1 (Kamala), reflecting seasonal rainfall and crop management. Lupin seed yields varied between 1.29 (Florida A) and 2.03 t ha-1 (Kamala) at two of the sites, yields were greater than the yields achieved by the adjacent wheat crops. At Spring Creek, the wheat was not harvested for grain due to the extremely poor plant growth. Seasonal profiles of C2H2 reduction by each of the four lupin crops reflected growth characteristics maximum activity coincided with rapid accumulation of dry mater. Diurnal profiles of C2H2 reduction were unaffected by plant age. Rates peaked around noon after rapidly increasing from minimum pre-dawn levels. Total N2 fixed by each of the lupin crops was estimated by comparing N Yields of the lupin and wheat crops. The various methods used resulted in almost identical estimates of N2 fixation at Kamala (215-218 kg ha-') and Spring Creek (222-228 kg ha-'). Estimates . of N2 fixed by the two Florida crops ranged from 72 to 101 (Florida A) and from 82 to 134 kg ha-' (Florida B). The data indicate that large amounts of N can be fixed by field-grown lupins, amounts well in excess of the quantities of N harvested in the seed.
Publisher: Wiley
Date: 02-1975
Publisher: Elsevier BV
Date: 06-2003
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/SR16330
Abstract: Nitrogen (N) contributed by legumes is an important component of N supply to subsequent cereal crops, yet few Australian grain-growers routinely monitor soil mineral N before applying N fertiliser. Soil and crop N data from 16 dryland experiments conducted in eastern Australia from 1989–2016 were examined to explore the possibility of developing simple predictive relationships to assist farmer decision-making. In each experiment, legume crops were harvested for grain or brown-manured (BM, terminated before maturity with herbicide), and wheat, barley or canola were grown. Soil mineral N measured immediately before sowing wheat in the following year was significantly higher (P 0.05) after 31 of the 33 legume pre-cropping treatments than adjacent non-legume controls. The average improvements in soil mineral N were greater for legume BM (60 ± 16 kg N/ha n = 5) than grain crops (35 ± 20 kg N/ha n = 26), but soil N benefits were similar when expressed on the basis of summer fallow rainfall (0.15 ± 0.09 kg N/ha per mm), residual legume shoot dry matter (9 ± 5 kg N/ha per t/ha), or total legume residue N (28 ± 11%). Legume grain crops increased soil mineral N by 18 ± 9 kg N/ha per t/ha grain harvested. Apparent recovery of legume residue N by wheat averaged 30 ± 10% for 20 legume treatments in a subset of eight experiments. Apparent recovery of fertiliser N in the absence of legumes in two of these experiments was 64 ± 16% of the 51–75 kg fertiliser-N/ha supplied. The 25 year dataset provided new insights into the expected availability of soil mineral N after legumes and the relative value of legume N to a following wheat crop, which can guide farmer decisions regarding N fertiliser use.
Publisher: Elsevier BV
Date: 03-1993
Publisher: Elsevier BV
Date: 05-2001
Publisher: CSIRO Publishing
Date: 1998
DOI: 10.1071/EA97078
Abstract: Summary. Nitrogen (N2 ) fixation accords pulse crops the potential to sustain or enhance total soil nitrogen (N) fertility. However, regional field experiments have shown that this potential is often not realised because N2 fixation is inhibited by the supply of nitrate N in the root zone (0–90 cm) coupled with a low demand for N during plant growth. The objectives of this study were to establish whether commercially grown chickpea and faba bean crops in the northern grain belt of New South Wales were depleting, maintaining or enhancing soil N fertility, and whether current farm management practices were maximising the N2 fixation potential of the crops. Fifty-one rainfed crops of chickpea (Cicer arietinum L.) and faba bean (Vicia faba L.) were surveyed in the Moree, Walgett and Gunnedah districts of north-west New South Wales during the winters of 1994 and 1995. Nitrogen fixation was measured using the natural 15N abundance technique. Net N balance was calculated for each crop by subtracting grain N harvested from fixed N2. Soil, plant and fallow conditions with potential to influence N2 fixation were also documented. The percentage of crop N derived from N2 fixation (Pfix) ranged from 0 to 81% for chickpea and 19 to 79% for faba bean. Nitrogen fixation of chickpea was uniformly low in the 1994 drought. Total N2 fixed ranged from 0 to 99 kg/ha for chickpea and 15 to 171 kg/ha for faba bean. Net N balance ranged from –47 to +46 kg N/ha for chickpea crops, and –12 to +94 kg N/ha for faba bean crops. About 60% of the difference in Pfix between chickpea and faba bean at the average level of soil nitrate (65 kg/ha) was explained by the higher N demand of the latter. The remaining 40% could be due to greater tolerance of the faba bean symbiosis to nitrate effects. In addition, faba bean had a lower N harvest index than chickpea, which meant that proportionally less N needed to be fixed by faba bean to offset removal of grain N. On average, Pfix needed to exceed 35% for chickpea and 19% for faba bean to balance soil N. The equivalent soil nitrate levels were 43 kg nitrate N/ha for chickpea and 280 kg/ha for faba bean (extrapolated from the relationship between measured Pfix and soil nitrate). Double-cropping chickpea into summer cereal or grass pasture stubble provided the most consistent strategy for achieving the low levels of soil nitrate.
