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1.
Phosphorus availability in chicken manure is lower with increased stockpiling period, despite a larger orthophosphate content 总被引:2,自引:0,他引:2
Background and aims
The relative proportions of phosphorus (P) forms present in manure will determine the overall availability of manure P to plants; however, the link between the forms of P in manures and manure P availability is unclear. This study compares the bioavailability and P speciation of three manures of different stockpiling duration: less than 1 month, 6 months and 12 months; manures were collected concurrently from a single poultry farm.Methods
Bioavailability to wheat in a glasshouse trial was measured using an isotopic dilution method with manure added at an application rate equivalent to 20 kg P ha?1. Phosphorus speciation was measured by 31P nuclear magnetic resonance (NMR) spectroscopic analysis of NaOH-EDTA extracts of the manures.Results
The addition of all manures significantly increased shoot biomass and P concentration, with the fresh manure having the greatest effect. Addition of the fresh manure resulted in the largest labile P pool, highest manure P uptake and manure P recovery, while the manure stockpiled for 12 months resulted in the lowest manure P uptake and manure P recovery. NMR analysis indicated that there was more monoester organic P, especially phytate, in manure stockpiled for shorter periods, while the proportion of manure P that was orthophosphate increased with stockpiling time.Conclusions
Together, these results imply that although the proportion of total P in the manures detected as orthophosphate was higher with longer stockpiling, only a fraction of this orthophosphate was plant-available. This suggests the availability of P from orthophosphate in manures decreases with longer stockpiling time in much the same way that P from orthophosphate in mineral fertilizer becomes less available in soil over time. 相似文献2.
Aims
The objective of this study was to investigate the role of transpiration on accumulation and distribution of thallium (Tl) in young durum wheat (Triticum turgidum L. var ‘Kyle’) and spring canola (Brassica napus L. cv ‘Hyola 401’) plants.Methods
Seedlings were grown hydroponically and exposed to Tl(I) under different high relative humidity (RH) conditions which resulted in different rates of transpiration among treatments. Plants were harvested prior to exposure, after a dark period of 9 (wheat) or 10?h (canola), and after 24?h of exposure. Harvested plant material was digested and analyzed for Tl by GFAAS.Results
Our results indicated that accumulation and distribution of Tl by plants was dependent on plant species, Tl(I) dose, duration of exposure and RH, but that the effect of RH was influenced by plant species and Tl dose. Plants exposed to Tl(I) under different RH conditions did not accumulate more Tl overall. In wheat, shoots with higher transpiration rates contained a higher Tl concentration. In canola, the rate of transpiration did not consistently affect the concentration of Tl in shoots.Conclusions
Overall, our results suggest that accumulation and translocation of Tl by plants is influenced by environmental factors that affect transpiration, in addition to soil characteristics. 相似文献3.
Background and Aims
Soy is currently the most important biodiesel feedstock crop in the U.S., but canola is an attractive alternative because of its potential for greater oil yields. Nevertheless, factors other than oil yield must be considered in the choice of biodiesel feedstock crop. For example, soy is mycorrhizal and canola is not. We examined the consequences of soy and canola crops to subsequently-grown maize, which is mycorrhizal. We hypothesized that canola would reduce mycorrhization, P uptake and yield of subsequently-grown maize when compared to soy, and that winter cover cropping with wheat (mycorrhizal) would ameliorate canola’s negative impacts.Methods
We established four rotations with two contrasts: either soy or canola in year 1, and with or without winter cover crops, followed by two years of maize.Results
In year 2, mycorrhizal colonization, shoot P concentration and yield of maize were reduced following canola compared to soy. Nevertheless, many of the former canola plots produced maize with much lower growth than did the former soy plots irrespective of mycorrhizal colonization, shoot N or shoot P concentrations. Cover cropping with wheat did not ameliorate these negative effects. The negative effects of canola were temporary as they did not occur in the second year of maize.Conclusions
The negative effects of canola observed in the first year of maize were coincident with a reduction in mycorrhizal colonization, but some other phenomenon appears to be causal, possibly allelopathy. Winter cover cropping was largely ineffective in ameliorating the negative effects of canola on maize. 相似文献4.
