Effect of banded fertilizers on soil solution composition and short-term root-growth .2. Mono-ammonium and di-ammonium phosphates

Soil Research ◽  
1995 ◽  
Vol 33 (4) ◽  
pp. 689 ◽  
Author(s):  
PW Moody ◽  
DG Edwards ◽  
LC Bell
Keyword(s):  
Root Growth ◽  
Soil Solution ◽  
Root Elongation ◽  
Ammonium Phosphate ◽  
Contact Period ◽  
Solution Composition ◽  
Solution Ph ◽  
Organic C ◽  
Precipitation Reactions ◽  
Relative Root

A layer of mono- or di-ammonium phosphate (MAP and DAP, respectively) was placed in contact for 5 days with duplicate columns of soil at a water content equivalent to 10 kPa matric suction. This was designed to simulate the effects of banded fertilizer on soil solution composition. Five soils were used: 0-10 cm samples from a Kurosol, a Ferrosol, a Vertosol and a Kandosol, and a 50-60 cm sample from the Kandosol. After the contact period, soil sections were recovered at successive 5 mm intervals from the fertilizer layer, the last section being 45-60 mm from the layer. Soybean (Glycine max (L.) Merr.) seedlings were grown for 48 h in each section and relative root elongation was determined. Soil solution was then extracted from each section and analysed. The amount of inorganic P in the soil solution (P-i) was summed over all soil sections for each soil and each P source and was found to be correlated with distance of P movement from the simulated band (r = 0 . 792, P < 0.01). Of several soil chemical parameters of the control (unfertilized) soils regressed against Pi, the following showed significant (P = 0.05) negative correlations: Ca and Mg concentrations in the soil solution for Pi from both MAP and DAP, exchangeable Ca and Mg for DAP, and citrate-dithionite extractable Fe and Al for MAP. These results suggest that adsorption (and possibly precipitation) reactions with Fe and Al hydrous oxides contributed to the removal of P-i from solution in the presence of MAP. However, with DAP as the fertilizer source, precipitation reactions involving Ca and Mg were the predominant factors. Dissolved organic C in the soil solution increased adjacent to both DAP and MAP, with larger amounts in proximity to DAP being a consequence of the higher soil solution pH (~ 7). Soil solution Si increased in all soils adjacent to both DAP and MAP, with concentrations being higher in the MAP treatments. Dissolution of aluminosilicates in the acidic conditions near MAP (pH ~5) was the probable cause. Relative root elongation (RRE) of soybean was restricted in soil sections close to the fertilizer. When RRE was plotted against each of soil solution EC, NH3 activity, and calcium activity ratio (CAR), a single curvilinear function described the relationship between RRE and CAR for all soils and both P sources. It is concluded that a salt-induced Ca deficiency was the cause of restricted root growth in proximity to DAP and MAP, rather than an osmotic effect or NH3 toxicity.

Effect of banded fertilizers on soil solution composition and short-term root-growth .1. Ammonium-sulfate, ammonium-nitrate, potassium-nitrate and calcium nitrate

Soil Research ◽  
1995 ◽  
Vol 33 (4) ◽  
pp. 673 ◽  
Author(s):  
PW Moody ◽  
RL Aitken ◽  
SA Yo ◽  
DG Edwards ◽  
LC Bell
Keyword(s):  
Electrical Conductivity ◽  
Soil Solution ◽  
Soil Type ◽  
Root Elongation ◽  
Calcium Nitrate ◽  
Curvilinear Relationship ◽  
Contact Period ◽  
Solution Composition ◽  
Nitrate Salts ◽  
Relative Root