Publisher: CSIRO Publishing
Date: 1984
DOI: 10.1071/AR9840149
Abstract: The symbiosis of the root-nodules of Bragg soybean [Glycine max (L.) Merrill] and the relative dependence of the plants on symbiotic and soil sources of N were evaluated in an experiment conducted on a vertisol which was high in organic- and mineral-N, free of Rhizobium japonicum, and where poor nodulation was characteristic of inoculated, new sowings. Effective inoculant containing R. japonicum strain CB 1809 was sprayed into the seed bed at three rates of application (10-fold intervals). Increasing rates of inoculant led to greater numbers of rhizobia in the rhizosphere and in the soil, and to improved nodulation. Uninoculated plants did not nodulate. High soil NO-3 (30 �g N/g, top 30 cm) did not prevent prompt, abundant colonization of rhizospheres by the bacteria from the inoculant, but nodule initiation was delayed and nodule development was retarded until 42 days after sowing. There was an acceleration in nodule formation and development between 42 and 62 days which coincided with a depletion of NO-3 from the top 60 cm of the soil profile. Nodulated and unnodulated soybeans took up NO-3 at similar times and rates to a soil depth of 90 cm only unnodulated plants utilized soil NO-3 below 90 cm. Vacuum-extracted stem (xylem) exudate was s led from plants throughout growth and analysed for nitrogenous solutes. The proportion of ureide-N relative to total-solutes-N in xylem sap was used as an index of symbiotic N2-fixation. The initial increase in concentrations of ureides coincided with the period of accelerated nodule formation and development between 42 and 62 days. Thereafter, there was a progressive increase in ureide concentrations in nodulated plants, and the levels were related to rate of inoculation, extent of nodulation, and to the decline in concentrations of soil NO-3. Ureide concentrations in unnodulated plants remained low throughout. The quantities of NO-3-N and �-NH2- N in xylem sap were not related to nodulation. The differences between treatments in terms of whole-plant N and grain N were less than predicted from the symbiotic parameters. This indicated that soybeans compensated for symbiotic deficiencies by more efficient exploitation of soil N and/or by more efficient redistribution of vegetative N into grain N, and that nodulation and soil NO-3 were interactive and complementary in meeting the N requirements of the crop.
Publisher: EDP Sciences
Date: 11-2002
DOI: 10.1051/AGRO:2002056
Publisher: Springer Science and Business Media LLC
Date: 04-1974
DOI: 10.1007/BF00011530
Publisher: CSIRO Publishing
Date: 2001
DOI: 10.1071/EA00041
Abstract: The nitrogen fixed by legumes is a valuable resource in agriculture, with crop legumes alone contributing as much as 20% of the nitrogen requirements of the world’s grain and oilseed crops. Increasing legume nitrogen fixation through genetic improvement and more efficient management would have large economic benefits. Breeding for improved nitrogen fixation has, to a large extent, not been successful. Suggested reasons include the difficulty in combining single traits like nitrogen fixation with other traits, such as disease resistance, seed quality and yield, a lack of focus of programs and a lack of screening methodologies. Agronomic management of legume nitrogen fixation offers other opportunities. The challenge is to package those opportunities and provide legume growers with tools for understanding the factors determining nitrogen fixation, while at the same time providing them with site-specific management options. The potential of simulation modelling for assessing genetic and management options for enhancing nitrogen fixation of soybean grown at Warwick in south-eastern Queensland was investigated in a series of 30-year simulations using the APSIM modelling framework. The APSIM–soybean module was first adjusted to reflect observed responses of nitrogen fixation to soil nitrate. The subsequent simulations indicated that (genetically based) symbiotic nitrate tolerance would have only marginal benefits on residual soil nitrate (7 kg N/ha at sowing soil nitrate of 100 kg N/ha). Management of the crop for highest grain yield through optimising sowing dates, plant density and fallow length provided the best opportunities for increasing nitrogen fixation. The use of APSIM as a tool for managing legume nitrogen fixation appears to have merit.