The effect of transpiration on selenium uptake and mobility in durum wheat and spring canola 总被引:6,自引:0,他引:6
Heidi Renkema Amy Koopmans Leanne Kersbergen Julie Kikkert Beverley Hale Edward Berkelaar 《Plant and Soil》2012,354(1-2):239-250
Aims
The objective of this study was to determine the relative importance of transpirational pull, Se speciation, sulfate and species on Se accumulation by plants, in order to determine which of these factors must be considered in the future development of models to predict Se accumulation by plants.Methods
Seedlings of durum wheat (Triticum turgidum L. var durum cv ‘Kyle’) and spring canola (Brassica napus L. var Hyola 401) were grown hydroponically and exposed to SeO 4 2- (selenate) with or without SO 4 2- (sulfate), or to HSeO 3 - (biselenite) under different transpiration regimes altered through ‘low’ (~50%) or ‘high’ (~78%) relative humidity (RH). Plants were harvested after 0, 8, 16, or 24?h exposures, digested, and analyzed for Se by GFAAS.Results
Accumulation and distribution of Se by plants is dependent on plant species, Se speciation in the nutrient solution, SO 4 2- competition, and transpiration regimes. Canola accumulated and translocated more Se than wheat. In wheat and canola, the greatest accumulation and translocation of Se occurred when plants were exposed to SeO 4 2- without SO 4 2- compared to solutions of SeO 4 2- with SO 4 2- or HSeO 3 2- . Wheat plants exposed to SeO 4 2- and SO 4 2- had an increased Se accumulation and translocation under increased transpiration rates than when exposed to SeO 4 2- without SO 4 2- or HSeO 3 2- . On the other hand, increases in transpiration increased the translocation of Se to canola shoots when exposed to HSeO 3 - more than any other treatments.Conclusions
Overall, our results suggest that plant species is the most important factor influencing Se accumulation and translocation, but that these endpoints can be modified by climate and specific soil Se or S content. Models to predict accumulation of Se by plants must consider all of these factors to accurately calculate the mechanisms of uptake and translocation. 相似文献5.
Background and aims
Crop phosphorus (P) content is controlled by P uptake from both banded P fertiliser and from P throughout the soil profile. These P supply factors are in turn controlled by soil, climatic and plant factors. The aim of this experiment was to measure the contribution of fertiliser, topsoil and subsoil P to wheat plants under wet and dry growing season conditions.Methods
An isotopic tracer technique was used to measure P uptake from fertiliser at seven agricultural field sites under wet and dry growing season conditions. At three of these sites a dual isotopic technique was used to distinguish between wheat uptake of P from fertiliser, topsoil (0–15 cm) and subsoil (below 15 cm).Results
The amount of P fertiliser used by wheat was in the order of 3–30% of the P applied and increased with increasing rainfall. Topsoil P was the most important P source, but when sufficient P was present in the subsoil, P fertiliser addition stimulated the use of subsoil P.Conclusions
Most crop P uptake was from the topsoil, however P fertiliser banded below the seed increased plant P uptake and stimulated the use of subsoil P in one soil type in a decile 7 (above average rainfall) growing season. 相似文献6.
Background and Aims
Crop residues are important for the redistribution of alkalinity within soils. A net increase in pH following residue addition to soil is typically reported. However, effects are inconsistent in the field due to confounding soil processes and agronomic practises.Methods
A column experiment investigated the effects of canola, chickpea and wheat residues, differing in alkalinity content and C:N ratio, on soil pH changes in a Podosol (Podzol; initial pH 4.5) and Tenosol (Cambisol; initial pH 6.2) under field conditions.Results
Residues (10 g dry matter kg-1 soil; 0–10 cm) increased soil pH, and temporal changes in alkalinity depended on the residue and soil type. Alkalinity was generated via abiotic association reactions between H+ and added organic matter and via ammonification and decarboxylation processes during decomposition. Alkalinity from canola and chickpea residues moved down the soil profile (10–30 cm) and was attributed to nitrate immobilisation and organic anion decomposition by soil microbes.Conclusions
The application of residues to acid and moderately acid soils increased the pH of both topsoil and subsoils, which persisted over 26 months. Maximal increase of pH observed at 3 months was correlated with the concentration of excess cations in the residues. 相似文献7.
