The effect of irrigation and nitrogen fertilizer on rapeseed (Brassica napus) production in South-Eastern Australia

1988 ◽  
Vol 9 (1) ◽  
pp. 15-25 ◽  
Author(s):  
C. J. Smith ◽  
G. C. Wright ◽  
M. R. Woodroofe
Keyword(s):  
Brassica Napus ◽  
Nitrogen Fertilizer ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

Re-evaluating sowing time of spring canola (Brassica napus L.) in south-eastern Australia—how early is too early?

2016 ◽  
Vol 67 (4) ◽  
pp. 381 ◽  
Author(s):  
J. A. Kirkegaard ◽  
J. M. Lilley ◽  
R. D. Brill ◽  
S. J. Sprague ◽  
N. A. Fettell ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Oil Content ◽  
Yield Variability ◽  
Sensitivity Index ◽  
Brassica Napus L ◽  
South Eastern ◽  
Spring Canola ◽  
Sowing Dates ◽  
Eastern Australia ◽  
South Eastern Australia

Optimising the sowing date of canola (Brassica napus L.) in specific environments is an important determinant of yield worldwide. In eastern Australia, late April to early May has traditionally been considered the optimum sowing window for spring canola, with significant reduction in yield and oil in later sown crops. Recent and projected changes in climate, new vigorous hybrids, and improved fallow management and seeding equipment have stimulated a re-evaluation of early-April sowing to capture physiological advantages of greater biomass production and earlier flowering under contemporary conditions. Early–mid-April sowing generated the highest or equal highest yield and oil content in eight of nine field experiments conducted from 2002 to 2012 in south-eastern Australia. Declines in seed yield (–6.0% to –6.5%), oil content (–0.5% to –1.5%) and water-use efficiency (–3.8% to –5.5%) per week delay in sowing after early April reflected levels reported in previous studies with sowings from late April. Interactions with cultivar phenology were evident at some sites depending on seasonal conditions. There was no consistent difference in performance between hybrid and non-hybrid cultivars at the earliest sowing dates. Despite low temperatures thought to damage early pods at some sites (<−2°C), frost damage did not significantly compromise the yield of the early-sown crops, presumably because of greater impact of heat and water-stress in the later sown crops. A validated APSIM-Canola simulation study using 50 years of weather data at selected sites predicted highest potential yields from early-April sowing. However, the application of a frost-heat sensitivity index to account for impacts of temperature stress during the reproductive phase predicted lower yields and higher yield variability from early-April sowing. The frost–heat-limited yields predicted optimum sowing times of mid-April at southern sites, and late April to early May at the northern sites with lower median yield and higher yield variability in crops sown in early April. The experimental and simulation data are potentially compatible given that the experiments occurred during the decade of the Millennium drought in south-eastern Australia (2002–10), with dry and hot spring conditions favouring earlier sowing. However, the study reveals the need for more accurate and validated prediction of the frost and heat impacts on field-grown canola if simulation models are to provide more accurate prediction of attainable yield as new combinations of cultivar and sowing dates are explored.

scholarly journals Tillage does not increase nitrous oxide emissions under dryland canola (Brassica napus L.) in a semiarid environment of south-eastern Australia

Soil Research ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 512 ◽  
Author(s):  
Guangdi D. Li ◽  
Mark K. Conyers ◽  
Graeme D. Schwenke ◽  
Richard C. Hayes ◽  
De Li Liu ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Brassica Napus ◽  
N2o Emission ◽  
Nitrous Oxide Emissions ◽  
Annual Rainfall ◽  
N2o Emissions ◽  
Brassica Napus L ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

Dryland cereal production systems of south-eastern Australia require viable options for reducing nitrous oxide (N2O) emissions without compromising productivity and profitability. A 4-year rotational experiment with wheat (Triticum aestivum L.)–canola (Brassica napus L.)–grain legumes–wheat in sequence was established at Wagga Wagga, NSW, Australia, in a semiarid Mediterranean-type environment where long-term average annual rainfall is 541mm and the incidence of summer rainfall is episodic and unreliable. The objectives of the experiment were to investigate whether (i) tillage increases N2O emissions and (ii) nitrogen (N) application can improve productivity without increasing N2O emissions. The base experimental design for each crop phase was a split-plot design with tillage treatment (tilled versus no-till) as the whole plot, and N fertiliser rate (0, 25, 50 and 100kgN/ha) as the subplot, replicated three times. This paper reports high resolution N2O emission data under a canola crop. The daily N2O emission rate averaged 0.55g N2O-N/ha.day, ranging between –0.81 and 6.71g N2O-N/ha.day. The annual cumulative N2O-N emitted was 175.6 and 224.3g N2O-N/ha under 0 and 100kgN/ha treatments respectively. There was no evidence to support the first hypothesis that tillage increases N2O emissions, a result which may give farmers more confidence to use tillage strategically to manage weeds and diseases where necessary. However, increasing N fertiliser rate tended to increase N2O emissions, but did not increase crop production at this site.

Effect of sowing date and seeding rate on yield and yield components of irrigated canola (Brassica napus L.) grown on a red-brown earth in south-eastern Australia

1992 ◽  
Vol 43 (7) ◽  
pp. 1629 ◽  
Author(s):  
AJ Taylor ◽  
CJ Smith
Keyword(s):  
Brassica Napus ◽  
Seed Yield ◽  
Sowing Date ◽  
Strongly Correlated ◽  
Seeding Rate ◽  
Brassica Napus L ◽  
South Eastern ◽  
Sowing Dates ◽  
Eastern Australia ◽  
South Eastern Australia

Response of canola (Brassica napus) to factorial combinations of five sowing dates and seeding rates was investigated from 1987 to 1989. The experiments were conducted on red-brown earths in the Goulburn-Murray Irrigation Region of south-eastern Australia. Crops were sown at monthly intervals beginning in April each year. In 1987, seeding rates were 4.6, 7.0 and 14 kg ha-1, but in 1988 and 1989 the lowest rate was eliminated. The cultivar Marnoo was used each year and Eureka was included in 1989. There was no difference between yields of seed and oil for crops sown in April and May, but yields of seed and oil declined when sowing date was delayed beyond May. Oil contents were greater than 45% for the April, May and June sowings in 1988 and 1989. In contrast, seeding rates had no effect on yields of seed and oil. Marnoo produced a maximum seed yield of 398 g m-2 from the May sowing in 1987, and a minimum seed yield of 172 g m-2 from the September sowing in 1988. In 1989, Eureka out-yielded Marnoo in all but the August sowing. Eureka produced a maximum seed yield of 483 g m-2 from the April sowing and its lowest seed yield of 315 g m-2 from the August sowing. The number of pods per m2 was the major factor responsible for the significant changes in yield in all experiments. Seed yield was also strongly correlated (P < 0.01) with biomass, and to a lesser degree, with individual seed weight in all comparisons with the exception of Marnoo in 1989.

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