Publisher: Springer Science and Business Media LLC
Date: 2002
Publisher: Springer Science and Business Media LLC
Date: 07-1995
DOI: 10.1007/BF00032239
Publisher: Wiley
Date: 09-2017
Publisher: Springer Science and Business Media LLC
Date: 25-03-2022
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/SR15338
Abstract: The northern Australian grains industry relies on nitrogen (N) fertiliser to optimise yield and protein, but N fertiliser can increase soil fluxes of nitrous oxide (N2O) and methane (CH4). We measured soil N2O and CH4 fluxes associated with wheat (Triticum aestivum) and barley (Hordeum vulgare) using automated (Expts 1, 3) and manual chambers (Expts 2, 4, 5). Experiments were conducted on subtropical Vertosol soils fertilised with N rates of 0–160kgNha–1. In Expt 1 (2010), intense rainfall for a month before and after sowing elevated N2O emissions from N-fertilised (80kgNha–1) wheat, with 417gN2O-Nha–1 emitted compared with 80g N2O-Nha–1 for non-fertilised wheat. Once crop N uptake reduced soil mineral N, there was no further treatment difference in N2O. Expt 2 (2010) showed similar results, however, the reduced s ling frequency using manual chambers gave a lower cumulative N2O. By contrast, very low rainfall before and for several months after sowing Expt 3 (2011) resulted in no difference in N2O emissions between N-fertilised and non-fertilised barley. N2O emission factors were 0.42, 0.20 and –0.02 for Expts 1, 2 and 3, respectively. In Expts 4 and 5 (2011), N2O emissions increased with increasing rate of N fertiliser. Emissions were reduced by 45% when the N fertiliser was applied in a 50:50 split between sowing and mid-tillering, or by 70% when urea was applied with the nitrification inhibitor 3,4-dimethylpyrazole-phosphate. Methane fluxes were typically small and mostly negative in all experiments, especially in dry soils. Cumulative CH4 uptake ranged from 242 to 435g CH4-Cha–1year–1, with no effect of N fertiliser treatment. Considered in terms of CO2 equivalents, soil CH4 uptake offset 8–56% of soil N2O emissions, with larger offsets occurring in non-N-fertilised soils. The first few months from N fertiliser application to the period of rapid crop N uptake pose the main risk for N2O losses from rainfed cereal cropping on subtropical Vertosols, but the realisation of this risk is dependent on rainfall. Strategies that reduce the soil mineral N pool during this time can reduce the risk of N2O loss.
Publisher: Springer Science and Business Media LLC
Date: 06-2003
Publisher: CSIRO Publishing
Date: 1991
DOI: 10.1071/EA9910653
Abstract: Following numerous reports of nodulation failures in pigeonpea [Cajanus cajan (L.) Millsp.] crops in New South Wales, a series of experiments was conducted in glasshouses and at 6 locations in the field. When inoculated seed was grown in moist vermiculite or in sand beds in the glasshouse, pigeonpea nodulated, and fixed N2, normally but at 3 sites in the field, we could detect neither nodulation nor N2 fixation, despite adequate inoculation or a population of suitable rhizobia in the soil. At another site there was only sporadic occurrence of effective nodules. Nitrogen was fixed at 2 of the 3 field sites on acid soils, but at 1 site it appeared that nodulation was due to a naturally occurring population of soil rhizobia and not to the inoculant. When comparisons were made, pigeonpea was invariably inferior to symbiotically related legumes, cowpea and adzuki bean, in nodulation and N2 fixation. This inferiority was associated with substantially poorer rhizobial colonisation of pigeonpea rhizospheres. The experimental findings confirmed the anecdotal evidence that pigeonpea is an erratically nodulating grain legume on neutral and alkaline soils.