Selenium accumulation in durum wheat and spring canola as a function of amending soils with selenite, selenate and or sulphate 总被引:3,自引:0,他引:3
Aims
A comparison was performed between plant species to determine if extractable, rather than total soil Se, is more effective at predicting plant Se accumulation over a full growing season.Methods
Durum wheat (Triticum turgidum L.) and spring canola (Brassica napus L.) were sown in potted soil amended with 0, 0.1, 1.0, or 5.0 mg kg?1 Se as SeO4 2? or SeO3 2?. In addition, SeO4 2?-amended soils were amended with 0 or 50 mg kg?1 S as SO4 2?. Soils were analyzed for extractable and total concentration of Se ([Se]). Twice during the growing season plants were harvested and tissue [Se] was determined.Results
Plants exposed to SeO3 2? accumulated the least Se. Fitted predictive models for whole plant accumulation based on extractable soil [Se] were similar to models based on total [Se] in soil (R2?=?0.73 or 0.74, respectively) and selenium speciation and soil [S] were important soil parameters to consider. As well, soil S amendments limited Se toxicity.Conclusions
Soil quality guidelines (SQGs) based on extractable Se should be considered for risk assessment, particularly when Se speciation is unknown. Predictive models to estimate plant Se uptake should include soil S, a modifier of Se accumulation. 相似文献8.
Wheat leaf properties affecting the absorption and subsequent translocation of foliar-applied phosphoric acid fertiliser 总被引:1,自引:0,他引:1
Background and aims
Although foliar fertilisation using liquid forms of phosphorus (P) is not a new concept, its adoption has been hindered by a limited understanding of the variability in performance of fluid forms of foliar P applied to broadacre crops. There is a need to identify how the surface structure of leaves influences the absorption and subsequent translocation of foliar-applied P in above ground plant parts.Methods
This study examined the surface properties of wheat leaves using scanning electron microscopy and measured the recovery of foliar-applied fertiliser that was labelled with either 32P or 33P from both the adaxial (upper) and abaxial (lower) leaf sides into untreated plant parts.Results
We found that the adaxial leaf surface absorbed and translocated more foliar-applied P away from the treated leaf than the abaxial surface, likely related to the higher abundance of trichomes and stomata present on that side of the leaf. The recovery of the foliar-applied fertiliser varied with rate and timing of application; ranging from <30 % to as much as 80 % of the adaxial-applied fertiliser translocated from the treated leaf into the wheat ear.Conclusions
This study demonstrated that the differences in surface morphological features between leaf sides influenced the combined absorption and subsequent translocation of foliar-applied P in the above ground plant parts. This is due to a direct effect on the foliar pathway and/or due to differences in wettability affecting both the leaf coverage and drying time of fertilisers on the leaves. Although foliar fertilisation in this study contributed less than 10 % of the total P in the plant, it provided a more efficient pathway for P fertilisation than soil-applied P. 相似文献9.
M. Coulis L. Bernard F. Gérard P. Hinsinger C. Plassard M. Villeneuve E. Blanchart 《Plant and Soil》2014,379(1-2):149-160
Background and aims
Intercropping of legumes and cereals appears as an alternative agricultural practice to decrease the use of chemical fertilizers while maintaining high yields. A better understanding of the biotic and abiotic factors determining interactions between plants in such associations is required. Our study aimed to analyse the effect of earthworms on the legume–cereal interactions with a focus on the modifications induced by earthworms on the forms of soil phosphorus (P).Methods
In a glasshouse experiment we investigated the effect of an endogeic earthworm (Allolobophora chlorotica) on the plant biomass and on N and P acquisition by durum wheat (Triticum turgidum durum L.) and chickpea (Cicer arietinum L.) either grown alone or intercropped. The modifications of the different organic and inorganic P forms in the bulk soil were measured.Results
There was no overyielding of the intercrop in the absence of earthworms. Earthworms had a strong influence on biomass and resource allocation between roots and shoots whereas no modification was observed in terms of total biomass production and P acquisition. Earthworms changed the interaction between the intercropped species mainly by reducing the competition for nutrients. Facilitation (positive plant–plant interactions) was only observed for the root biomass and P acquisition in the presence of earthworms. Earthworms decreased the amount of organic P extracted with NaOH (Po NaOH), while they increased the water soluble inorganic P (Pi H2O) content.Conclusions
In this experiment, earthworms could be seen as “troubleshooter” in plant–plant interaction as they reduced the competition between the intercropped species. Our study brings new insights into how earthworms affect plant growth and the P cycle. 相似文献10.
