Wheat and canola response to concentrations of phosphorus and cadmium in a sandy soil

2004 ◽  
Vol 44 (10) ◽  
pp. 1025 ◽  
Author(s):  
R. F. Brennan ◽  
M. D. A. Bolland

An old phosphate rock experiment was used to determine critical Colwell soil test phosphorus values for spring wheat (Triticum aestivum L.) and canola (rape, Brassica napus L.). Different amounts of phosphorus, applied to the soil 16 years previously as triple superphosphate and phosphate rock fertilisers, and different amounts of triple superphosphate applied in the current year, were used to generate soil with different P status. The phosphorus fertilisers contained different concentrations of cadmium as an impurity. The experiment was thus used to relate soil test cadmium, measured using 0.005 mol CaNO3/L, to cadmium concentration in grain. Colwell soil test phosphorus, related to 90% of the maximum grain yield (critical value), was 58 mg phosphorus/kg soil for wheat and 19 mg phosphorus/kg soil for canola. In soil with low Colwell phosphorus concentrations, canola efficiently used phosphorus that was banded with the seed while sowing (drilled phosphorus), requiring 15 kg phosphorus/ha as triple superphosphate to achieve 90% of the maximum yield, compared to 65–70 kg phosphorus/ha for wheat. Soil test cadmium was highly correlated with grain cadmium in both wheat (R2 = 0.89) and canola (R2 = 0.96), suggesting soil testing for cadmium may be used to predict the likelihood of grain cadmium contamination.

2006 ◽  
Vol 46 (5) ◽  
pp. 645 ◽  
Author(s):  
M. D. A. Bolland ◽  
R. F. Brennan ◽  
P. F White

The phosphorus (P) requirements of spring wheat (Triticum aestivum L.) are well known for all soils in south-western Australia; but the P requirements of field pea (Pisum sativum L.) and canola (Brassica napus L.), which are grown in rotation with wheat on marginally acidic to alkaline soils in the region, are not known. In a glasshouse study, the P requirements of field pea and wheat were compared for 16 soils collected throughout the agricultural region. Ten of the 16 soils were also used to compare the P requirements of canola and wheat. The P was applied as powdered single superphosphate, and yield of dried shoots of 42-day-old plants was measured. The amount of P required to produce 90% of the maximum yield of dried shoots (PR90 values) was used to compare the P requirements of the species. To produce 90% of the maximum yield, field pea required less P than wheat in 5 soils, similar P in 2 soils, and more P in 9 soils. Canola required less P than wheat in all 10 soils. We conclude the P requirements of field pea or canola relative to wheat depend on a complex interaction between plant and soil, particularly for field pea relative to wheat. Per unit of applied P, the P concentration in dried shoots decreased in the order canola > wheat > field pea, indicating the order in which plant roots of the 3 species were able to access P from soil.


2020 ◽  
Vol 71 (12) ◽  
pp. 959
Author(s):  
Malcolm R. McCaskill ◽  
Penny Riffkin ◽  
Amanda Pearce ◽  
Brendan Christy ◽  
Rob Norton ◽  
...  

Nutrient deficiencies are considered a reason for commercial yields of wheat (Triticum aestivum L.) and canola (Brassica napus L.) in the high-rainfall zone (HRZ) of southern Australia being well below predicted potential yields. With the aim of developing soil-test interpretation guidelines suitable for HRZ conditions, nutrient-response experiments, 15 with wheat and 12 with canola, were conducted between 2015 and 2018. These experiments quantified responses to nitrogen (N), phosphorus (P), potassium (K), sulfur (S), copper (Cu) and zinc (Zn) in pre-sowing soil tests. The highest yielding treatment of the wheat experiments averaged 7.1 t/ha (range 2.6–10.8 t/ha), and of the canola experiments 4.2 t/ha (range 0.7–6.2 t/ha). The most frequent responses were to N and P, followed by S and K. There were no significant positive responses to Cu or Zn. Across the experiments, the 95% critical value for Colwell P in wheat was 52 mg/kg, with a 95% confidence range of 39–68 mg/kg. For canola, the critical value was 59 mg/kg, with a range of 38–139 mg/kg. These values are higher than from lower rainfall regions of Australia. Critical values for K and S were also higher than from drier regions of Australia. The Sprengel–Lieberg Law of the Minimum overestimated yield where there were multiple nutrient limitations, whereas an equivalent Law of the Product underestimated yield under these conditions. These higher critical values based on evidence from the HRZ are expected to assist in closing the yield gap for wheat and canola in the region.