Publisher: CSIRO Publishing
Date: 1988
DOI: 10.1071/AR9881003
Abstract: Experiments to develop indices of N2 fixation activity for the narrow-leafed lupin (Lupinus angustifolius L.) are reported. In Experiment 1 Unicrop narrow-leafed lupins were inoculated at sowing with effective Rhizobium lupini WU425. The conversion factor relating C2H2 reduction to N2 fixation was not constant throughout growth but increased from 0.9 (50-60 day period) to 6.6 (110-120 days). A nodulation index [(nodule wt/shoot wt) x 100], developed to account for plant size, declined with increasing nitrate supply and with increasing plant age. However, minor shifts in the nodulation index represented large shifts in plant dependence on N2 fixation (p), when plants were 60-100% dependent on N2 fixation. Concentrations of nitrate in extracts of the shoot axes and nodulated roots increased with increasing nitrate supply. Although the presence of nitrate in the rooting medium was evidenced by its presence in xylem exudate, the relationship between nitrate supply and the nitrate contents of xylem exudate was generally poor. Functions were developed to describe the relationships between the nodulation index and p, and between both shoot and root nitrate and p. Other experiments highlighted the synchrony of nitrate supply and its appearance in root tissues and the lack of diurnal fluctuations in nitrate concentrations of plant parts.
Publisher: Elsevier BV
Date: 08-2004
Publisher: Springer Science and Business Media LLC
Date: 07-1995
DOI: 10.1007/BF00032242
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/CP15260
Abstract: We used life cycle assessment methodology to determine the cradle-to-farmgate GHG emissions for rainfed wheat grown in monoculture or in sequence with the break crops canola (Brassica napus) and field peas (Pisum sativum), and for the break crops, in the south-eastern grains region of Australia. Total GHG emissions were 225 kg carbon dioxide equivalents (CO2-e)/t grain for a 3 t/ha wheat crop following wheat, compared with 199 and 172 kg CO2-e/t for wheat following canola and field peas, respectively. On an area basis, calculated emissions were 676, 677 and 586 kg CO2-e/ha for wheat following wheat, canola and field peas, respectively. Highest emissions were associated with the production and transport of fertilisers (23–28% of total GHG emissions) and their use in the field (16–23% of total GHG emissions). Production, transport and use of lime accounted for an additional 19–21% of total GHG emissions. The lower emissions for wheat after break crops were associated with higher yields, improved use of fertiliser nitrogen (N) and reduced fertiliser N inputs in the case of wheat after field peas. Emissions of GHG for the production and harvesting of canola were calculated at 841 kg CO2-e/ha, equivalent to 420 kg CO2-e/t grain. Those of field peas were 530 kg CO2-e/ha, equivalent to 294 kg CO2-e/t grain. When the gross margin returns for the crops were considered together with their GHG emissions, the field pea–wheat sequence had the highest value per unit emissions, at AU$787/t CO2-e, followed by wheat–wheat ($703/t CO2-e) and canola–wheat ($696/t CO2-e). Uncertainties associated with emissions factor values for fertiliser N, legume-fixed N and mineralised soil organic matter N are discussed, together with the potentially high C cost of legume N2 fixation and the impact of relatively small changes in soil C during grain cropping either to offset all or most pre- and on-farm GHG emissions or to add to them.
