Field studies of cadmium in potatoes (Solanum tuberosum L.). III. Response of cv. Russet Burbank to sources of banded potassium

1994 ◽  
Vol 45 (1) ◽  
pp. 243 ◽  
Author(s):  
LA Sparrow ◽  
AA Salardini ◽  
J Johnstone

Six field experiments were conducted where Russet Burbank potatoes were grown with banded fertilizer consisting of diammonium phosphate (DAP) and either potassium sulfate (K2S04) or potassium chloride (KCl). At each site, rates of nitrogen (N), phosphorus (P) and potassium (K) were matched as closely as possible for each K fertilizer treatment. At four of the six sites, potatoes grown with K2S04 had tuber and petiole cadmium (Cd) concentrations 20-30% lower than did potatoes grown with KCl. The use of K2S04 instead of KCl appears to offer considerable promise as a means of decreasing tuber Cd uptake. Sulfate ions presumably promote increased soil adsorption of soil and/or fertilizer Cd compared with chloride ions, and so decrease Cd availability. We attributed the lack of difference in tuber and petiole Cd between K sources at two sites to either leaching, chloride in irrigation water, or at one site to a higher than desired rate of NPK fertilizer with the sulfate treatment. Any one of these may have offset decreases in Cd uptake due to the presence of sulfate ions.


1993 ◽  
Vol 44 (4) ◽  
pp. 845 ◽  
Author(s):  
LA Sparrow ◽  
AA Salardini ◽  
AC Bishop

Field experiments were conducted at three sites on basaltic krasnozems to examine cadmium (Cd) responses of Russet Burbank potatoes to different rates of broadcast lime and banded phosphorus (P). Double superphosphate (DSP, containing 15 and 90 mg Cd kg-1) and triple superphosphate (TSP, 12 mg Cd kg-1)) were the sources of P. In a fourth experiment, lime was banded with the basal fertilizer. Despite producing a range of topsoil pH (1:5 H20) of 5.2 to 7.1, broadcast lime had no effect on tuber Cd concentrations. Lime had no effect when banded with the basal fertilizer, and the practice did not adversely affect yields. With broadcast lime, Cd availability from the fertilizer band may have been unaffected. However, there were also no lime x P interactions at any site, suggesting that lime also had no effect on the availability of Cd in the soil. It is possible that Tasmanian krasnozems, with their high organic matter and iron oxide content, restrict the availability of Cd in the soil such that pH change exerts little net influence on Cd availability. Increasing amounts of Cd applied in P fertilizer increased tuber Cd concentrations significantly, but the increases were less per unit of P than those found previously when TSP with 151 mg Cd kg-1) was used.



1993 ◽  
Vol 44 (4) ◽  
pp. 855 ◽  
Author(s):  
LA Sparrow ◽  
AA Salardini ◽  
AC Bishop

Separate field experiments were conducted with Russet Burbank and Kennebec potatoes on a basaltic krasnozem where tuber cadmium (Cd) responses were examined over three rates of banded phosphorus (P), supplied as double superphosphate (DSP) containing either 15 or 90 mg Cd kg-1. In both cultivars, tuber Cd concentrations increased with rate of DSP. This response was due more to the amount of P supplied in the DSP than the amount of Cd supplied in the DSP and may be a result of banded P encouraging root proliferation in the fertilizer band. Even with DSP at 15 mg Cd kg-1, Cd additions at rates of DSP needed for high yields were 6-20 times higher than corresponding rates of Cd removal in tubers. Examination of data from all studies of Cd in Russet Burbank on Tasmanian krasnozems showed a significant relationship between petiole and tuber Cd concentrations, but the estimation of a petiole concentration associated with the critical tuber Cd concentration in Australia was subject to unacceptable uncertainty due to variation between sites.



1991 ◽  
Vol 31 (3) ◽  
pp. 393
Author(s):  
NA Maier ◽  
AB Frensham ◽  
KSR Chapman ◽  
CMJ Williams

Total tuber yields were compared for inner and outer (guard) rows from 4 phosphorus (P) and 3 nitrogen (N) field experiments conducted during 1985-86 in South Australia, and from 5 N and 2 potassium (K) field experiments conducted during 1985-86 and 1987-88 in Tasmania. All fertiliser treatments were banded along the rows, either at planting or part at planting and the remainder sidedressed after emergence. The inter-row spacings were in the range 76-86 cm and the cultivars used were Kennebec, Coliban and Russet Burbank. Analysis showed that at only 1 of the 14 sites (site 6 in South Australia) was the mean total tuber yield for the inner 2 rows significantly (P<0.01) less than the mean total tuber yield for all 4 rows. However, the difference was small (0.8 t/ha or 1.9%) and of little practical importance. The relationships between mean (� s.e.) total tuber yield and rate (kg/ha) of applied nutrient (0-240 P, 0-320 N, 0-400 K) for inner and guard rows showed that differences between means were small and usually within standard error ranges at all sites. There were no consistent differences in the magnitudes of the standard errors of the means for inner and guard rows for all rates and types of nutrient applied. No significant cross-feeding occurred in these fertiliser experiments, which suggests that omission of guard rows from experiments where the fertiliser treatments are applied along the rows should not result in serious errors of interpretation of tuber yield response.