2007 ◽  
Vol 58 (4) ◽  
pp. 359 ◽  
Author(s):  
R. F. Brennan ◽  
M. D. A. Bolland

Most sandy soils used for cropping in south-western Australia are now deficient in potassium (K) due to removal of K from soil in hay and grain, and profitable grain yield responses to applied fertiliser K are commonly obtained for spring wheat (Triticum aestivum L.) and canola (oilseed rape, Brassica napus L.). However, there are only limited data comparing the K requirements of these 2 species in the region. In a glasshouse experiment we compared the K requirements of wheat (cv. Westonia), conventional canola cv. Outback (cultivars of canola not produced by classical breeding techniques to be tolerant of specific herbicides), triazine-tolerant (TT) canola cvv. Pinnacle and Surpass 501, and imidazolinone-tolerant (IT) canola cv. Surpass 603. The following measures were used: yield of 54-day-old dried shoots and seed (grain) without added K, applied K required to produce 90% of the maximum yield of shoots and grain, K required to attain a K concentration in shoots of 30 g/kg, and K required to achieve a K content in shoots (K concentration multiplied by yield) of 40 mg/pot. We also determined for each species and cultivar the concentration of K in dried shoots that was related to 90% of the maximum grain yield, to estimate critical concentration in shoots below which K deficiency was likely to reduce grain production. All 4 canola cultivars produced similar results. Both canola and wheat produced negligible shoot yields and no grain when no K was applied. For each species and cultivar the amount of applied K required to produce 90% of the maximum yield was similar for shoots and grain, and was ~121 mg K/pot for the 4 canola cultivars and 102 mg K/pot for wheat, so ~19% more K was required for canola than for wheat. For each amount of K applied, the concentration of K in shoots was greater for canola than for wheat. The amount of applied K required to attain a K concentration of 30 g K/kg in shoots was ~96 mg K/pot for canola and 142 mg K/pot for wheat, so ~48% more K was required by wheat than by canola. The amount of K applied required to achieve a K content of 40 mg K/pot in shoots was ~46 mg K/pot for canola and 53 mg K/pot for wheat, so ~13% more applied K was required by wheat than by canola. The data suggest that canola roots were better able to obtain K from soil than wheat roots, but wheat used the K taken up more effectively than canola to produce shoots and grain. The concentration of K in dried shoots of 54-day-old plants that was related to 90% of the maximum dried shoot yield or grain was ~32 g/kg for canola and ~23 g/kg for wheat.


2013 ◽  
Vol 64 (5) ◽  
pp. 523 ◽  
Author(s):  
Geoffrey C. Anderson ◽  
Ken I. Peverill ◽  
Ross F. Brennan

Accurate definition of the sulfur (S) soil test–crop grain yield increase (response) relationship is required before soil S test measurements can be used to if there are likely to be responses to S fertilisers. An analysis was done using the Better Fertiliser Decision for Crops (BFDC) National Database using a web application (BFDC Interrogator) to develop calibration relationships between soil S tests (KCl-40 and MCP) using a selection of sampling depths and grain relative yields (RY). Critical soil test values (CSTV) and critical soil test ranges (CSTR) were defined at RY 90%. The ability of the KCl-40 extractable S soil test to predict grain yield response to applied S fertiliser was examined for wheat (Triticum aestivum L.) grown in Western Australia (WA), New South Wales (NSW), and Victoria and canola (Brassica napus L.) grown in WA and NSW. A smaller dataset using MCPi-extractable S was also assessed. The WA-grown wheat KCl-40 S CSTV, using sampling depth to 30 cm for soil types Chromosols (Coloured), Chromosols (Sesqui-Nodular), Kandosols (Grey and Yellow), Tenosols (Brown and Yellow), and Tenosols (Grey, Sesqui-Nodular), was 2.8 mg kg–1 with an associated CSTR 2.4–3.2 mg kg–1 and a correlation coefficient (r) 0.87. Similarly, KCl-40 S CSTV was defined using sampling depth to 10 cm for these selected soil types and for wheat grown on Vertosols in NSW. The accuracy of the KCl-40 S CSTV for canola grown in WA was improved using a sampling to a depth of 30 cm instead of 10 cm for all soil types. The canola KCl-40 S CSTV using sampling depth to 30 cm for these soil types was 7.2 mg kg–1 with an associated CSTR 6.8–7.5 and an r value 0.70. A similar KCl-40 S CSTV of 7.0 mg kg–1 was defined using a sampling depth of 10 cm, but the CSTR was higher (6.4–7.7 mg kg–1) and the r value lower (0.43). A lower KCl-40 S CSTV of 3.9 mg kg–1 or 31.0 kg ha–1 using a sampling depth of 60 cm was defined for canola grown in NSW using a limited number of S-rate calibration treatment series. Both MCPi (r = 0.32) and KCl-40 (r <0.20) soil S test–NSW canola response relationships using a 0–10 cm sampling depth were weak. The wheat KCl-40 S CSTR of 2.4–3.2 mg kg–1 can be used widely on soil types where soil sulfate is not leached during the growing season. However, both the WA canola CSTR of 6.4–7.2 mg kg–1 using a sampling depth of 30 cm and NSW canola CSTR of 25–39 kg ha–1 or 3.1–4.9 mg kg–1 using a sampling depth of 60 cm can be considered in regions outside of WA and NSW.


