Nitrogen responses of canola in low to medium rainfall environments of Western Australia

2016 ◽  
Vol 67 (4) ◽  
pp. 450 ◽  
Author(s):  
Mark Seymour ◽  
Sally Sprigg ◽  
Bob French ◽  
Jackie Bucat ◽  
Raj Malik ◽  
...  

Canola (Brassica napus L.) is widely grown throughout all rainfall zones in south-western Australia. Yields are low by world standards, and variable in low-rainfall (<350 mm annual rainfall) and medium-rainfall (350–450 mm) zones, so that minimising production costs is a major consideration for growers in these areas. One of the major input costs is nitrogen (N) fertiliser. Fifteen N rate × application time × canola plant-type experiments were conducted in the low- and medium-rainfall zones between 2012 and 2014. In most experiments, five rates of N were tested, of ranges 0–75, 0–100, or 0–150 kg N/ha. Nitrogen was applied at four different times (seeding, or 4, 8 or 12 weeks after sowing) or split between these timings. Each experiment compared triazine-tolerant (TT), open-pollinated (OP) canola with Roundup Ready (RR) hybrid canola, and one experiment included TT hybrid and RR OP canola types. On average, RR hybrid produced 250 kg/ha, or 23% more seed and 2.2% more oil than TT OP canola, and the average gross margin of RR hybrid was AU$65/ha more than TT OP. However, seed yield and gross margin differences between RR hybrid and TT OP canola were reduced when seed yields were <1400 kg/ha. Canola growth (dry matter) and seed yield responded positively to N fertiliser in most experiments, with 90% of maximum seed yield achieved at an average of 46 kg N/ha (s.e. 6). However, 90% of maximum gross margin was achieved at a lower average N rate of 17 kg N/ha, due primarily to the relatively small yield increase compared with the reduction in concentration of oil in the seed with N applied. Because canola growers of south-western Australia are now paid an uncapped premium for canola grain with oil concentration >42%, decreases in oil percentage have a significant financial effect, and recommended rates of N should be lower than those calculated to optimise seed yield. In 80% of cases, the first 10 kg N/ha applied provided a return on investment in N >$1.50 for every $1 invested. The next 20 kg N/ha applied provided a return on investment of $1.25 for every $1 invested 80% of the time, and further increases would most likely break even. The timing of N application had a minor effect on yield, oil and financial returns, but delaying N application would allow farmers to reduce risk under poor conditions by reducing or eliminating further inputs. Overall, our work demonstrates that a conservative approach to N supply mindful of the combined impacts of N on yield and oil is necessary in south-western Australia and that split and delayed applications are a viable risk-management strategy.

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1449
Author(s):  
Dasun Premachandra ◽  
Lee Hudek ◽  
Aydin Enez ◽  
Ross Ballard ◽  
Steve Barnett ◽  
...  

Canola (Brassica napus L.) is the third largest crop produced in Australia after wheat and barley. For such crops, the variability of water access, reduced long-term annual rainfall and increasing water prices, higher overall production costs, and variability in production quantity and quality are driving the exploration of new tools to maintain production in an economical and environmentally sustainable way. Microorganisms associated with the rhizosphere have been shown to enhance plant growth and offer a potential way to maintain or even increase crop production quality and yield in an environmentally sustainable way. Here, seven bacterial isolates from canola rhizosphere samples are shown to enhance canola growth, particularly in low water activity systems. The seven strains all possessed commonly described plant growth promoting traits, including the ability to produce indole-3-acetic acid and 1-aminocyclopropane-1-carboxylate deaminase, and the capacity to solubilise nutrients (Fe2+/3+ and PO43−). When the isolates were inoculated at the time of sowing in pot-based systems with either sand or clay loam media, and in field trials, a significant increase in dry root and shoot biomass was recorded compared to uninoculated controls. It is likely that the strains’ plant growth promoting capacity under water stress is due to the combined effects of the bacterial phenotypes examined here.