1989 ◽  
Vol 69 (2) ◽  
pp. 601-609 ◽  
Author(s):  
D. C. MacKAY ◽  
T. ENTZ ◽  
J. M. CAREFOOT ◽  
S. DUBETZ

Best fit quadratic response curves relating tuber yields with fertilizer treatment rates from a 3-yr 4 × 4 factorial field experiment provided the bases for diagnosing nutrient deficiencies of N and P. These curves were compared with similar response curves of leaf nutrient concentrations and for deficiency indices calculated by the Diagnosis and Recommendation Integrated System (DRIS). Critical nutrient concentrations (CNCs) of 5.93 and 5.44% of N and 0.47 and 0.35% of P were associated with estimated yield decrements of < 5% and > 15% of the maxima. Corresponding DRIS indices were −2.1 and −6.7 for N and −10 and −26 for P. Although there were no yield responses to applied K in 10 field experiments, 4 and 3% were selected as CNCs possibly indicative of K-supplying potential. Corresponding DRIS values were 5.6 and −17. When these CNC values were applied to 372 commercial fields sampled over an 8-yr period, there were 30, 44, and 12% in the top class for N, P, and K, respectively, while 34, 8, and 7% were in the bottom deficiency class. The DRIS system placed 41, 76, and 76% of the fields in the same deficiency classes for N, P, and K, respectively, but only 13, 0, and 0% differed by more than one class. There appeared to be limited potential advantages for the DRIS method of diagnosis.Key words: Solanum tuberosum L., leaf analysis, fertilizer rates, potato.



1992 ◽  
Vol 32 (1) ◽  
pp. 113 ◽  
Author(s):  
LA Sparrow ◽  
KSR Chapman ◽  
D Parsley ◽  
PR Hardman ◽  
B Cullen

Four field experiments were conducted to examine the yield response and cadmium (Cd) concentration of potatoes (Solanum tuberosum L. cv. Russet Burbank) grown with banded or broadcast phosphorus (P) fertiliser at rates up to 240 kg P/ha. The Cd content of the triple superphosphate (TSP) was 151 mg/kg. All 4 sites were on intensively cropped, high P-fixing krasnozem soils in north-western Tasmania, with concentrations of Colwell-extractable P ranging from 112 to 210 mg/kg. All sites showed economic yield responses to banded P, but broadcast P was much less effective except at the site where the response to banded P was least. Yield responses came mostly through increased tuber number, but at 1 site the tubers were also bigger. There was no effect of P on tuber size distribution or specific gravity. Increasing rates of banded TSP increased tuber Cd concentrations by 50-300% at the 3 sites where they were measured; broadcast TSP had little effect. Tubers from the site with pH 6.0 had much higher Cd concentrations than those from the sites with pH 6.5 and 6.6. Petiole Cd concentrations were about 5 times greater than tuber concentrations.



Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 321
Author(s):  
Stefan Cristian Prazaru ◽  
Giulia Zanettin ◽  
Alberto Pozzebon ◽  
Paola Tirello ◽  
Francesco Toffoletto ◽  
...  

Outbreaks of the Nearctic leafhopper Erasmoneura vulnerata represent a threat to vinegrowers in Southern Europe, in particular in North-eastern Italy. The pest outbreaks are frequent in organic vineyards because insecticides labeled for organic viticulture show limited effectiveness towards leafhoppers. On the other hand, the naturally occurring predators and parasitoids of E. vulnerata in vineyards are often not able to keep leafhopper densities at acceptable levels for vine-growers. In this study, we evaluated the potential of two generalist, commercially available predators, Chrysoperla carnea and Orius majusculus, in suppressing E. vulnerata. Laboratory and semi-field experiments were carried out to evaluate both species’ predation capacity on E. vulnerata nymphs. The experiments were conducted on grapevine leaves inside Petri dishes (laboratory) and on potted and caged grapevines (semi-field); in both experiments, the leaves or potted plants were infested with E. vulnerata nymphs prior to predator releases. Both predator species exhibited a remarkable voracity and significantly reduced leafhopper densities in laboratory and semi-field experiments. Therefore, field studies were carried out over two growing seasons in two vineyards. We released 4 O. majusculus adults and 30 C. carnea larvae per m2 of canopy. Predator releases in vineyards reduced leafhopper densities by about 30% compared to the control plots. Results obtained in this study showed that the two predators have a potential to suppress the pest density, but more research is required to define appropriate predator–prey release ratios and release timing. Studies on intraguild interactions and competition with naturally occurring predators are also suggested.