To simulate the effects of banded fertilizer on soil solution composition, layers of KNO3, NH4NO3, Ca(NO3)2.4H2O or (NH4)2SO4 were placed in contact with soil columns and allowed to equilibrate for 5 days at a moisture content equivalent to 10 kPa matric suction. Five soils were used in the columns: 0-10 cm samples from a Kurosol, a Ferrosol, a Vertosol and a Kandosol, and a 50-60 cm sample from the Kandosol. After the contact period, soil sections were recovered at successive 5 mm increments from the fertilizer layer, the last section being 45-50 mm from the layer. Soybean seedlings (Glycine max (L.) Merr. cv. Forrest) were grown for 48 h in each section and relative root elongation (RRE) was determined. Soil solution was then extracted from each section and analysed. Nitrate salts moved 50 mm in all soils (measured as a change in the electrical conductivity of the soil solution), but the movement of the sulfate salt was dependent on soil type and was least in the Ferrosol. As distance from the fertilizer band decreased, concentrations of cations in the soil solution increased, often reaching a plateau value. In all soils, solution Ca concentrations near the (NH4)2SO4 fertilizer band were lower than those further away, indicating precipitation of CaSO4.2H2O had occurred. This effect was particularly evident in the Vertosol and Ferrosol. The relationship between electrical conductivity of the soil solution (ECss) and Ca activity ratio (CAR) was dependent on soil type and fertilizer source. For the sulfate source, all soils exhibited a common curvilinear relationship in which CAR decreased with increasing ECss. However, for the nitrate salts, the Ferrosol and Vertosol had a higher CAR for a given ECss than the other soils because of the higher Ca2+ activities in their soil solutions. Relative root elongation decreased curvilinearly with increasing ECss, and a common curve was obtained for all soils and fertilizer sources. Although CAR decreased with increasing ECss, there was no common curve relating RRE to CAR for all soils and fertilizer sources. Osmotic effects, and not a salt-induced Ca deficiency, were therefore considered responsible for the decrease in RRE as distance from the fertilizer source decreased. A 10% reduction in RRE occurred at an ECss of 4.1 mS cm-1.

Effects of aluminium and calcium in the soil solution of acid soils on root elongation of Glycine max cv. Forrest

1988 ◽  
Vol 39 (3) ◽  
pp. 319 ◽  
Author(s):  
RC Bruce ◽  
LA Warrell ◽  
DG Edwards ◽  
LC Bell
Keyword(s):  
Root Growth ◽  
Soil Solution ◽  
Soil Ph ◽  
Activity Ratio ◽  
Acid Soils ◽  
Exchange Capacity ◽  
Al Toxicity ◽  
Solution Ph ◽  
Diagnostic Indices ◽  
Exchangeable Ca

In the course of three experiments, soybean (Glycerine max (L.) Merr.) cv. Forrest was grown in 21 soils (four surface soils and 17 subsoils) amended with liming materials (CaCO3 and Mg CO3) and soluble Ca salts (CaSO4.2H20 and CaCl2.2H2O). In most soils, the soluble salts increased concentrations and activities of Al species in solution to levels that restricted root growth, and MgCO3, induced a Ca limitation to root growth. Root lengths after three days were related to so11 and soil solution attributes.Suitable diagnostic indices for the prediction of Ca limitations to root growth were either Ca saturation of the effective cation exchange capacity or Ca activity ratio of the soil solution, which was defined as the ratio of the activity of Ca to the sum of the activities of Ca, Mg, Na, and K. Values corresponding to 90% relative root length (RRL) of soybean were 0.05 for the Ca activity ratio and 11% for Ca saturation. Calcium activity and Ca concentration in the soil solution and exchangeable Ca were less useful for this purpose.Soil Al saturation was not a good predictor of Al toxicity, but soil solution measurements were. The activities of Al3+ and AlOH2+ gave the best associations with RRL, and values corresponding to 90% RRL were 4 8M and 0.5 8M respectively. The results suggested that Al(OH)3� , Al(OH)2+, and AlSO4+, were not toxic species. Soil solution pH and soil pH measured in water were more sensitive indicators of root growth than soil pH measured in 0.01 M CaCl2.Using a Ca activity ratio of 0.05 and an Al3+ activity of 4 8M as diagnostic indices, none of the 20 soils in two experiments were toxic in Al, while 13 (all subsoils) were deficient in Ca. Thus the first limitation on root growth was Ca deficiency and not Al toxicity, in spite of high Al saturations and relatively low pH in these soils. However, Al toxicity could be induced by increasing the ionic strengths of soil solutions.