2020 ◽  
Vol 106 (2) ◽  
pp. 104-111
Author(s):  
V. Kurilo ◽  
◽  
V. Pryshliak ◽  

The article describes the advanced, based on the results of research on the agrophysical properties of plants, technological processes of a non-seedling method of seed production. The agrotechnical techniques developed and proposed for practical use are shown, which provide the increase of seed yield, increase of their coefficient of reproduction and reduction of production costs. The results of the research can be used to improve and optimize zonal technologies and facilities for growing and harvesting sugar beet seed.


2004 ◽  
Vol 44 (9) ◽  
pp. 921 ◽  
Author(s):  
R. F. Brennan ◽  
M. D. A. Bolland

The copper (Cu) requirements of spring wheat (Triticum aestivum L.), the major crop for alkaline soils in south-western Australia, is well known. The Cu requirements of canola (Brassica napus L.), albus lupin (Lupinus albus L.) and durum wheat (Triticum durum L.), alternative crops for these soils, are not known. A glasshouse experiment, using 2 alkaline soils from south-western Australia, compared the yield and Cu content response to applications of Cu to canola, albus lupin, durum wheat and spring wheat. The Cu was applied either just before 45-days incubation in moist soil at 20°C (incubated Cu), or just before sowing after the incubation treatment (current Cu). Comparative Cu requirements were determined from yields of 45-day-old dried shoots for: (i) Cu already present in the soil (indigenous soil Cu); (ii) the amount of applied Cu required to produce the same percentage of the maximum (relative) yield of dried shoots; and (iii) the Cu content of dried shoots (Cu concentration multiplied by yield of dried shoots). The concentration of Cu in youngest tissue and in dried rest of shoots was used to determine critical Cu concentrations in tissue. Albus lupin used indigenous Cu so effectively it only showed a 10% yield increase to applied Cu. Canola used indigenous Cu more effectively than durum wheat, which was followed by spring wheat. Relative to spring wheat, durum wheat was about 15% less effective at using incubated and current Cu to produce dried shoots and canola was about 47% more effective. Therefore, to produce the same percentage of the maximum (relative) yield as spring wheat, durum wheat required about 15% more incubated and current Cu and canola required about 50% less Cu. As determined using Cu content in shoots, canola and durum wheat were about 45% more effective than spring wheat at increasing Cu content in shoots and albus lupin was about 80% more effective. Evidently, all 3 species took up more copper than spring wheat. Durum wheat did not use this Cu to produce more shoot yield than spring wheat, whereas canola did. The critical Cu concentration in the youngest tissue (mg Cu/kg), associated with 90% of the relative yield, was: 1.5 for spring wheat; 1.7 for durum wheat; 1.0 for albus lupin; and 2.2 for canola. Corresponding values (mg Cu/kg) for rest of dried shoots were: 2.5 for spring wheat; 3.2 for durum wheat; 1.3 for albus lupin; and 2.7 for canola.


Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 483
Author(s):  
Esmaeil Zangani ◽  
Kamran Afsahi ◽  
Farid Shekari ◽  
Eileen Mac Sweeney ◽  
Andrea Mastinu