Publisher: Springer Science and Business Media LLC
Date: 07-1995
DOI: 10.1007/BF00032241
Publisher: CRC Press
Date: 11-01-2016
Publisher: Springer Science and Business Media LLC
Date: 12-1992
DOI: 10.1007/BF00029075
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/AR01136
Abstract: Soil in which nodulated legumes are growing often contains more nitrate nitrogen (N) than soil in which unnodulated legumes or non-legumes are growing. There is conjecture, however, as to whether the extra or ‘spared’ N is due to reduced use of soil N by the legume or to net mineralisation of legume root and nodular N. We report results of a field experiment to quantify and compare, at different levels of soil-N supply, N2 fixation, and soil-N use by chickpea (Cicer arietinum) and fababean (Vicia faba). Wheat (Triticum aestivum) was included as a non-N2-fixing control. Plants of the 3 species were grown on a low-nitrate Vertosol with fertiliser N rates of 0, 50, and 100 kg/ha (0N, 50N, and 100N), applied 6 weeks before sowing. S les were collected at sowing and at 64, 100, 135, and 162 days after sowing (DAS) for analysis of soil nitrate, root, and grain dry matter (DM) and N and shoot DM, N, and 15N. The latter was used to estimate the percentage (%Ndfa) and total N fixed by the 2 legumes. Soil nitrate levels to a depth of 1.8 m at sowing were 11–17 kg N/ha (0N), 41–55 kg N/ha (50N), and 71–86 kg N/ha (100N). Grain yields of the 2 legumes were unaffected by soil-N supply (fertiliser N treatment), being 2.0–2.4 t/ha for chickpea and 3.7–4.6 t/ha for fababean. Wheat grain yields varied from 1.6 t/ha (0N) to 4.8 t/ha (100N). Fababean fixed more N than chickpea. Values (total plant including roots) were 209–275 kg/ha for fababean and 146–214 kg/ha for chickpea. Corresponding %Ndfa values were 69–88% (fababean) and 64–85% (chickpea). Early in crop growth, when soil N supply was high in the 100N treatment, fababean maintained a higher dependence on N2 fixation than chickpea (Ndfa of 45% v. 12%), fixed greater amounts of N (57 v. 16 kg/ha), and used substantially less soil N (69 v. 118 kg/ha). In this situation, soil N sparing was observed, with soil nitrate levels significantly higher in the fababean plots (P 0.05) than under chickpea or wheat. At the end of growth season, however, there were no crop effects on soil nitrate levels. Soil N balances, which combined crop N fixed as inputs and grain N as outputs, were positive for the legumes, with ranges 80–135 kg N/ha for chickpea and 79–157 kg N/ha for fababean, and negative for wheat (–20 to –66 kg N/ha). We concluded that under the starting soil nitrate levels in this experiment, levels typical of many cropping soils in the region, high-biomass fababean and chickpea crops will not spare significant amounts of soil N. In situations of higher soil nitrate and/or smaller biomass crops with less N demand, nitrate sparing may occur, particularly with fababean.
Publisher: Oxford University Press (OUP)
Date: 06-1990
DOI: 10.1104/PP.93.2.708
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/AR02105
Abstract: The objectives of this study were to quantify below-ground nitrogen (BGN) of rainfed fababean (Vicia faba), chickpea (Cicer arietinum), and barley (Hordeum vulgare) and to use the values to determine N balances for the 3 crops. The BGN fraction of legumes in particular represents a potentially important pool of N that has often been grossly underestimated or ignored in calculating such balances. A field experiment was conducted at Breeza on the Liverpool Plains, New South Wales, in which BGN of fababean, chickpea, and barley was estimated using 15N methodologies. Plants were grown in 0.32-m2 microplots and labelled with 15N on 5 occasions during vegetative growth with a total of 1.0 mL of 0.5% 15N urea (98 atom% 15N) using leaf-flap (fababean), leaf-tip (barley), or cut petiole (chickpea) shoot-labelling procedures. At peak biomass (146–170 days after sowing), all plant material and soil to 45 cm depth was s led from one microplot in each replicate plot and analysed for dry matter (DM), %N, and 15N. At plant maturity, the remaining 3 microplots in each replicate plot were harvested for shoot and grain DM and N. With fababean, 15N enrichments of intact roots and shoots were reasonably uniform at 537‰ and 674‰, respectively. Microplot soil at 0–25 cm depth had a 15N enrichment of 18‰ (natural abundance of 6.1‰). The 25–45 cm soil enrichment was 8.7‰ (natural abundance of 6.3‰). In contrast, 15N enrichment of chickpea shoots was about twice that of recovered roots (685‰ v. 331‰), and the soil enrichment was relatively high (30‰ and 8.8‰ for the 0–25 and 25–45 cm depths, respectively). The 15N enrichments of barley shoots and recovered roots were 2272‰ and 1632‰, respectively, with soil enrichments of 34‰ and 10.7‰ for the 0–25 and 25–45 cm depths, respectively. Estimates of BGN as a percentage of total plant N, after adjusting the 15N shoot-labelling values of fababean and chickpea for uneven distribution of 15N-depleted nodules, were 24% for fababean, 68% for chickpea, and 36% for barley. The BGN values were combined with N2 fixation (fababean and chickpea only) and shoot and grain yield data (all 3 species) to construct N budgets. The inclusion of BGN in the budgets increased N balances by 38 kg N/ha to +36 kg N/ha for fababean and by 93 kg N/ha to +94 kg N/ha for chickpea. As there was no external (N2 fixation) input of N to barley, the inclusion of BGN made no difference to the N balance of the crop of –74 kg N/ha. Such values confirm the importance of BGN of N2-fixing legumes in the N economies of cropping systems.