Effects of incubation time and filtration technique on soil solution composition with particular reference to inorganic and organically complexed Al

Soil Research ◽  
1991 ◽  
Vol 29 (2) ◽  
pp. 223 ◽  
Author(s):  
NW Menzies ◽  
LC Bell ◽  
DG Edwards
Keyword(s):  
Gamma Irradiation ◽  
Soil Solution ◽  
Solution Composition ◽  
Organic C ◽  
Major Cations ◽  
Soil Solutions ◽  
Incubation Periods ◽  
Ultra Filtration ◽  
Highly Weathered Soils ◽  
Filtration Technique

Soil solutions were extracted from surface and subsoil samples of highly weathered soils in the field moist state and from air-dry samples which had been re-wet and incubated at 28�C for 1 to 64 days. Soil solutions were analysed following filtration through 0.22 pm and 0-025 �m pore-diameter hembranes. Selected samples were also incubated following sterilization by gamma irradiation (50 kGy) to investigate the effects of microorganisims on soil solution C dynamics. Ultra-filtration did not affect the concentration of the major cations or anions but significantly reduced Al, Fe, Mn, Si and organic C concentration in some surface soil solutions extracted from field-moist samples and from re-wet air-dry samples after short incubation periods. The organically-complexed Al concentration in soil solution was significantly increased by air-drying and re-wetting soil; the organic Al concentration decreased with increased time of incubation to levels comparable with that present in field-moist samples. Inorganic monomeric Al reached a stable concentration, comparable with that in field moist samples, when air-dry soils were re-wet and incubated for 1 day. While gamma irradiation effectively sterilized the soil and stabilized the concentration of Al and organic C in solution, the magnitude of the changes in soil solution composition observed as a result of irradiation diminish the value of this finding.

scholarly journals The Response of Duckweed (Lemna minor L.) Roots to Cd and Its Chemical Forms

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Yan Xue ◽  
Jin-qin Wang ◽  
Jin Huang ◽  
Feng-ying Li ◽  
Ming Wang
Keyword(s):  
Growth Rate ◽  
Root Growth ◽  
Root Elongation ◽  
Lemna Minor ◽  
Weibull Model ◽  
Chemical Forms ◽  
Total Antioxidant ◽  
Relative Root Growth ◽  
Relative Root ◽  
Root Growth Rate

The response of duckweed (Lemna minor L.) roots to Cd and its chemical forms was investigated. The relative root growth rate and concentrations of Cd and its different chemical forms in the root, that is, ethanol-extractable (FE-Cd), HCl-extractable (FHCl-Cd), and residual fractions (Fr-Cd), were quantified. Weibull model was used to unravel the regression between the relative root elongation (RRL) with chemical forms of Cd. Parameters assessed catalase (CAT), peroxidases (POD), and superoxide dismutase (SOD), as well as malondialdehyde (MDA) and total antioxidant capacity (A-TOC). Our results show that both the relative root growth rate and relative frond number were affected by Cd concentrations. The chemical forms of Cd were influenced by Cd content in the medium. Relative root elongation (RRL) showed a significant correlation with chemical forms of Cd. Additionally, POD and SOD increased at lower Cd concentrations followed by a decrease at higher Cd concentrations (at more than 5 μM Cd). Moreover, MDA and A-TOC increased and CAT decreased with increasing Cd exposure. Furthermore, CAT showed a significant correlation with FHCl-Cd. Taken together, it can be concluded that the chemical forms of Cd are statistically significant predictors of Cd toxicity to duckweed and to the other similar aquatic plants.