The effects of nitrogen and phosphorus levels on the physiological traits, yield, and seed yield of rapeseed (Brassica napus L.), were studied in a farm research project of Zanjan University. Three levels of nitrogen (0, 100, and 200 kg/ha) and three levels of phosphorus (0, 75, and 150 kg/ha) were considered. The results showed that an increase in nitrogen level caused an increase in the leaf chlorophyll content so that the application of 200 kg/ha of nitrogen increased the chlorophyll content of the leaves until the mid-grain filling stage. Nitrogen application lowered leaf stomatal conductance in the early flowering stage whereas the stomatal conductance was increased during the late flowering stage. Nitrogen application (100 and 200 kg/ha) also increased the quantum yield of photosystem II. On the other hand, with the application of 150 kg/ha and 75 kg/ha of phosphorus, the leaf stomatal conductance and the quantum yield of photosystem II in the early flowering stage increased respectively. The results showed that the application of 200 kg/ha of nitrogen and 75 kg/ha of phosphorus significantly increased seed and oil yield compared to the control. In addition, the number of siliques per plant and the weight of 1000 seeds showed an increasing trend that was affected by nitrogen and phosphorus levels. This study demonstrated that nitrogen enhanced the chlorophyll content, leaf area, and consequently, the quantum yield of photosystem II. Nitrogen also augmented the seed filling duration, seed yield, and oil yield by increasing gas exchange. As a result, the application of 100 kg/ha of nitrogen together with 75 kg/ha phosphorus showed the greatest effect on the qualitative and quantitative yield of rapeseed. However, the application of 200 kg/ha of nitrogen alone or in combination with different levels of phosphorus did not significantly increase many of the studied traits.


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 605
Author(s):  
Peder K. Schmitz ◽  
Hans J. Kandel

Planting date (PD), seeding rate (SR), relative maturity (RM) of cultivars, and row spacing (RS) are primary management factors affecting soybean (Glycine max (L.) Merr.) yield. The individual and synergistic effects of PD, SR, RM, and RS on seed yield and agronomic characteristics in North Dakota were herein investigated. Early and late PD, early and late RM cultivars, two SR (408,000 and 457,000 seed ha−1), and two RS (30.5 and 61 cm) were evaluated in four total environments in 2019 and 2020. Maximizing green canopy cover prior to the beginning of flowering improved seed yield. Individual factors of early PD and narrow RS resulted in yield increase of 311 and 266 kg ha−1, respectively. The combined factors of early PD, late RM, high SR, and narrow RS improved yield by 26% and provided a $350 ha−1 partial profit over conventional practices. Canopy cover and yield had relatively weak relationships with r2 of 0.36, 0.23, 0.14, and 0.21 at the two trifoliolate, four trifoliolate, beginning of flowering, and beginning of pod formation soybean growth stages, respectively. Producers in the most northern soybean region of the USA should combine early planting, optimum RM cultivars, 457,000 seed ha−1 SR, and 31 cm RS to improve yield and profit compared to current management practices.


Agronomy ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 77 ◽  
Author(s):  
Aung Zaw Htwe ◽  
Seinn Moh Moh ◽  
Khin Myat Soe ◽  
Kyi Moe ◽  
Takeo Yamakawa

The use of biofertilizers is important for sustainable agriculture, and the use of nodule bacteria and endophytic actinomycetes is an attractive way to enhance plant growth and yield. This study tested the effects of a biofertilizer produced from Bradyrhizobium strains and Streptomyces griseoflavus on leguminous, cereal, and vegetable crops. Nitrogen fixation was measured using the acetylene reduction assay. Under N-limited or N-supplemented conditions, the biofertilizer significantly promoted the shoot and root growth of mung bean, cowpea, and soybean compared with the control. Therefore, the biofertilizer used in this study was effective in mung bean, cowpea, and soybean regardless of N application. In this study, significant increments in plant growth, nodulation, nitrogen fixation, nitrogen, phosphorus, and potassium (NPK) uptake, and seed yield were found in mung beans and soybeans. Therefore, Bradyrhizobium japonicum SAY3-7 plus Bradyrhizobium elkanii BLY3-8 and Streptomyces griseoflavus are effective bacteria that can be used together as biofertilizer for the production of economically important leguminous crops, especially soybean and mung bean. The biofertilizer produced from Bradyrhizobium and S. griseoflavus P4 will be useful for both soybean and mung bean production.