Author(s):  
Yi Huang ◽  
Yunze Xu ◽  
Xiaona Wang ◽  
Shide Song ◽  
Lujia Yang

Reinforced concrete is one of the most widely used construction materials for marine structures. Due to the abundance of the aggressive ions such as chloride ions and sulfate ions in the seawater, the reinforcement exposed to the marine and costal environment are exposed to a high corrosion risk. Localized corrosion will occur once the passive film on the rebar is damaged. In this work, the corrosion behavior of the steel in the simulated pore solution containing with both sulfate ions and chloride ions are studied by using cyclic potentialdynamic polarization methods and the corrosion morphologies observed using scanning electron microscope (SEM). The test results show that the initial rebar corrosion is caused by the absorption of the chloride ions in the passive film. The sulfate ions nearly had no effect on the corrosion of the rebar in pore solution and it can further mitigate the pitting corrosion in chloride containing pore solution.



Geology ◽  
2019 ◽  
Vol 48 (2) ◽  
pp. 145-148 ◽  
Author(s):  
Hao Cui ◽  
Richen Zhong ◽  
Yuling Xie ◽  
Xueyin Yuan ◽  
Weihua Liu ◽  
...  

Abstract The presence of sulfate-rich fluids in natural magmatic hydrothermal systems and some carbonatite-related rare earth element (REE) deposits is paradoxical, because sulfate salts are known for their retrograde solubility, implying that they should be insoluble in high-temperature geofluids. Here, we show that the presence of quartz can significantly change the dissolution behavior of Na2SO4, leading to the formation of extremely sulfate-rich fluids (at least 42.8 wt% Na2SO4) at temperatures &gt;∼330 °C. The elevated Na2SO4 solubility results from prograde dissolution of immiscible sulfate melt, the water-saturated solidus of which decreases from ≥∼450 °C in the binary Na2SO4-H2O system to ∼270 °C in the presence of silica. This implies that sulfate-rich fluids should be common in quartz-saturated crustal environments. Furthermore, we found that the sulfate-rich fluid is a highly effective medium for Nd mobilization. Thermodynamic modeling predicts that sulfate ions are more effective in complexing REE(III) than chloride ions. This reinforces the idea that REEs can be transported as sulfate complexes in sulfate-rich fluids, providing an alternative to the current REE transport paradigm, wherein chloride complexing accounts for REE solubility in ore fluids.



2016 ◽  
Vol 7 (2) ◽  
pp. 9-12
Author(s):  
Ryo Oda ◽  
Ryota Ichihashi

Previous field experiments have found that artificial surveillance cues facilitated prosocial behaviors such as charitable donations and littering. Several previous field studies found that the artificial surveillance cue effect was stronger when few individuals were in the vicinity; however, others reported that the effect was stronger in large groups of people. Here, we report the results of a field study examining the effect of an artificial surveillance cue (stylized eyes) on charitable giving. Three collection boxes were placed in different locations around an izakaya (a Japanese-style tavern) for 84 days. The amount donated was counted each experimental day, and the izakaya staff provided the number of patrons who visited each day. We found that the effect of the stylized eyes was more salient when fewer patrons were in the izakaya. Our findings suggest that the effect of the artificial surveillance cue is similar to that of “real” cues and that the effect on charitable giving may weaken when people habituate to being watched by “real” eyes. 



Author(s):  
V. V. Shevchuk ◽  
T. N. Potkina ◽  
A. I. Vaitenka ◽  
O. V. Smetanina

The excess of magnesium chloride brines is formed during the polymineral ores processing in order to obtain potassium sulfate. One way to regenerate such brines is to produce artificial carnallite. It is necessary to purify these brines from sulfates for their further use as raw materials for the artificial carnallite production. In this work, the process of desulfurization of magnesium chloride brines with a solution of calcium chloride is studied. The temperature and the processing time, the magnesium chloride solutions concentration and the consumption of desulfurizing agent (calcium chloride) influence on the degree of magnesium chloride solutions purification from sulfate ions was determined. It has been established that almost all sulfate ions interact with calcium ion in 15 minutes and the desulfurization degree reaches 98,08 %. The increase in duration of the suspension mixing is necessary in order to establish equilibrium in the system and relieve the supersaturation in the solution. It has been shown that with increasing solutions saturation with MgCl2, the degree of the magnesium chloride brines purification from SO4 2– ion increases. Complete precipitation of calcium sulfate requires a certain excess concentration of calcium chloride.



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