2006 ◽  
Vol 46 (5) ◽  
pp. 675 ◽  
Author(s):  
R. F. Brennan ◽  
M. D. A. Bolland

The predominantly sandy soils of south-western Australia have become potassium (K) deficient for spring wheat (Triticum aestivum L.) production due to the removal of K from soil in grain and hay. The K requirements of canola (rape, Brassica napus L.) grown in rotation with wheat on these soils are not known and were determined in the study reported here. Seed (grain) yield increases (responses) of canola to applications of fertiliser K occurred at sites where Colwell soil test K values (top 10 cm of soil) were <60 mg/kg soil. Grain yield responses to applied K occurred when concentrations of K in dried shoots were <45 g/kg for young plants 7 and 10 weeks after sowing and <35 g/kg for 18 weeks after sowing. Application of fertiliser K had no significant effects on either oil or K concentrations in grain.


2004 ◽  
Vol 44 (3) ◽  
pp. 309 ◽  
Author(s):  
R. F. Brennan ◽  
M. D. A. Bolland

We compared the potassium (K) response of canola (Brassica napus L. cv. Karoo), spring wheat (Triticum aestivum L. cv. Camm), narrow-leaf lupin (8 cultivars of Lupinus angustifolius L.), and yellow lupin (2 cultivars of L. luteus L.) in a glasshouse experiment. The following measures were used: yield without added K; K required for 75% of the maximum yield; K required to achieve a K concentration in shoots of 20 g/kg; K required to achieve a K content of 50 mg K/pot in dried shoots (K concentration multiplied by yield); and, for the L. angustifolius cultivars, the K efficiency ratio (yield for the nil-K treatment divided by yield for the largest amount of K applied).Both L. angustifolius and L. luteus used soil K and applied K more effectively than canola and wheat to produce shoots (measured from dried shoots of 42-day old seedlings). For all amounts of K applied, including the nil treatment, the K concentrations were higher in canola and wheat shoots than in shoots of the 2 lupin species. Consequently, the 2 lupin species were less effective than canola and wheat at taking up soil and applied K, but were more effective at using the K taken up to produce shoots. The most recent cultivar of L. angustifolius, cv. Kalya, was less effective than the older Merrit cultivar at using soil and applied K to produce shoots, therefore future cultivars need to be screened for their ability to use soil and applied K. The K efficiency ratio for L. angustifolius indicated cultivars Kalya and 2141 were inefficient and the following cultivars had similar medium efficiency values: Myallie, Tanjil, Tallerack, Quilinock, Belara and Merrit. As measured in 42 day old seedlings, the diagnostic critical concentration of K in shoots required for 90% maximum yield of dried shoots was about (g K/kg) 40 for wheat, 37�for canola, 16 for L. angustifolius and 14 for L. luteus.