Uptake of zinc and phosphorus by plants is affected by zinc fertiliser material and arbuscular mycorrhizas 总被引:2,自引:0,他引:2
Stephanie J. Watts-Williams Terence W. Turney Antonio F. Patti Timothy R. Cavagnaro 《Plant and Soil》2014,376(1-2):165-175
Background and Aims
Water solubility of zinc (Zn) fertilisers affects their plant availability. Further, simultaneous application of Zn and phosphorus (P) fertiliser can have antagonistic effects on plant Zn uptake. Arbuscular mycorrhizas (AM) can improve plant Zn and P uptake. We conducted a glasshouse experiment to test the effect of different Zn fertiliser materials, in conjunction with P fertiliser application, and colonisation by AM, on plant nutrition and biomass.Methods
We grew a mycorrhiza-defective tomato genotype (rmc) and its mycorrhizal wild-type progenitor (76R) in soil with six different Zn fertilisers ranging in water solubility (Zn sulphate, Zn oxide, Zn oxide (nano), Zn phosphate, Zn carbonate, Zn phosphate carbonate), and supplemental P. We measured plant biomass, Zn and P contents, mycorrhizal colonisation and water use efficiency.Results
Whereas water solubility of the Zn fertilisers was not correlated with plant biomass or Zn uptake, plant Zn and P contents differed among Zn fertiliser treatments. Plant Zn and P uptake was enhanced when supplied as Zn phosphate carbonate. Mycorrhizal plants took up more P than non-mycorrhizal plants; the reverse was true for Zn.Conclusions
Zinc fertiliser composition and AM have a profound effect on plant Zn and P uptake. 相似文献11.
Peng Wang Liesje Mommer Jasper van Ruijven Frank Berendse Trofim C. Maximov Monique M. P. D. Heijmans 《Plant and Soil》2016,406(1-2):55-69
Background &; aims
Elevated atmospheric CO2 (eCO2) can affect soil-plant systems via stimulating plant growth, rhizosphere activity and the decomposition of added (crop residues) or existing (priming) soil organic carbon (C). Increases in C inputs via root exudation, rhizodeposition and root turnover are likely to alter the decomposition of crop residues but will ultimately depend on the N content of the residues and the soil.Methods
Two soil column experiments were conducted under ambient CO2 (aCO2, 390 ppm) and eCO2 (700 ppm) in a glasshouse using dual-labelled (13C/15N) residues of wheat (Triticum aestivum cv. Yitpi) and field pea (Pisum sativum L. cv. PBA Twilight). The effects of eCO2 and soil N status on wheat rhizosphere activity and residue decomposition and also N recovery from crop residues with different N status (C/N ratio 19.4–115.4) by different plant treatments (wheat, wheat + 25 mg N kg?1 and field pea).Results
Total belowground CO2 efflux was enhanced under eCO2 despite no increases in root biomass. Plants decreased residue decomposition, indicating a negative rhizosphere effect. For wheat, eCO2 reduced the negative rhizosphere effect, resulting in greater rates of decomposition and recovery of N from field pea residues, but only when N fertiliser was added. For field pea, eCO2 enhanced the negative rhizosphere effect resulting in lower decomposition rates and N recovery from field pea residue.Conclusions
The effect of eCO2 on N utilisation varied with the type of residue, enhancing N utilisation of wheat but repressing that of field pea residues, which in turn could alter the amount of N supplied to subsequent crops. Furthermore, reduced decomposition of residues under eCO2 may slow the formation of new soil C and have implications for long-term soil fertility.12.