Publisher: Springer Science and Business Media LLC
Date: 14-07-2020
Publisher: CSIRO Publishing
Date: 1993
DOI: 10.1071/AR9930137
Abstract: Pigeonpea grown on the alkaline black earths (vertisols) of northern New South Wales often fails to fix detectable amounts of nitrogen (N), resulting in N deficient crops and depressed seed yields. We aimed to solve this problem through selection of plant genotypes that were adapted to these soil types. Selection criteria included the agronomic characteristics of maturity (days to flowering), determinacy and seed size, and symbiotic characteristics of nodulation and N2 fixation. In addition, the interactive effects of fertilizer Fe and N, plant genotype and strain of rhizobia on those characteristics were examined. The experiments reported were sown between November 1988 and December 1990 on alkaline vertisols (pH range 7.9-8.2) at Tamworth, Currabubula and Breeza, N.S.W. In Experiment 1, 108 genotypes were inoculated with Bradyrhizobium strain CB756 and sown at two sites. Nitrogen fixation could not be detected for 86 of the 100 genotypes sown at the Tamworth Agricultural Research Centre and for 51 of the 62 genotypes sown at Currabubula. Six of the genotypes had Pfix (proportion of plant N derived from N2 fixation) values of 10-19% compared with values of zero for five of the six combinations of three check cultivars (Quest, Quantum and C ea)x2 sites. A further five genotypes produced seed yields up to 0.20 t/ha (14%) higher than the average of the three check cultivars. Effects of fertilizer Fe (applied at sowing as FeEDDHA at rates of 0, 0.25, 1.0, 4.0 and 16.0 kg Fe/ha) and N (as nitrarn at 0 and 200 kg N/ha) and strain of Bradyrhizobium sp. (CB756 and CB1024) on symbiotic and yield parameters of pigeonpea cv. Quest were examined in Experiment 2. Nodulation at flowering was increased by as much as 300% by Fe by early pod-fill, effects of Fe has almost disappeared. Piix values were unaffected by Fe. Throughout growth, shoot dry matters increased with increasing rates of Fe, particularly when N was also applied. In the presence of fertilizer N, seed yields increased with increasing rates of Fe (1.67 t/ha at Fe0 to 2.43 t/ha at Fe16.0). Responses to Fe in the absence of N were reduced. Plants inoculated with rhizobial strain CB1024 outyielded plants inoculated with strain CB756 by 1.0 t/ha (Fe0) and 0.66 t/ha (Fe16.0). In Experiment 3, we examined the effects of fertilizer Fe on symbiotic and yield parameters of 14 genotypes of pigeonpea. There were significant differences between plant genotypes in nodulation, N2 fixation and yields of shoots and seed when fertilizer Fe was not applied and in responsiveness to applied Fe. Seed yields were increased by an average of 0.70 t/ha (108%) for highly responsive genotypes E33, M96, L133 and C ea, but only by an average of 0.32 t/ha (25%) for the low response group (E76, M48, MI44 and Quest).
Publisher: Informa UK Limited
Date: 08-1991
Publisher: Springer Science and Business Media LLC
Date: 12-03-2015
Publisher: Elsevier BV
Date: 03-2000
Publisher: CSIRO Publishing
Date: 1989
DOI: 10.1071/EA9890671
Abstract: An experiment to examine the effect of tillage practice on yield, nodulation and nitrogen fixation of soybean in a podsolic soil on the far north coast of New South Wales is reported. Soybeans were sown into either a cultivated or no-tilled seedbed following pasture in 1983 and 1984, and following soybeans in 1984 and 1985. Results over the 3 seasons indicated substantially improved nodulation under no-tillage. The mean nodulation index (nodule mass as a percentage of shoot mass) was 4.5 for no-tillage soybean and 2.3 for the cultivated crops. Nitrogen fixation, assessed using the ureide technique, was higher in the no-tillage plots, especially during early plant growth, Plant growth and seed yield were increased by no-tillage in the wetter 1984 season the reverse occurred in the other 2 less favourable years. Data on crop N, seed N, and fixed N (estimated by partitioning N accumulated by the crops during successive periods of growth, according to the relative ureide values) were combined to calculate N balances. Potential gains of soil N were greatest under the no-tilled soybeans (as much as 110 kg Nha mean over all seasons was 80 kg Nha). The cultivated crops showed a maximum gain of 86 kg N/ha and an average gain of 30 kg N/ha. The data indicate that soybean has the potential to improve the N fertility of podsolic coastal soils, particularly when grown using no-tillage practices.