1984 ◽  
Vol 64 (3) ◽  
pp. 369-381 ◽  
Author(s):  
M. GIROUX ◽  
A. DUBE ◽  
G. M. BARNETT

The effect of phosphorus fertilization on potato yields (Solanum tuberosum L.) was studied on 24 experimental sites varying from 44 to 1000 kg/ha of soil test P. The respective relative yields (yield with P fertilizer/maximum yield with P fertilizer x 100) varied from 20.3 to 100%. The Mitscherlich equation was used to relate relative yields to soil test P. According to their soil test value, the soils were partitioned in three classes by the Cate-Nelson method to establish poor (300 kg/ha of available P or less), medium (301–400 kg/ha P) and rich 401 kg/ha P or more) soil fertility classes. It was found that 94 kg/ha fertilizer P was necessary for maximum yields with an increase of 10% or greater on poor soils. On medium and rich soils, the requirement was 50 kg P/ha for a yield increase of 1–10%. Below a 1% increase, the P application should be lowered. At high rates diammonium phosphate (DAP) has been found to give tuber yield equal to those of superphosphates. On the other hand, at low rates, DAP application was more effective. DAP induced a higher mid-season P concentration in the petiole tissue Acidification by superphosphates increased aluminum, iron and manganese availability in the soil and reduced P solubility in the band area, in contrast to DAP. Key words: Potato, soil test phosphorus, source of phosphorus fertilizer, phosphorus fertilization, superphosphate, ammonium phosphate


2006 ◽  
Vol 46 (8) ◽  
pp. 1061 ◽  
Author(s):  
R. F. Brennan ◽  
M. D. A. Bolland

The sulfur (S) requirements of canola (Brassica napus L.) grown in rotation with spring wheat (Triticum aestivum L.) and lupin (Lupinus angustifolius L.) in south-western Australia are not known. This study, involving 59 experiments, was conducted from 1993 to 2003 to determine soil and tissue test values for canola grain production below which S deficiency is likely. Extraction of S from soil using 0.25 mol KCl/L at 40°C (KCl-40 procedure) for the top 10 cm of soil is the standard soil test for S in the region. We measured KCl-40 values for soil samples collected at soil depths of 0–10, 10–20 and 20–30 cm and related the values to canola grain yield responses to applied fertiliser S measured at the end of the growing season. Total S measured in dried shoots at about 90 days after sowing (DAS) was related to shoot yields at 90 DAS and grain yields. In addition, the concentration of oil in canola grain was measured to see if applications of S affected oil concentrations. Soil test S was higher in the subsoil than in the top 10 cm of soil at about half the sites comprising sandy duplex soils with larger capacities to sorb sulfate in the subsoil. Significant grain yield responses to applied S occurred for soil test values <7 mg/kg to 30 cm. At many sites when soil test S was <7 mg/kg in the top 10 cm of soil, shoots showed grain yield responses to applied S, but canola roots eventually accessed sufficient S in the subsoil for grain production, so that no grain yield responses to applied fertiliser S occurred. Therefore, tissue test values for dried shoots at 90 DAS poorly predicted S deficiency for grain production. Responses of shoots and grain to applied S occurred for S concentrations in shoots <4 g/kg. We conclude that shallow soil tests and early tissue testing may both overestimate the magnitude of an S deficiency for grain production of canola grown in sandy WA soils. Deeper soil tests need to be seriously considered. Applications of fertiliser S mostly had no consistent effect on concentrations of oil in canola grain.


Author(s):  
P.W. Shannon

Increasing material, processing, and distribution costs have raised superphosphate prices to a point where many farms cannot support the costs of meeting maintenance phosphate requires men& Alternatives to superphosphate, particularly those that have lower processing costs and contain more P, may offer a solution to the problem provided they are agronomically as effective. Phosphate rock may indeed be such an alternative. Preliminary results from a series of five trials in Northland show that on soils of moderate P fertility, with low phosphate retention (PR) and high pH (5.9.6.0), initial pasture growth responses to rock phosphates are smaller than those from single or triple superphosphate. On one soil of higher PR and lower pH, the differences in yield between the rock-phosphates and the super. phosphates were smaller. Of the rock phosphates tested, Sechura and North Carolina (unground and ungranulated) tended to be more effective than ground and granulated Chatham Rise phosphorite. The effect on production of applying fertilisers once every three years, as opposed to annual applications is being investigated using triple superphosphate and Sechura phosphate rock. After two years, production levels appear largely unaffected by differences in application frequency. A comparison of locally-produced superphosphate with a reference standard showed that both performed similarly, indicating that the local product was of satisfactory quality.


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