Estimating belowground nitrogen inputs of pea and canola and their contribution to soil inorganic N pools using 15N labeling 总被引:1,自引:0,他引:1
Background and aims
Crop species grown in a diversified crop rotation can influence soil N dynamics to varying degrees due to differences in the quantity and quality of the residues returned to the soil. The aim of this study was to quantify the contribution of N rhizodeposition by canola (Brassica napus L.) and pea (Pisum sativum L.) to the crop residue N balance and soil inorganic N pool.Methods
Canola and pea were grown in a soil-sand mixture and were subject to cotton-wick 15N labeling in a greenhouse experiment. Nitrogen-15 recovered in the soil and roots were used to estimate N rhizodeposition.Results
Belowground N, including root N and N rhizodeposits, comprised 70 % and 61 % of total crop residue N for canola and pea, respectively. Canola released the greatest amount of total root-derived N to the soil, which was related to greater root biomass production by canola. However, root-derived N in the soil inorganic N pool was greater under pea (13 %) than canola (4 %).Conclusions
Our results show a significant belowground N contribution to total crop residue from pea and canola. Further investigation is required to determine whether input of the more labile N rhizodeposits of pea improves soil N supply to succeeding crops or increases the potential for N loss from the soil system relative to canola. 相似文献13.
Arbuscular mycorrhizas are beneficial under both deficient and toxic soil zinc conditions 总被引:2,自引:0,他引:2
Stephanie J. Watts-Williams Antonio F. Patti Timothy R. Cavagnaro 《Plant and Soil》2013,371(1-2):299-312
Background and aims
Arbuscular mycorrhizas (AM) play different roles in plant Zn nutrition depending on whether the soil is Zn-deficient (AM enhancement of plant Zn uptake) or Zn-toxic (AM protection of plant from excessive Zn uptake). In addition, soil P concentration modifies the response of AM to soil Zn conditions. We undertook a glasshouse experiment to study the interactive effects of P and Zn on AM colonisation, plant growth and nutrition, focusing on the two extremes of soil Zn concentration—deficient and toxic.Methods
We used a mycorrhiza-defective tomato (Solanum lycopersicum) genotype (rmc) and compared it to its wild-type counterpart (76R). Plants were grown in pots amended with five soil P addition treatments, and two soil Zn addition treatments.Results
The mycorrhizal genotype generally thrived better than the non-mycorrhizal genotype, in terms of biomass and tissue P and Zn concentrations. This was especially true under low soil Zn and P conditions, however there was evidence of the ‘protective effect’ of mycorrhizas when soil was Zn-contaminated. Above- and below-ground allocation of biomass, P and Zn were significantly affected by AM colonisation, and toxic soil Zn conditions.Conclusions
The relationship between soil Zn and soil P was highly interactive, and heavily influenced AM colonisation, plant growth, and plant nutrition. 相似文献14.
Amending soils of different texture with six compost types: impact on soil nutrient availability, plant growth and nutrient uptake 总被引:1,自引:0,他引:1
Background
Composts with different feedstocks may have differential effects on soil properties and plant growth which, may be further modulated by soil texture.Materials and methods
In a 77-day pot experiment in the glasshouse, we investigated the effect of a single application as mulch of six types of composts derived from different starting feedstocks in two soils (13% and 46% clay, referred to as S13 and S46) on soil physical, chemical and biological properties, plant growth and nutrient uptake. Composts were placed as 2.5?cm thick mulch layer on the soil surface and wheat plants were grown and harvested at 42?days and at 77?days (grain filling).Results
Composts differed in total and available N and P and particle size with C1, C3, C4 and C5 being fine-textured, whereas C2 and C6 were coarse-textured. Compost addition as mulch increased soil total organic C and EC, but had no effect on pH. In all treatments, cumulative soil respiration was higher in S13 than in S46 and was increased by compost addition with the greatest increase with C2 and C6. Compared to the unamended soil, most compost mulches (except C2) increased macroaggregate stability. Compost mulches significantly increased available P and N in both soils, except for C2. Compost mulches increased available N up to 6-fold in both soils with the strongest increase by C5. Most composts also increased wheat growth and shoot P and N concentrations with the greatest effect on plant N concentration by C5 and on plant P concentration by C4. However, C2 decreased shoot N and P concentrations compared to the unamended soil. Most compost mulches (except C2) increased mycorrhizal colonization by up to 50% compared to the unamended soil.Conclusions
Fine-textured compost mulches generally had a greater effect on soil properties and plant growth than coarse-textured composts. Despite distinct differences between the soils with respect to clay content, TOC and available P, the effect of the compost mulches on soil and plant properties was quite similar. 相似文献15.