scholarly journals Evaluation of Aluminum Sensitivity in Barrel Medic Germplasm

2016 ◽  
Vol 141 (3) ◽  
pp. 249-255 ◽  
Author(s):  
Yawadee Srimake ◽  
Susan C. Miyasaka
Keyword(s):  
Root Growth ◽  
Root Elongation ◽  
Arable Land ◽  
Acid Soils ◽  
Al Tolerance ◽  
Crop Species ◽  
Barrel Medic ◽  
Staining Score ◽  
Relative Root Growth ◽  
Relative Root

Aluminum (Al) toxicity in acid soils is a major constraint to global agricultural production, affecting ≈30% of the world’s arable land area. To study Al tolerance in barrel medic (Medicago truncatula), we assessed responses to excess Al in 91 accessions collected from different geographic regions. Root elongations were used to characterize the sensitivity of each accession. Seedlings were grown in an agarose medium that contained three levels of Al (50, 100, and 200 µm), and root elongation was measured at 72 hours after exposure to Al. The ratio of root elongation in the presence and absence of Al [relative root growth (RRG)] differed among accessions. At 50 µm Al, we observed the greatest range of intraspecific variation. Aluminum sensitivity of 30 accessions was tested further by hematoxylin staining. Relative root growth was regressed linearly against the visual staining score, and a significant, negative, linear relationship was found between RRG at 50 or 100 µm Al and the intensity of staining scores. Twelve selected accessions differing in their resistance were grown in Al-toxic soil to confirm their Al response. Such information could be useful in breeding or selecting for improved Al tolerance in barrel medic, as well as other crop species.

Aluminium speciation in seasonally dry high country soils, South Island, New Zealand

Soil Research ◽  
1999 ◽  
Vol 37 (5) ◽  
pp. 1005 ◽  
Author(s):  
M. L. Adams ◽  
P. D. McIntosh ◽  
R. D. Patterson ◽  
K. J. Powell
Keyword(s):  
Soil Solution ◽  
Root Elongation ◽  
S Phase ◽  
Al Toxicity ◽  
Uv Absorbance ◽  
Solution Ph ◽  
Seasonally Dry ◽  
Soil Solutions ◽  
Aluminium Speciation ◽  
Legume Growth

Soil solutions from an altitude sequence of South Canterbury high country soils (730– 1190 m) were analysed using a recently developed technique to obtain values for ‘free Al’ ([Al 3+ ]+[Al(OH) 2+ ]+[Al(OH)2 + ]+[AlF 2+ ]), an ‘organic-bound Al’ fraction, and the Al- complexation capacity (Al-CC). From 1979 these soils have been fertilised, oversown, and grazed. Since 1978, topsoils (0–7 . 5 cm) have become more acid, and average pH(H 2 O) (1 : 2 . 5 soil : H2O; n = 38) has fallen from 5 . 79 in 1978 to 5 . 25 in 1996. Despite this soil acidification, the current ‘free Al’ values are low (0 . 31–0 . 75 µМ) and are unlikely to limit legume growth. This conclusion was supported by root elongation experiments using Medicago sativa (Wairau lucerne). No significant correlation was observed between measured root elongation and either soil solution pH or ‘free Al’. Sunny aspects had higher ‘organic-bound Al’ and lower ‘free Al’ values. The values of p[Al 3+ ] calculated from ‘free Al’ were consistent with control of [Al 3+ ] by an Al(OH)3(s) phase rather than by organic matter. ‘Organic-bound Al’ correlated strongly with the concentration of humic substances in soil solution as estimated by the UV absorbance at 250 nm. The Al-CC decreased with a decrease in soil solution pH. Relative to the total reactive Al, the capacity of soil solutions to complex Al, as may be generated by acidification, was lower for the soils at lower elevations, pointing to potential for an earlier onset of Al toxicity at these sites.