2002 ◽  
Vol 42 (6) ◽  
pp. 717 ◽  
Author(s):  
R. A. Sudmeyer ◽  
P. R. Scott

This paper, which is the second in a series of three, describes dryland crop growth and yields in a windbreak bay in south-western Australia and relates changes to microclimate modification by the windbreaks. Over the 4 years of this trial, above ground biomass and the development rate of crops 3–20 times the tree height from the windbreak (H) were similar to crops growing in unsheltered conditions (more than 20 H from the windbreaks). Grain yield was 16–30% higher between 3 H and 20 H than at more than 20 H in 1994, the driest year on record for the district, in other years yield was largely unchanged. In contrast, above ground biomass growth was consistently less within 3 H than further from the windbreaks and grain yield within 3 H was 19–27% less than unsheltered yield. Water use by the trees is the most likely cause of reduced yield within 3 H. Over the 4 years, mean grain yield between 0.5 H and 20 H was 3.8% greater than yield at more than 20 H. This increase was largely due to the yield increase in 1994. As 5.4% of the paddock was directly occupied by, or uncropped next to, the windbreaks, there was a net yield decrease of 2.8% over 4 years compared to estimated production from a similar area with no windbreaks. The principle benefits of the windbreaks were reducing evaporative demand in extremely dry years and protection against extreme wind events. These benefits must be weighed against the costs of establishing and maintaining windbreak systems.


2012 ◽  
Vol 40 (2) ◽  
pp. 210 ◽  
Author(s):  
Hamid MADANI ◽  
Mohammad Ali MALBOOBI ◽  
Kioomars BAKHSHKELARESTAGHI ◽  
Agnieszka STOKLOSA

A field experiment was conducted for investigation of different phosphorus fertilizer sources and their importance in rapeseed farms on 2007 at Arak, Iran. Ammonium phosphate fertilizer with 50% P2O5 (APF) was as chemical phosphorus sources with 3 rates of application and Phosphor solublizing bacteria (PSB) was as biological phosphorus surcease in 4 levels. Experiment was factorial arrangement in randomized complete block design with 3 replications. APF levels were control (AP0), 125kg/ha APF (AP1) and 250kg/ha (AP2) application and PSB levels were, control (PSB0), PSB at sowing time only (PSB1), PSB as top dress fertilizer after over wintering only (PSB2) and PSB at dual fertilizing in sowing time and also after over wintering (PSB3). The statistical analyses were showed that the PSB3 treatment was a great treatment for increasing seed yield. The heist rate of seed yield was recorded at 9.9t/ha under dual fertilizing in sowing time and after rosette over wintering stage. The interaction effects of phosphorus solublizing bacteria and ammonium phosphate fertilizer application had not significant effect on plant height, biomass yield, number of silique per plant, seed oil percent and seed yield. Interaction effects of phosphorus solublizing bacteria and ammonium phosphate fertilizer application were significant for plant tissues phosphorus content.


Author(s):  
Fen Gao ◽  
Yuanhong Chen ◽  
SeaRa Lim ◽  
Allen Xue ◽  
Bao-Luo Ma

Effective nitrogen (N) management strategies are important for ensuring a balance between optimizing plant growth and minimizing disease damage. A field experiment was conducted for three years to (i) assess the effects of N fertilizer application on the growth and seed yield of canola, and severities of Sclerotinia stem rot (SSR), and (ii) determine a reasonable N-rate for optimizing plant growth and minimizing the loss from SSR in eastern Canada. The experiment was designed with factorial combinations of eight N treatments and two canola hybrids. All N-treatments reduced canola emergence with increasing preplant N application rates above 100 kg ha–1, but had a positive impact on plant height, fresh weight, dry weight and seed yield. The development of SSR showed differential responses to N application rates. Of all the treatments, the split application (50 kg N ha–1 at preplant plus 100 kg N ha–1 side-dressed at the 6-leaf stage) increased canola growth, and often produced the highest or similar seed yields to those of equivalent N rate applied as preplant. At the 150 kg ha–1 N rate, no severe development of SSR was observed in either preplant-only or split application. Overall, this study demonstrates that the split-N management strategy (50+100 kg ha–1) maintained a balance between enhancing plant growth and mitigating the negative impacts of SSR on canola.


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