Background and aims
The importance of seed Ni reserves for plant growth and N metabolism is poorly understood. This study investigated the effects of both seed Ni and externally supplied Ni on the impact of foliarly-applied urea and N-nutritional status of soybean.Methods
Soybean seeds were produced by growing plants in nutrient solutions containing different Ni levels, and their urease activities were measured. Plants were then grown from these seeds with or without external Ni. After treating half of the plants with foliar urea, the urea damage symptoms, elongation rates and chlorophyll concentrations were followed over one week. Biomass and mineral concentrations of different plant parts were determined.Results
Nickel supply at increasing rates improved seed yield by up to 25 %. Seeds with Ni concentrations varying between 0.04–8.32 mg.kg?1 were obtained. Depending on the Ni concentration, the seed urease activities differed up to 100-fold. Leaf damage due to foliar urea spray was significantly alleviated by higher seed Ni as well as external Ni supply. Higher Ni also promoted shoot elongation and improved chlorophyll concentrations. Nickel was 10-times more concentrated in the youngest part than in older leaves. In the absence of foliar urea, Ni enhanced the N concentration of the growing part of the shoot by up to 30 %.Conclusion
A better utilization of foliarly-applied urea-N is achieved in soybean when adequate Ni is supplied to plants by seed reserves and/or externally. High seed Ni levels are also required for preventing foliar urea damage and improving N remobilization. 相似文献16.
M. Asaduzzaman Min An James E. Pratley David J. Luckett Deirdre Lemerle 《Plant and Soil》2014,380(1-2):47-56
Aims
The allelopathic activity of canola (Brassica napus) germplasm was investigated using the important Australian weed, annual ryegrass (Lolium rigidum) as the target species.Methods
Three different canola plant densities (10, 20, and 30 seedlings/beaker) of each of 70 world-wide genotypes were tested in vitro in close proximity to annual ryegrass seedlings.Results
The allelopathic activity of canola, as measured by reduction in annual ryegrass root and shoot growth, increased with canola crop seedling densities. Density did not consistently influence shoot length of annual ryegrass. Greater shoot length suppression was observed in genotype cv. Rivette and BLN3343CO0402. The Australian genotype cv. Av-opal and the breeding line Pak85388-502 suppressed root length of ryegrass more than other genotypes, even at low densities. At the lowest density, the least allelopathic genotypes were cv. Barossa and cv. Cescaljarni-repka, although they became more allelopathic at higher density. An overall inhibition index was calculated to rank each of the canola genotypes. There were significant differences between canola genotypes in their ability to inhibit root and shoot growth in ryegrass.Conclusion
Considerable genetic variation exists among canola genotypes for their allelopathic effects on annual ryegrass. Further investigation is required to determine the allelopathic mechanisms, particularly to identify the responsible allelochemical(s) and the gene(s) controlling the trait. This research suggests that highly allelopathic canola genotypes can be potential for controlling weeds such as annual ryegrass in integrated weed management programs. 相似文献17.