Publisher: Wiley
Date: 02-1975
Publisher: Oxford University Press (OUP)
Date: 1978
DOI: 10.1093/JXB/29.2.401
Publisher: Springer Science and Business Media LLC
Date: 2002
Publisher: Springer Science and Business Media LLC
Date: 08-1988
DOI: 10.1007/BF02143548
Publisher: Springer Science and Business Media LLC
Date: 2002
Publisher: CSIRO Publishing
Date: 1992
DOI: 10.1071/AR9920105
Abstract: The effects of tillage practice and double cropping on growth, yield and N economies of summer crops were examined in field experiments near Tamworth, northern New South Wales. Sorghum, sunflower, soybean, mungbean, cowpea and pigeon pea were sown into alkaline, black earth soils which contained either high (Site A, sown January 1983), moderate (Site B, sown December 1983), or low concentrations of nitrate (Site C, sown December 1984). During the previous winters, the land had been sown to wheat (double crop) or fallowed using cultivation or no-tillage practices. At Sites A and B, dry matter yields, averaged over all crops, were increased by 34 and 14% under no-tillage. Average increases in grain yields at the two sites were 22 and 11%. At Site C, tillage practice did not affect yields. Soybean showed the greatest responses to no-tillage. Increases in grain yields were 46, 15 and 18% for Sites A, B and C respectively. The least responsive legume was mungbean. Yields of sorghum were increased by 41% at Site A responses at Sites B and C ranged between a 9% decrease and a 7% increase. With double cropping, grain yields were, on average, 18 (Site A), 81 (Site B) and 72% (Site C) of the yields in the cultivated (fallow) plots. However, when comparisons were made for the 12 month periods, i.e. wheat and summer crops v. fallow and summer crops, production was more than doubled at Site B and tripled at Site C, compared with the cultivated fallow. Significant in the responses to double cropping were the 192 (Site B) and 230 mm rainfalls (Site C) during November and December that replenished the soil profile with water to a depth of .75 m. Assessments of soybean N2 fixation using the ureide method indicated large effects of site and season on the proportion of plant N derived from N2 fixation (range, 0-0.83), on the amount of N2 fixed (range, 0-233 kg N ha-1) and on the N balance as a result of the cropping (range, -69 to +45 kg N ha-1).
Publisher: Elsevier BV
Date: 04-1995
Publisher: Springer Science and Business Media LLC
Date: 02-2009
DOI: 10.1007/BF03179980
Publisher: CSIRO Publishing
Date: 2012
DOI: 10.1071/CP11191
Abstract: Life Cycle Assessment (LCA) has become an increasingly common approach across different industries, including agriculture, for environmental impact assessment. A single-issue LCA focusing on greenhouse gas emissions was conducted to determine the emissions profile and total carbon footprint of wheat produced in the Central Zone (East) of New South Wales. Greenhouse gas emissions (in carbon dioxide equivalents CO2-e) from all stages of the production process, both pre-farm and on-farm, were included. Total emissions were found to be 200 kg CO2-e per t of wheat at the farm gate, based on a 3.5 t/ha grain yield. The relative contribution of greenhouse gas emissions from different components of the production system was determined, with most emissions (37%) coming from pre-farm production and transport of fertiliser (30%) and lime (7%) and from the nitrous oxide (N2O) emitted from the nitrogenous fertiliser applied to the crop (26%). Other important emissions included the CO2 emissions from the use of fertiliser and lime (15%) and the production, transport and use of diesel (16%). The relative importance of other minor emissions is also discussed. For a higher yielding crop (5.0 t/ha), total emissions were found to be 150 kg CO2-e per t of wheat. This paper considers the effect of different management scenarios on the emissions profile and the effect of adopting a N2O emissions factor, which is based on current New South Wales field research, rather than the current Australian National Greenhouse Accounts National Inventory Report default value. This LCA provides a template from which comparative farming systems LCA can be developed and provides data for the Australian Life Cycle Inventory.
Publisher: Elsevier BV
Date: 07-2018
No related grants have been discovered for DAVID HERRIDGE.