Effects of calcium and aluminum in the soil solution of acid, surface soils on root elongation of mungbean

Soil Research ◽  
1994 ◽  
Vol 32 (4) ◽  
pp. 721 ◽  
Author(s):  
NW Menzies ◽  
DG Edwards ◽  
LC Bell
Keyword(s):  
Root Growth ◽  
Soil Solution ◽  
Root Length ◽  
Solid Phase ◽  
Ion Pairs ◽  
Exchange Capacity ◽  
Strongly Correlated ◽  
Surface Soils ◽  
Relative Root Length ◽  
Relative Root

Short term root growth bioassays using mungbean (Vigna radiata (L.) Wilczek) were conducted on 39 surface soils in the unamended state and following the addition of CaCO3 or CaSO4.2H2O. Root length after 48 h growth was related to solid phase and soil solution Ca and Al attributes. Suitable diagnostic indices for the prediction of Ca limitations to root growth were either Ca saturation of the cation exchange capacity or Ca activity ratio (CAR) defined as the ratio of the activity of ca2+ in the soil solution to the summed activities of Ca2+, Mg2+, Na+, K+ and Al3+. Values corresponding to 90% relative root length were 34% for Ca saturation and 0.10 for CAR. The activities of Al3+ and AlOH2+ were the Al attributes most strongly correlated with root growth; an Al3+ activity of 1.9 �m~ and an AlOH2+ activity of 0.46 �m corresponded to 90% relative root length. The results suggest that organically complexed Al and the ion pairs Al(OH)+2, Al(OH)04 and AlSO+4 are not plant-toxic. The most effective diagnostic criterion for A1 toxicity in this study was the calcium-aluminium balance (CAB), defined as 2 log(Ca2+) - 6 log(Al3+). The CAB value corresponding to 90% relative root length was 31. The correlation between root growth and CAB was further improved by inclusion of a pH term; this may indicate toxic effects of H+ per se.

scholarly journals Response of a Scots pine (Pinus sylvestris) stand to application of phosphorus, potassium, magnesium and lime. 2. Soil solution composition

1993 ◽  
Vol 41 (4) ◽  
pp. 267-289
Author(s):  
G. Arnold ◽  
I.L. Sweers ◽  
A. Van Diest
Keyword(s):  
Soil Solution ◽  
Scots Pine ◽  
Slow Release ◽  
Root Zone ◽  
Solution Composition ◽  
Solution Ph ◽  
Slow Release Fertilizers ◽  
Mg Addition ◽  
Scots Pine Forest ◽  
Potassium Magnesium

In 1985-88, a 25-yr-old Scots pine forest in Netherlands was limed (5 levels) and fertilized with P, K and Mg in a factorial design. This paper discusses the influence of P, K and Mg addition (as one treatment) and liming, on solute concentrations at depths of 30 cm, i.e. in the root zone (monitored September 1989 - April 1992) and 100-150 cm, i.e. below the root zone (April 1991). Liming increased NO3 concentrations at both depths. At 30 cm this effect of liming gradually vanished during the study period, concurrently with declining soil solution pH, while an increasing effect of PKMg on NO3 developed. Probably it took several years for nitrifying microflora to adapt to improved nutrient availability, while the effect of liming was instantaneous. These data show that besides liming, fertilization may increase NO3 leaching. NH4 was not affected by any treatment. Applied K and Mg compounds were easily soluble, and their soil solution concentrations were increased at both depths in PKMg-amended plots. Probably slow-release fertilizers would allow for a more efficient incorporation of K and Mg into the system's biomass. Reducing effects of liming on soluble Al were weak (30 cm) or absent (100-150 cm). Al at 30 cm did not reach concentrations known to be harmful to Scots pine, but Ca:Al ratios were critical in unlimed plots. No evidence was found for enhanced cation leaching caused by increased formation of nitric acid in limed plots.

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