Jian Jin Caixian Tang Roger Armstrong Clayton Butterly Peter Sale 《Plant and Soil》2013,368(1-2):315-328
Aims
The efficient management of phosphorus (P) in cropping systems remains a challenge due to climate change. We tested how plant species access P pools in soils of varying P status (Olsen-P 3.2–17.6 mg?kg?1), under elevated atmosphere CO2 (eCO2).Methods
Chickpea (Cicer arietinum L.) and wheat (Triticum aestivum L.) plants were grown in rhizo-boxes containing Vertosol or Calcarosol soil, with two contrasting P fertilizer histories for each soil, and exposed to ambient (380 ppm) or eCO2 (700 ppm) for 6 weeks.Results
The NaHCO3-extractable inorganic P (Pi) in the rhizosphere was depleted by both wheat and chickpea in all soils, but was not significantly affected by CO2 treatment. However, NaHCO3-extractable organic P (Po) accumulated, especially under eCO2 in soils with high P status. The NaOH-extractable Po under eCO2 accumulated only in the Vertosol with high P status. Crop species did not exhibit different eCO2-triggered capabilities to access any P pool in either soil, though wheat depleted NaHCO3-Pi and NaOH-Pi in the rhizosphere more than chickpea. Elevated CO2 increased microbial biomass C in the rhizosphere by an average of 21 %. Moreover, the size in Po fractions correlated with microbial C but not with rhizosphere pH or phosphatase activity.Conclusion
Elevated CO2 increased microbial biomass in the rhizosphere which in turn temporally immobilized P. This P immobilization was greater in soils with high than low P availability. 相似文献18.
Cynthia Grant Don Flaten Mario Tenuta Sukhdev Malhi Wole Akinremi 《Plant and Soil》2013,372(1-2):221-233
Background and aims
Limited information is available on how cadmium (Cd) applied in phosphate fertilizer interacts with soil and environmental conditions over time to affect crop Cd concentrations.Methods
Field studies from 2002 to 2009 at seven locations evaluated the cumulative effects of P fertilizer rate and Cd concentration on seed Cd concentration of durum wheat (Triticum turgidum L.) and flax (Linum usitatissiumum L.).Results
Soil characteristics and environment affected Cd availability. Durum wheat grain Cd increased with P fertilizer rate but effect on flaxseed Cd concentration was smaller. Cadmium concentration in fertilizer had a greater effect on flaxseed than durum wheat Cd concentration. Seed Cd concentration of both crops was greatest with the highest rate P fertilizer containing the highest Cd concentration. There was not a strong cumulative effect of fertilization over the 8 years of the study, indicating attenuation of Cd availability over time.Conclusions
Cadmium in phosphate fertilizer increases Cd available for crop uptake, but crop Cd concentration is also affected by soil characteristics and annual environmental conditions. Type of crop produced and soil and environmental characteristics that affect phytoavailability must be taken into account when assessing the Cd risk from P fertilization. 相似文献19.
Janneke M. Ravenek Liesje Mommer Eric J. W. Visser Jasper van Ruijven Jan Willem van der Paauw Annemiek Smit-Tiekstra Hannie de Caluwe Hans de Kroon 《Plant and Soil》2016,401(1-2):39-50
Background and aims
Measures of phosphorus (P) in roots recovered from soil underestimate total P accumulation below-ground by crop species since they do not account for P in unrecovered (e.g., fine) root materials. 33P-labelling of plant root systems may allow more accurate estimation of below-ground P input by plants.Methods
Using a stem wick-feeding technique 33P-labelled phosphoric acid was fed in situ to canola (Brassica napus) and lupin (Lupinus angustifolius) grown in sand or loam soils in sealed pots.Results
Recovery of 33P was 93 % in the plant-soil system and 7 % was sorbed to the wick. Significantly more 33P was allocated below-ground than to shoots for both species with 59–90 % of 33P measured in recovered roots plus bulk and rhizosphere soil. 33P in recovered roots was higher in canola than lupin regardless of soil type. The proportion of 33P detected in soil was greater for lupin than canola grown in sand and loam (37 and 73 % lupin, 20 and 23 % canola, respectively). Estimated total below-ground P accumulation by both species was at least twice that of recovered root P and was a greater proportion of total plant P for lupin than canola.Conclusion
Labelling roots using 33P via stem feeding can empower quantitative estimates of total below-ground plant P and root dry matter accumulation which can improve our understanding of P distribution in soil-plant systems.20.
XiaoJuan Wang Chris N. Guppy Laura Watson Peter W. G. Sale Caixian Tang 《Plant and Soil》2011,348(1-2):85-98